Harley Twin Cam Engines Love Some Compression

[@GixxerFoo]

Do you prefer to keep a lower compression ratio or bump the compression ratio up for more power?

[@64Goef]

Never thought about going this route, thanks for sharing. Will give it some thought.😎👍

[@GixxerFoo]

It's not a bad way to go, Twin Cams really make some power with high compression and a good cam.

[@thewheel2023]

Bought a T.C. 88 with screaming eagle heads, air cleaner, thunder header 2 into 1 exhaust the bike has compression releases. I need to find octane booster.

[@kerrylewis2581]

This is a great topic to discuss. A minimum of 10.0 should be a baseline for almost all builds. I can't wait until I have a legit reason to remove my cylinders and heads.

[@scrumthebum2451]

@@thewheel2023 Octane boost is not that great. What I do for my shovelhead that detonates on pump gas is go to the drag strip and by 110 Sunoco & mix it 1/2 & 1/2 with 94 Sunoco comes up at 102 octane. You can mix more or less depending on your octane requirements

[@kerrylewis2581]

It's amazing what a slight bump in compression, minor headwork, and a cam will do for performance. Top that off with a great dyno tune and it's like a new engine. The sad part really is that they could and should be built this way.

[@GixxerFoo]

I totally agree, they should come from the factory like we build them in our garages. It really show us just how much potential they intentionally leave out of these engines.

[@simonkennedy6116]

This is what they call the Harley Tax

[@kerrylewis2581]

@@simonkennedy6116 Harley Tax because Harley Slax on performance

[@trailerparkcryptoking5213]

They design the engines to run on the shittiest gas/harshest climate in the world without engine destroying detonation! Otherwise the manufacturer would go bankrupt doing warranty work! Ultra conservative timing curves negate detonation and lean fuel meets EPA mandates. That’s why an aftermarket tune adds good power, more timing/fuel....

[@redbone6940]

Turned my stock 88" twin Cam into a 95". 585 S&S easy start cams. And 10/2 to 1 compression piston Dyno at 110HP. And 117 lbs. Baby really moves.

[@GixxerFoo]

Damn. That's some hella good numbers from a 95! Just goes to show what the right combination of parts can do!

[@RideToTheSun1]

What part of the country do you live in, and what shop did the work. Thanks

[@k9m42]

Did my 2009 fxdf with the SE stage 4 race kit with yellow race SE tuner, 10.5 to 1 compression, ventilator intake and SE slip on mufflers. My year had no catalytic. Ended up with a reliable 111 HP and 110 TQ. Bike runs great!

[@GixxerFoo]

That's awesome! That's a really solid amount of power and doing reliably is what it's all about.

[@ThePNWRiderWA]

If your running that low why not kick it up. We used to run cars at 11.5 to 1. Wrist pins, crutch assembly , valve springs needed to be increased and maybe a better oil pump. Why not when it’s time to rebuild it have some fun? If you are like me and a gear head be it bikes , cars or trucks it’s a no brainer. It’s something I like to do with my sons and pass the knowledge I have from my father to myself. When I was kid in the late 60s -70s the gas shortage hit. We used water injection as the gas was crap. Texas 93 octane is all over

[@GixxerFoo]

It's crazy what some increased compression will do for a motor, biggest problem is keeping them from knocking on pump gas. Gas quality varies so much when you're traveling, I've gotten stuck at some old 2 lane highway station with only what I assume was once 87 octane lol. That's why I carry some octane booster just to be safe.

[@life_behind_bars]

I finally pulled the trigger on my stage one upgrade. I went with a more budget friendly configuration. Screaming eagle heavy breather, FP3 tuner, and V&H straight shots. That's it for this season. That's give me another year of watching your videos before I decide on my next upgrade. 👍😎👍

[@GixxerFoo]

Great to hear! That's a solid setup really similar to what I run, I am very happy with mine!

[@life_behind_bars]

@@GixxerFoo ok so maybe that's not all for the season, I bought a saddlemen knuckle solo seat now too. 😏. I know I have a problem 🤣.

[@leonardstanford1877]

Your right on with more compression ! I don't even do stock rebuilds with out using Cometic MLS gaskets back in the day we always milled Evo heads .020 to wake them up but now we got thinner gaskets lots easier ! Your also right about checking valve to piston with stock pistons Back in 99 TC motors there weren't any good pistons & we had to machine the pistons for deeper & wider valve pockets for big valves & high lift cams !

[@GixxerFoo]

Great point! Cometic is the way to go in my opinion on gaskets! We've reused those things before time and time again, first time was a have to situation and it worked. These gasket thicknesses available is awersome!

[@robertbachant8257]

Just remember. The more duration the intake cam has the later that valve closes which lowered dynamic compression. 12:1 static compression could be perfect for pump gas if your cam has enough duration.

[@GixxerFoo]

You are correct! There's so much to calculating compression it's crazy, it all has to balance to be right!

[@kye9549]

So I'm looking at a WG right now. It's a built s&s motor top to bottom w/ 585 cams. It has 12.5:1 which seemed pretty high and I can't find any info online about Harleys with such high comp. Are you saying its not too high?

[@robertbachant8257]

@@kye9549 That seems high for that cam and 91 octane. If 93 is available in your area, it may be close but it wont be happy on days over 70 degrees.

[@kye9549]

@@robertbachant8257 we have 98 available. Plenty of hot days coming up though

[@michaelmitchell5909]

Good info man. I had my screamin eagle motor done last winter, kb domed pistons, heads were ported, andrews 57 cams, crank has 2 thou run out, which surprised the mechanic and me as well...10 over bore, hone, and decked gasket surfaces, hpi throttle body, bigger injectors, bassani 2 into 1 road rage 3 pipe, arlen ness velocity stack air filter, tune liscence from dyno jet and a proper dyno tune...runs awesome now for a 19 year old bike...2003 cvo road king.

[@GixxerFoo]

Nice work! Damn that's a laundry list of work done to that bike! Those are some beautiful bikes, especially that first year of the 103 Road King, I bet it runs damn good.

[@michaelmitchell5909]

@@GixxerFoo ....ya man, thanks for responding!....its really fun to ride now, it was befor when I first got it, but now it's like a steam loco!

[@timothygadbois7851]

After seeing this build I'm excited to see what mine is gonna do on the dyno . 100" S&S kit with 10:5:1 S&S cam plate and pump Woods 777 cams Woods lifters Fuelmoto pushrods Heads ported and polished with oversized valves and beehive springs , roller rockers and decked. 040 for about 11:1 compression. Tuned with a thundermax tuner. Appointment with dyno tuner next month. Not sure what the Hp and tq is but this thing is fun😁

[@GixxerFoo]

That bikes is gonna sound angry and run hard! Let me know what you end up with!

[@freddieweimann3602]

Raising compression was the way to go in the old days before all these kits.....

[@GixxerFoo]

The kits have really simplified building a motor, you can get parts that have been tested and proven to work together. You can even improve upon them yourself from there if you like.

[@rexstewart6111]

I have kept my 88 standard, apart from a change of exhaust cam which makes it run cooler. I like the fuel consumption of standard trim suits my riding. But I know a lot of guys up the power and that’s their right, it would be boring if we were all the same.

[@GixxerFoo]

Nothing wrong with keeping it simple, they are very reliable with just basic tuning, exhaust and air cleaner.

[@bigwu100]

What exhaust cam did you use. Running cooler sounds good to me.

[@rexstewart6111]

The guy who ordered the parts chose a cam which just keeps the exhaust opened a bit longer but I will ask him if he can find out for you.

[@TeensierPython]

Once again. This is true for all engines.

[@GixxerFoo]

That's true, all engines can benefit from a compression bump!

[@scottarmstrong1172]

Great info, as always. I wouldn't tear a motor down just to raise the compression, but if I were doing other work and had it mostly apart anyway then it is definitely worth it.

[@GixxerFoo]

Right on, not a good plan if it's got some miles on it. If it's low miles and you added a cam and changed your mind on compression I could see doing it then.

[@theodavies8754]

We have 99+ in the UK for now. Cams and the right operating temperature make a big difference. Don't judge the seat dyno for at least the first 10 minutes.

[@Mark-mm1ke]

Awesome. Love the content. I used a .0030 gasket when I did my heads. Dan Vance Racing did the work. I would recommend him any time. Talking my book, but he might be the best HD head guy out there. His back ground was racing. I use octane boost all the time. I don't have any problems, but I notice a significant increase in power. I think the gas we get today cut with ethanol is not that great. Not only an increase in power, but gas mileage, so it's a win win. Left the stock 103" pistons in. Someday I'll upgrade to a drop in 110", but the motor runs so good, I'm afraid to touch it now.

[@GixxerFoo]

That's awesome to hear! Yeah ethanol fuel is awful, I avoid it as much as possible.

[@Random-bm7ho]

I always hear how ethanol is bad, but every manufacturer designs the engine to run on it, ethanol is a form of alcohol, e-85 is essentially alcohol and has a 110 to 120 octane rating. I always run premium fuel 91 or better, but everything else like the daily, mowers etc get 87 and they work year in and year out. I think the "ethanol bad" myth is just that, a myth at this point.

[@Mark-mm1ke]

@@Random-bm7ho It's not that it's 'bad', but it definitely cuts the mileage. That's a fact. I run 91 also but like I said, I add in a octane booster and I love it. If you have never tried it, do! You will notice the difference I guarantee it.

[@Random-bm7ho]

@@Mark-mm1ke I usually run some of the Lucas fuel injection cleaner/lubricator stuff in every tank. It's just a stock 103, but I'm looking to add cams, upgrade the oil pump and cam plate, and maybe a thinner head gasket while I'm there. Engine has 18k on it. Just looking to wake it up some.

[@Mark-mm1ke]

@@Random-bm7ho I did a lot of searching on cam profiles before I bot the Woods 222. Has the best low end torque of them all imo. So I went with that, V&H power duels, map, and air. Came out great. Next year did the heads. Wow, what a difference. Numbers were not all that much better, but the seat of the pants ride was! Here are the numbers. 116 torque, 103 Hp. Torque at 2000 rpm 100ft/lbs. Bike runs incredible. I also did both front and rear suspension from Terry Cable. I’ll never get another bike and not do that. Handles like a rice rocket! LOL Well, you get the picture.

[@bradballard2068]

KZbin buried your channel on me but I'm back. ✌️😎 Also, I wanted to thank you for your recommendation of the spherical bearing kit for my swing arm that was on a previous video. (That I can't find) I did the install on it and it works great. It took that torque kick out of the ass end of my bike when I get in the throttle. LoveLoveLove ! I appreciate all your uploads and your sound advice.

[@GixxerFoo]

Thank you! I really appreciate it! It's great to hear you got your bike straightened out and tracking right now!

[@jimedward8908]

As always, great vid, great info and not too long. I like the positive approach you use in your productions.

[@GixxerFoo]

Awesome! Thank you!

[@mikespencer9913]

I’ve got a Ducati as well as an FLSTN, so I don’t typically worry about peak HP or Torque. With all these videos, though, I’m starting to migrate over to the Dark Side. Thanks for all the awesome info!

[@tcb8295]

Gixxer, just viewing your video. Just returned home from week at Myrtle Beach Spring Bike Rally. Thanks for the video.

[@GixxerFoo]

Sweet! How was the rally out there?!

[@tcb8295]

@@GixxerFoo with the exception of the gas shortage issue due to the temp pipeline shutdown, it was awesome!! Lot's nice bikes, good people, and fun...and no masks!

[@rickymcu]

EVERY engine loves compression

[@nickc5341]

Currently getting my bike reworked. Had the 117 harley kit installed a few year ago on my 110 fat boy. Harley cams are crap. Also the kit advertised something like a 9.9:1 compression increase. I have a good 2 into 1 exhaust and used a power vision and I was not happy at all with the power as it was low for a 117. Was dyno'd at 108hp and 112 ft/lbs. So now my bike is with another guy re-doing the kit. I added a Tman 625ps cam and he cc'd the motor for more compression. He found that the 117 kit from harley makes a false claim on compression and is actually only making 9.5:1 instead of the claimed 9.9:1. So after he was done reworking the heads and all the motor is now making 11.1:1 compression. Of course this is static compression. Altitude where you live plays a huge role in what you set your static compression at and I'm at 2200 feet elevation and so 11.1:1 with my cam choice actually works out to 10.17:1 corrected compression so should be pump gas friendly. Waiting for the dyno results so I'll post them when it's complete and we will see the difference a cam swap and the added compression made.

[@scrumthebum2451]

Nick C Looked at the specs on that cam It closes at 41 sounds to short for 11:1 on pump gas & going to be hard on your starter. The elevation will help some but I’d be very careful listening for detonation

[@nickc5341]

@@scrumthebum2451 I have ACR. Also I talked to the guys at Tman personally and they recommended at least 11:1 compression to compensate for the higher elevation I'm at since the corrected compression will end up at 10.17:1 compression. Will allow for no issues with pump gas. I trust the guys at Tman have experience with this so. Also it's all about the tune. Just back off on the ignition timing and will help with detonation.

[@scrumthebum2451]

@@nickc5341 Ok sounds like you have researched it and have the advice of Tman. Elevation must play a larger factor than I thought. Good luck sounds like a fun build 👍

[@Cheaps928]

are tman cams good compared to wood cams? im looking to eventually go stage 3 on my stock 103 street bob. any recommendations? i dont care about going fast, having a lot of torque and some hp is good for me. i heard tman cams are quiet compared to wood cams

[@nickc5341]

@@Cheaps928 the 625 cam I'm using is very quiet. Wood cams are great too from everything I seen. I personally would love to try wood's tw999 cam. I've spent too much money already though so maybe years down the road if I need a rebuild I'll try and new cam. With the tman 625 I'm now making 120hp and 124 torque sae on the dyno. Would have made more if the elevation was closer to sea level but I'm satisfied. I'd really love to get a new bike with a Milwaukee engine and have tman put in their 139 kit. They made 166hp and 170 torque on at 2021 fat boy. Insane! Bet that wasn't cheap tho!

[@cameronbartley6139]

I sure did wake my 103 up... I installed a stage v 103 - 110 kit with 10:5:1 pistons, 259E cams, cnc ported heads 58mm Throttle body ,S&S Cam plate and oil pump, RC head pipe , Dyna jet powder commander v, Getting ready to have it dyno tuned . I'll let you know what the results are.

[@GixxerFoo]

You got the right setup right there, the compression is gonna make all the difference with that setup! I'd imagine you won't be disappointed at all!

[@jeffkinsey3801]

125 h.p. ?

[@jamesball2128]

My Twin Cam B is @ about 9.75:1 with S&S Super Stock 79cc heads, .040LD and an Andrews 37g

[@GixxerFoo]

That's a solid range to be in, great power and nothing too crazy!

[@tl5108]

For an everyday/road trip bike I like keeping the comp low. Never know what’s gonna be available for fuel. Rode to florida from PA hit a couple spots where the only fuel available was 87

[@GixxerFoo]

Agreed! Been there too! I always carry those little octane booster packets just for that situation.

[@EXwifeKILLER]

Yeah. Had that happen. Had to burn 89 and my mileage went straight to hell. Went from 45mpg to about 30

[@trailerparkcryptoking5213]

Or you can have a road trip tune taking 2-3* of timing out, ta-da.....excuses are just that, excuses....😎

[@tl5108]

@@trailerparkcryptoking5213 can’t adjust 88 timing without getting an aftermarket ignition box

[@trailerparkcryptoking5213]

@@tl5108 well get one.....can’t have a proper tune without the ability to adjust timing curve. Anything from the factory has an extremely conservative timing curve so that it will run in harshest environment on earth on the shittiest gasoline on earth, in an effort to not detonate and create warranty work! If you have decent air and fuel then you can run more aggressive spark timing and get better performance and fuel mileage! Buy Dr Christopher Jacobs book Performance Ignitions it’s an absolute must read!

[@fixerny]

I have a completely stock 96 in a 2007 Road King - it has been a milkshake mixer since I brought it home new from the dealer. My 2003 Stage 4 twin cam Road King is markedly smoother - much less shaking. Motor mounts on both are fine. How about a video on how to cut back on excessive shaking and vibration? I’ve heard everything from “experts” on this subject (flywheel, idle speed, crank balancing, handlebar dampers etc.,). What’s the best way to cut the Shake?

[@GixxerFoo]

Honestly just making sure the mounting system is good shape and everything is tight. Getting into the engine flywheel and crank balancing helps. Crank run out can cause excessive vibration, it's hard to avoid with Harleys since no two engines are alike.

[@RJ67.]

Nice upgrade to the shelf brother!

[@GixxerFoo]

Thank you, finally got that replaced after all these years!

[@westoniii]

+ Compression made my exhaust note pretty snappy in the old sportster

[@GixxerFoo]

Before they started boring them out to 1250 high compression was the way to go! Now we can go 1275 with high compression thanks to Hammer Performance.

[@westoniii]

@@GixxerFoo this is on an old ironhead man. Stock stroke, .30 over 1000 cc, wiseco 10:1 slugs, head work and cams. She's mean.

[@MrCobalty]

Every time I got a question no shit here you are talking about what I need lol

[@GixxerFoo]

That's awesome! I try to cover as many different Harley topics as I can!

[@Bluis5445]

How you gonna mention woods 777 and not give me a shout out! Lmao! I’ve been praising those cams for a longggg time! High compression over low compression any day!

[@GixxerFoo]

That's a nice cam and it loves some compression, all Wood cams work exceptionally well with compression increases.

[@RJ67.]

I put an EV-46 cam in a 1340 1990 fatboy, with a dyna ignition & coil and a few other tricks

[@GixxerFoo]

Evos love Andrews cams, Andrews sold untold numbers of cams for the Evo. They just worked in those motors.

[@trippontwowheels]

Yes!

[@Chris-gi9ch]

Within a small super wealthy city of Piedmont, Ca in the middle of Oakland, there's a gas station that sells racing gas straight from the pump. However........? Not sure about riding in with a thunderheader? 😄

[@Aikiswfl]

Good video but, I’m assuming you’re talking about static compression not dynamic. The 10.5:1 never actually happens because of valve overlap etc. it’s the dynamic that’s important. Could you expand a little more on those numbers in a video some time. I was taught that a few point either side of 9:1 is the sweet spot for a hog that runs on pump octane of about 91-93

[@GixxerFoo]

That's an excellent point, I was trying to keep it somewhat simple without really diving into static and dynamic. That's a real can of worms I can go on and on about lol.

[@george6036]

Great job as always brother! thank you

[@dafigie]

Im all for hot rodding engines, but there is a dark side to performance mods. If you want your engine to run forever, anything beyond a stage 1 upgrade is going to decrease engine life.

[@tl5108]

Yeah the more power something makes the shorter the life span

[@GixxerFoo]

That's very true, you really have to build the engine from the crank up for reliability. There's guys with quite a bit of miles on street ridden 120R's.

[@mikemastropietro9482]

Can the crankshaft handle the power? What crank would you recommend to up grade? Thank love your videos!!!!!!!!

[@GixxerFoo]

That's a very good question, I would say yes as long as you don't ever lug the engine and take care to be in the right gear. But if you're going to upgrade the crank a Dark Horse Crank is very hard to beat, both in quality and price.

[@JakobKaizen]

Thanks to your video I’m now about to have a .027” MLS Cometic head gasket installed together with the S&S 570 on my 103”. Is this only gonna squish my compression a bit or should I retune with the FP3 and add something to it in order to make it run as good as possible?🤘🏼

[@GixxerFoo]

That should work very nicely! You will still have to retune with that cam and new setup though with the changes made!

[@1957eberhart]

up the compression and then what about the crank?

[@GixxerFoo]

It's about the same as adding power through big bore kits and cams, the cranks fair pretty well unless the bike is just being beat on hard.

[@mose717]

How does higher compression impact engine life? I'm looking at a higher performance build that's still suitable for daily street use.

[@GixxerFoo]

It makes the engine more efficient and if you're not beating on the motor all the time it won't impact the longevity. Now making sure you have compression releases is key, it can lead to starter and component failure in the starting system.

[@TheXcr800dude]

Harder on the starter. Add compression release. As long as you have good high octane gas you will be good. If you can find it use off road 91 plus. It is ehenal free

[@richardcolozzi6425]

Morning Strocker 103 h.d.204 cam recommend after market cam

[@rugershooter5268]

Now wait a second......the reason we use 93 octane is because that 87 causes knocking......it causes knocking because it burns too fast The idea of increased compression is putting the same amount of air and fuel into a smaller space......thus fuel molecules are closer together and will burn faster......more likely to knock Remember the cars, they'd put on turbo chargers, which put more air and fuel into the same space increasing compression, then they'd adjust the ignition timing to take out the knock......smart ones started using 93 and adjusted to that fuel.....that way they could still get max pressure at 20* atdc and complete burn at 70* atdc, which they couldn't quiet achieve using 87 But now you're starting with an engine designed for 93, then increasing compression The crotch rockets running high compression with 93 also have a short stroke in order to get stages of burn in the correct places The short stroke cruiser engines(not as short as crotch rockets) running 9:1 also use 87 to get a faster burn

[@johnraconteur1723]

I may be wrong, but here's what I thought: Octane rating is a reference to basically how stable is the fuel, as in higher octane fuel can sustain higher heat and compression before it self ignites. Higher compression requires higher octane because lower octane fuel will pre-detonate too early in the compression stroke. Higher cylinder pressure and a greater amount of air/fuel mixture results in greater potential energy being released with each detonation. I don't think that the closeness of fuel molecules effects burn as much as you think. What's more important is a finer, more even distribution of fuel in the mixture. Flame front movement is more impacted by the shapes within the combustion chamber and the placement of the spark (or sparks if you have two plugs per jug). tldr; more cylinder pressure and air/fuel mixture means more potential energy released each cycle. Higher octane is stable and can handle the extra pressure without pre detonation.

[@Clutch_Kick187]

My 2010 street glide was a 96 (9.2:1 comp) now built to 103with 10.5:1 with S&S 585 Ez start cams, clutch, intake, & 2into1.. 111hp & 119tq and it doesn't knock even on the hottest of days.. I keep a can of octaninium in my bags to splash some in for if Im running hard with the boys, but never have I heard it knock even on 93.. Hell my Mustang is 12.0:1 Compression from Factory, my last Camaro SS 1LE was 11.5:1 comp, both ran great on 93.. no knock.

[@isaiahgrimm2810]

I have a 2003 dyna low rider anniversary edition that I get about one start attempt before the battery drains and it won’t try to start again .. what could be causing this ?

[@GixxerFoo]

It completely kills the battery? Assuming you have a good battery, you've got some serious amp draw. Without seeing it and assuming the engine turns over freely you might have something going on in the starter and or the solenoid. I would definetely get that tested.

[@rickrondeau.7657]

I has ever been watching your videos on the 107 and compression of 10.5 to 1 got my heads at 10 to 1 planing on going to 10.5 to 1 soon and going use tripple duece woods cam for low end tourque looking for video on installing pistons and heads with torque specks and adjusting pushrods

[@gregfortmayer4535]

I watch all your videos. Thx Question I have a 2017 Breakout i bought woods 777 cams and going to change all parts as you instructed. changing rocker arms to 1.725 roller type, 5.3 injectors, then Going to send heads to Hammer performance to get port and polished . what 4 in big bore kit you recommend for this set up. would like to do this all at once. but what to stay at 10-1 ratio

[@gregfortmayer4535]

I watch all your videos. Thx Question I have a 2017 Breakout i bought woods 777 cams and going to change all parts as you instructed. changing rocker arms to 1.725 roller type, 5.3 injectors, then Going to send heads to Hammer performance to get port and polished . what 4 in big bore kit you recommend for this set up. would like to do this all at once.

[@rickrondeau.7657]

I have a twin cam 96 2008 Dina that I triked I’m putting a 107 kit with 103 calendars bored to 107 yoking water cooled heads that are ported shaved for 10.5 comp woods triple 2 cam what do you think I’ll hav in the end. I watch your videos on you too can I get some feedback thank you Rick

[@hugieflhr03]

Almost every Harley I’ve ever owned has been treated to a nice set of forged Wiseco pistons of 10 to 10.5 to 1.

[@GixxerFoo]

Right on! It makes a huge difference, the factory compression is way too low. Works great for just cruising but it really hold the power potential back.

[@dynarider2380]

So if I wanted to use those gaskets your talking about how would I check valve clearance? Can I do it myself or do I need to take it in?

[@faroeselegionnaire3174]

Have a 2014 Street Bob, can I have changed my exhaust with a V&H two to one pro pipe - I do not want to change original Air Filter

[@GixxerFoo]

Yeah you can go to a two into one, you'll just need to tune it of course but you can keep the original air cleaner. The bike may run a bit rich, I would suggest a K&N air filter stock replacement to help with that though.

[@bigwu100]

All that with a pressed together crank ?

[@GixxerFoo]

Yeah you wanna proceed with caution on those cranks. They are a real pig in a polk, sometime you can get away with it on those cranks and other times total disaster. I always say err on the side of caution and keep it mild unless you're getting a built crank.

[@reclineandride2064]

I went with s&s 585 and weisco 10 1/2 :1 pistons. Dyno 94hp 104 tq on 103 tc

[@GixxerFoo]

That's some nice work! Really good power increase with that compression and cam!

[@reclineandride2064]

@@GixxerFoo what would you suggest for upgrading heads and or throttle body now?

[@trailerparkcryptoking5213]

You need to figure out what’s wrong with your combo! You either have a crappy tune or at very high altitude! Should be making 100+ HP & 110 Tq. Don’t need to spend money on other upgrades until you get what you currently have set up correctly. Did you set up proper Squish distance, 0.030”? You can get more HP with stock flat top pistons and proper squish than your domed Wiseco.

[@rickrondeau.7657]

And another thing what keeping it cool with the 107 inch Moter don’t like my legs getting burned

[@craigburbery2551]

Happy life happy bike

[@GixxerFoo]

It may not be the solution to all problems but it helps!

[@randylucas2458]

The 110s had to keep the compression low because the crankshaft couldn't handle the pressure

[@GixxerFoo]

That's a good point! Reliability and warranty concerns really played a part!

[@frankhicks8443]

Just had a 510 cam installed with gear drive, cam plate, oil pump, lifters and push rods but there is some noise i noticed from top end. What should I check? Should I check push rod adjustment and timing? But was wondering what the compression should be with the parts I had installed?

[@GixxerFoo]

Pushrod adjustment and timing would be a good place to start, compression shouldn't of changed much if any. What kind of noise is it? Mechanical noise or maybe something like detonation?

[@frankhicks8443]

Sounds like maybe rockers not very noticeable to anyone but me. But I just hear a difference in the motor noise. Do you think it could be the gear drive? Going to buy oil pressure gauge to see if its consistent or if it flutters. Is there any websites you recommend for parts?

[@chalibanec1]

Mate,i feel like we building bike together. Nice timing 👍🏻

[@timothygadbois7851]

He's the reason mine was as built the way it is

[@GixxerFoo]

That's awesome! What ratio are you looking at running?

[@GixxerFoo]

How much compression did you end up going with?

[@chalibanec1]

@@GixxerFoo me?:)))) I'm chef, I learn from u(and Kevin Baxter) but all this topics I discuss with my tuner,my session will be next week. Thanks to your videos I got rough idea what I want.

[@wtsherman9378]

I agree, Screamin' Eagle parts should installed as original parts from the manufacturer... and then thrown away when you upgrade the bike. There are much better parts out there than Screamin' Eagle.

[@GixxerFoo]

Screamin Eagle is an upgrade over stock but no comparison to after marked parts!

[@johnsb1550]

Quick question, I have 2 2002 FXDWG'S and would like to ask you a few questions about them, just wondering the best way we could talk

[@GixxerFoo]

Sure I am on Facebook and Instagram, I can message back and forth with you there!

[@ronetuley]

Great information to know 👍 keep the videos coming brother and ride safe my friend.🇺🇸🇺🇸🇺🇸

[@GixxerFoo]

Thanks, you too!

[@L8R2YA]

I got at 2017 fxdb getting MR103s put in thinking of going 10.5 comp while I’m at it, am I going to have valve clearance issues trying to achieve this by just shaving heads ?

[@justin.s9783]

have you thought of doing a supercharger / turbo charger guide ? i know they are pricey, but if one really wants to get into engine mods lol. good vid

[@GixxerFoo]

Actually a bolt on turbo is about the same price as building an entire crank up. I am actually working on a video about turbo chargers for Harleys and what the pros and cons are.

[@justin.s9783]

@@GixxerFoo ya they are very expensive . at least the ones i priced. looking forward to seeing what you came up with

[@thewheel2023]

So how much compression, requires compression releases In a T.C. 88?

[@GixxerFoo]

88's were stock at about 9.0:1, generally about 10.0:1 is a good rule of thumb to go with.

[@joehuro2906]

Just bought a set of KB 411 10.5:1 pistons sending heads in for Port n valve job. I already have Chris rocket 574 cams. Cams state up to 10.1:1 comp. .Do you think the 411's will work properly with the extra comp. I have a fxs blakline 103ho

[@GixxerFoo]

Maybe with some very careful tuning but that's a lot of compression over what those cams support. Depending what head porting you're doing that really get to more than what the cams can support.

[@joehuro2906]

@@GixxerFoo after reading your reply I got to wondering should I continue. Well I contacted Chris Rivas shop . They said I would be within the limits and should produce lots of torq. But 11.1 comp. Is a no go. Thank you for the idea of adding comp. You have great information I will continue to watch. Have a blessed day

[@jamessouthworth1699]

I wonder how the twin cam 88 crankshaft holds up to higher compression...

[@candersson7419]

Just fine so far although I have a 99 with the Timken bearings. 95 cui ported heads andrew 50 and 10:25-1 compression

[@jamessouthworth1699]

@@candersson7419 you've got them when they still had the good bearings mine is an 03

[@fern0031]

@@jamessouthworth1699 I have a 2000. Is that still using the good bearings? What year did they switch? Thanks

[@GixxerFoo]

They do run a whole lot better, there's really not any issue unless you're really beating on the motor. But that's with anything, if you ride it hard it will reduce the life expectancy.

[@jamessouthworth1699]

@@fern0031 The first year they put in the cheap bearings was 2003. Yours is good

[@markdandersen]

Bro… can tw222 handle higher compression?

[@GixxerFoo]

They sure can, they will actually run pretty damn good with some more compression.

[@RGD1982]

I have a 06 road glide with a 05 engine and I don't know what pistons or compression ratio it has but if I run 93 octane it runs like crap If I put 110 octane in it runs great. It has a very mild tune and puts out 97ft lbs and 89hp and it's a 88c.i. any ideas ?

[@GixxerFoo]

If it's making that kind of power someone has done some engine work at some point. It's likely got some high compression pistons, cam and maybe a bore. Really no way to know for sure other than tear the motor down and see what's inside and do some measuring. You could run a bore scope into the spark plug holes and look at the pistons, see if they are domed or have a flat top.

[@thatbuelldude189]

My buells new motor will be pushing the limits 11 to 1 comp ratio Nallin stage 3 heads N8 cams Hrs 42 carb And a full forcewinder induction system plus exhaust

[@GixxerFoo]

Damn N8?! Talk about lift!

[@thatbuelldude189]

@@GixxerFoo he went balls out Motor was in a cyclone drag bike Went in the low 9s

[@tomrohn8607]

Would Andrew's ev-27 cam work ok with 10.5 compression?...

[@tomrohn8607]

This is Evo

[@barrybray7354]

Hey dude no luck yet on fixing old bike or having cash to buy knew but I said I hit your like every time I saw you had dropped video so just keeping my word hope you an your are good B.

[@GixxerFoo]

I appreciate you watching! I hope you can get bike going soon!

[@barrybray7354]

@@GixxerFoo im not watching I'm hitting like button an going to to none Harley stuff don't want to get depressed. Just wish you were close I know I could talk you into helping me. But that another story have great day my friend.

[@randylucas2458]

I have noticed that you have the exact same accent as Mike Nesmith from the Monkees he was also from Texas I wonder if you guys are from the same town

[@GixxerFoo]

Lol I am in Oklahoma so pretty close!

[@randylucas2458]

@@GixxerFoo interesting cuz you guys have the exact same intonations I actually went listen to him talking and interview just to prove it to myself my grandma's buried up there at the rez in Enid

[@robbyclark6915]

Hey, my buddies think a new breather and exhaust IS hopping up your Harley!🤷🏻‍♂️

[@Frankfoot986]

That’s basically making it run how it should come from the factory by adding air cleaner and exhaust

[@GixxerFoo]

No doubt about that!

[@GixxerFoo]

Lol it's the first step at least!

[@raystrickland344]

How would you no. I haven't seen you fix anything yet!

[@thechiefengineer5886]

Im getting 10.25-1 pistons in my 103 with ported heads ... after this video i dont know if my starter can take it

[@GixxerFoo]

If you've got some compression releases you'll be in good shape, a high torque starter never hurts though.

[@thechiefengineer5886]

@@GixxerFoo think the comperssion releases will be as expensive as a high tq starter

[@thechiefengineer5886]

Just remembered that the 103 does have ACR 🤦‍♂️ Its my 96 that does not have it ...

[@GixxerFoo]

👍 you said 103 but l wasn't sure if that was a factory 103 or conversion. You'll be good to go then with those pistons.

[@thechiefengineer5886]

@@GixxerFoo yeah thats was my bad , thank you and keep up the great work 👍👍

[@UncleRobsGarage]

I had to get rid of my harley, because I can't maintain, so now I've got a 900 Vulcan,and the cops love it .

[@RGHD912]

Did a 117” S&S big bore kit on my twin cam 103, what would be the best cam for this set up. Bigger throttle body, S&S oil pump, S&S 585 cams 2 into 1 pipe etc.

[@GixxerFoo]

That 585 S&S cam is hard to beat, it's one of their most popular cams and for good reason!

[@RGHD912]

@@GixxerFoo was thinking s&s 620, your thoughts?

[@alcapone1976]

Do you ever work on anything??

[@GixxerFoo]

Quite a bit actually, filming is a real pain when your strapped for time trying to get a job done.

[@trailerparkcryptoking5213]

Who makes a good 103 TC lightweight piston with 10.5:1 CR?

[@goodboyringo9716]

It's not a 103 piston , it's a 95" piston . Piston size & stroke make 103 .

[@trailerparkcryptoking5213]

@@goodboyringo9716 you don’t comprehend plain English?

[@davidharrell8890]

I thought you’d want lower compression if adding a turbo.

[@GixxerFoo]

You for sure need lower compression for a turbo, but then again it depends how much boost you plan on running too.

[@davidharrell8890]

@@GixxerFoo Got it, Thank You Gixxer Foo. 👍👍

[@genekelley7579]

🛑🛑 Great Video Gix👍💯 Great Content as Usual😀👍

[@GixxerFoo]

Thank you I appreciate it!

[@genekelley7579]

@@GixxerFoo You are “The Book of Knowledge”....😀💯👍

[@beercanbrian1880]

77K and change on my 2002 stage 1 RKC. Still getting me down the road problem free like the day I drove it off the lot. There's no free lunch. I'm guessing as HP and torque go up, engine life goes down.

[@GixxerFoo]

It's possible reliability can suffer, but if the engine has all the supporting components reliability can be maintained.

[@vtwinpower1903]

NO REPLACMENT FOR DISPLACEMENT, GO BIG OR GO HOME S&S HOP UP UR HARLEY!...😎 my twin cam 88 is now FULLY BUILT106 stroker on NITROUS! chain drive airshifter,🤣 LETS PLAY!.✌ 170hp n climbing! SHES A HUGE WHEELIE MACHINE!!. N I RUN A SLICK ON HER FOR HOOK UP!

[@GixxerFoo]

Damn how much nitrous are feeding it?!

[@goodboyringo9716]

Screaming mouse parts , not screaming eagle parts .

[@walkerforsyth6221]

Clicked on video to see Harley service information for customers... ..but as I watched I began to miss my '04 blue and white GSXR 1000. damn.. why did I sell that!

[@GixxerFoo]

I had an 03 and l miss the crap out it. There's a guy that rides a silver 03 that's like brand new around town here. I have stared at the bike for years, never been able to catch him though.