.308 Cam & Dual Valve Springs ~ The Road To Horsepower Ep 7

On today's episode of The Road to Horsepower, we install a .308 cam and dual 40lbs valve springs. We have to use a special tool to cut the spring pockets out in the head for the proper valve geometry. Then failure occurs. Stay tuned to the next episode where we fix the problems and make even more horsepower!!!
Parts & Products Used In This Video
.308 Cam - bit.ly/3NfvjmC
Dual Valve Springs - bit.ly/3RJtZff
Billet Retainers (Dual Valve Springs) - bit.ly/41aqrGA
Billet Retainers (Single Valve Springs ) - bit.ly/3GOhmei
Stainless Valve Kit - bit.ly/3aQEWKw
Hot .265 Cam - bit.ly/2WoQA3V
Fire .265 Cam - bit.ly/3HwY9MH
.010 Head Gasket - bit.ly/3WzwTUI
Autolite 3910X Spark Plug - bit.ly/3qCKjCk
TM24 Flat Slide Carb - bit.ly/3ZtvRMB
TM24 Flat Slide Carb Kit - bit.ly/31TsUWm
VM22 Clone Carb - bit.ly/3X6cdVc
VM22 Clone Carb Kit - bit.ly/37KXRzZ
VM22 Genuine Carb - bit.ly/3J4D1kL
VM22 Genuine Carb Kit - bit.ly/3iHd1AP
Stock Carb Performance Kit - bit.ly/3kZ96wr
18Lbs Valve Springs - bit.ly/2QPD34e
26Lbs Valve Springs - bit.ly/2z84MXp
36Lbs Valve Springs - bit.ly/40W5yzt
Throttle Top Plate - bit.ly/3buiBOs
Billet Flywheel - bit.ly/2vDOft1
Slipstream Flywheel - bit.ly/3C4kFM9
Stage 2 Kit - bit.ly/3HdeCGE
Air Filter & Jet - bit.ly/3kZ96wr
Header - bit.ly/3Wx2bf4
Build Your Own Header Kit - bit.ly/2NDPdM9
3 Disc Racing Clutch - bit.ly/2HXseYN
Juggernaut CVT Pulley - bit.ly/3aAl355
Mega Moto Mini Bike Kit - bit.ly/3aPEfM6
Magnetic Oil Dipstick - bit.ly/3Ylg7do
MSD Coil - bit.ly/3wn8uX2
Amsoil - bit.ly/3TWtrmM
Merch & Events - bit.ly/33YbmtO
Check Out Go Power Sports for all your Go kart needs! bit.ly/2viX9vP
Parts & Tools used on the channel - amazon.com/shop/redbeardsgarage
Quantum Machinery- Siegmund Welding Table - bit.ly/36PHm6G
- Nargesa CC60 Bender - bit.ly/2xWDVxj
Prime Weld Tig 225x - amzn.to/3L4U3MG
Prime Weld MIG180- amzn.to/3KVUPvn
Amsoil Affiliate - bit.ly/3TWtrmM
Benchmark Abrasives (cut-off wheels, flap discs..) bit.ly/2SENg4f save 10% REDBEARD10
Want to donate without the commitment? - paypal.me/redbeardsgarage
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Instrumentals by Chuki Beats - / chukibeats
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*********Disclaimer*********
Please do not try to re-enact or recreate anything you see in these videos. We are trained professionals. Red Beards Garage does not take any responsibility for injury's created by doing so.
#RBGKarts #RedBeardsGarage

[@honeybadgeractual5734]

We want more road to HP videos. Hope to see some soon bro.

[@ol-man-duffyj688]

What you did right: made this video for us. What you doing wrong: Making us wait more than SIX MONTHS for the next video. LETS GOOOOO baby!!!!🎉🎉🎉 🚀 🚀 🚀

[@paulposton393]

Most people would leave out any mistakes made, I like the honesty

[@davidholcomb9961]

This is the stuff that makes me really get excited about my build! I'm waiting for my new bike from Go power Sports and it should be here in a week! I'm 58 years old and couldn't be more excited than to get back into gear head work! Awesome videos Red Beard!

[@timb6763]

I was just telling my buddy this is like building old school muscle cars without it costing you a second mortgage, and it doesn't require a bunch of specialized tools or electronics.

[@jharlowrose1]

What happened to the rest of the builds lol. Damn it, I got hooked after the first two. Bring this one back please

[@mandrew20111]

That’s what I am saying!

[@Parents_of_Twins]

That beard is worth at least 2hp if not more.

[@Earth11111]

4.5

[@benpeter4959]

I've seen smaller beards gain 2 hp. His is on a whole new level.

[@NubsWithGuns]

That beard doubles as a supercharger.

[@groskreutzzdsinn17]

It's been honed for maximum performance

[@FreeRunMonster802]

We need a cam shootout, similar to the carb video. Stockish head and stock rocker ratio, stock cam vs mod 2, hot 265, fire 265, 308? Would covers the bases for most builds.

[@jimcornish242]

I liked the fact that you've shown some of the issues that we can run into when we go breathing on these little engines...it's not all biscuits and gravy..there can and will be failures at times

[@ColinandDaniel]

I watched all episodes today no this coming out the same day is perfect

[@jdoe9518]

For checking installed height snap gauges or inside calipers work well. Or measure valve tip to spring seat ie. 1.250" then measure valve tip valve retainer ie. .175" then add thickness of retainer ie. .075" = 1.00" installed height For repairing ports or casting the best product is called Z Spar. It's a 2 part marine epoxy. It's the only thing to use for engines that will survive. If you plan slip jointing the exhaust it is critical that the O2 sensor be fitted before the join. The slip joint will draw in air that will give false lean mixture readings. A properly designed (small chamber, correct valve/rocker geometry, correct porting and piston) Hemi head would out flow, out rev and produce more torque and horsepower than any bath tub flat valve head.

[@Parents_of_Twins]

Great video. I think putting some rubber on your motor mounts and then using a spring is an excellent idea and should cure your issue with the exhaust breaking. I really love this series. I like that you're only changing one thing at a time and then showing how much a difference it makes on the dyno.

[@newbornlog2789]

A small sprinkle of closely cropped bright red beard hair and a drop of beard oil.

[@GeorgiaRidgerunner]

motor mounts will cause chain throw especially on the out of balance predator engines

[@gregswafford9839]

Love to see that non-hemi swap head on this build before balancing the rotating assembly. I feel your at about the max for a normal back yard build with this setup the way it is and seeing a non hemi head (ported and non ported) put on the dyno would be great for most. Love the series and the content it is bringing forward for us to compare. Appreciate the time and look forward to the next video.

[@cwgreen1938]

I really enjoyed this dyno run and the fix that you are going to make to the exhaust on the dyno. love all your videos. I used to think Cars & Cameras was the best to watch but not any more, that's why I became a pateron to RBG.

[@FangOfTruth]

I knew some guys used JBWeld in V8 Ford cylinder that had a crack. Held up just fine. The vibrations of single cylinder engines will show any weakness of material. I don’t blame your work or JBWeld for this. Keep up the good work.

[@SNELLERIZED]

I was really hoping to see the 308 graph overlaid over the 265 graph.

[@baldbutton1983]

Same. I’m curious as to what the power curve looks like. Does the .265 make more power in the lower RPMs? I have the exact same setup that he’s building, but when I switched to a .308 from the .265, my kart went from 8000 RPMs to 7500. I’m wondering if my go kart is too heavy to get up to the 8400 RPM that the .308 is rated for

[@burnttoast5407]

@@baldbutton1983 if you didnt do valve springs like this build you might have valve float

[@theinsaneshecklador6598]

That would be convenient. However if you pause the older ported head vid at 5:27 and look at the left you can get a comparison with 14:05 on this vid. On the old vid it shows 11.43 HP and 8.74 TQ at 4,000 RPM and in this new one it is 11.01 8.43. You can look at all the 100 RPM increments if you have time Looking at the line graphs I'm guessing as the RPMs get lower than 4,000 it probably gets a bit inaccurate due to the throttle roll in. Similar to the lower end of a lot of car dynos.

[@pablojanski.2559]

only other issue I see with machining the spring pocket that deep, is material thickness under the spring. Sping pressure is most likey going to punch those pockets out in short time. I've seen it happen with automotive cylinder heads. And I do a LOT of auto racing cylinder heads.

[@garykarenmcgruther6386]

bingo, i would opt for longer valves and mill the pedestal's down and drill and tap for Gage motorsports stud mount hemi 1.2 Roller rocker ratio rockers. full adjustability then.

[@lonniebartels7237]

I also forgot one other thing I'm going to luminum heads I found out that the aluminum weld sticks that harbor freight sales works really good at helping them fill in holes or cracks on aluminum heads and and hold a lot better than any epoxy will

[@aaronyoung8132]

Id love to see a shootout on the dyno between the 308 the 310 and the mod1 from dyno cams, all on that engine when its put back togeather

[@anthonyrollins9825]

your my fav cueball with a beard bruh , keep it real.

[@rcclassiccrawlers4368]

Great idea about exhaust fix. I’m impressed with the numbers on that build. 19 horse…. Damn!!! 👏👏

[@williamcummings6562]

You’re doing really good with the Dino . Fun to see what can be done with it!

[@shk2564]

Red Beard I have to say that I have been passing over your videos for a long time because I am already subscribed to several channels that are doing the same type of videos but I watched the video where you helped out Jose and I was impressed by you and your integrity! I subscribed and watched the next two videos that you had posted and you continue to impress me. I love that you are a Christian but you don’t push it and instead you just display it in your character. I do like the sharing of scripture on screen when it is appropriate. It’s a nice touch! But I am really happy that I found you on the last day of 2023 and I was able to binge watch the Road To Horsepower series! What a way to see out the year! After this series I am going to spend the rest of the day/year enjoying the fun content of builds and blasting around! Happy New Year to you and your family and I pray that 2024 will be full of blessings and prosperity! 🙏🤗❤️

[@lonniebartels7237]

I do some regular engine building and sometimes on some of the heads I will have the machine shop meal the pedestals for the rockers so I can put a different set of rockers on it to allow me to adjust for travel and height you might want to think about that on those who had you can actually Mill those pedestals down and redo them to where you can put a different style of rocker on it it might cost you a little bit more but I think you could probably get a lot more horsepower out of hemi head with different rockers for ratio and lift height especially if you want something with a Lillian grunt or a high RPM horsepower

[@carsonpeterman4564]

You should do an episode where you switch to methonal and see how much of a change it makes

[@RedBeardsGarage]

We are planning on doing a fuel video soon

[@mandrew20111]

@@RedBeardsGaragehow soon? It’s been a year 😆 loving the vids! Just got into mini bikes yesterday and looking at building a 212. These videos have been a big help! BRING THEM BACK!

[@NsXy]

This is really awesome thank you for this series. I just started watching the whole thing today and I was surprised to see that you just posted the latest video three days ago. Can’t wait for the next one. I hope at the end you turbo charge it.

[@SportbikerNZ]

Good video. Always interesting to see the power changes. Keep up the good work.

[@jaybird0000000]

great video red i just keep learning love the way you explain things keep up the good work

[@seanb250]

I use Zsparr epoxy for intake ports, the area needs to be burr rough and extremely clean before applying it, also having heat in the head helps to keep it bonded while it cures. 12.5 on the fuel ratio is definitely correct for wide open throttle power on unleaded fuel, anyone saying 14 is wrong 100% 👍 Great series that I look forward to watching every episode, cheers from Australia 🇦🇺

[@Charles-bj7qu]

I have a 400 2 stroke and that is how the exhaust is set up. Two curved flanges and four sets of springs. It is a beast. Love your show.

[@jimholesaw6597]

I think it would be cool to see how much power gain can be made with all stock parts on a 212cc. Bored stock carb, bored stock jet, lightening the piston, shaving the head, port job, ising stock rocker to gain ratio. all the trick stuff.

[@RedBeardsGarage]

We will try and do that soon

[@rong4189]

On cars with aluminum heads, you always run a steel spring cup to protect the head from the spring digging into the aluminum, but in this case, you REALLY don’t have the room lol. Having to mill that much for less than .400 lift just sounds excessive. There’s gotta be a more suitable spring for this. Meaning I think that spring was brought to market too soon.

[@jameswade2002]

I used Magnum Steel on a 6p 13B rotary and it worked for a year. Might be fine now, but I haven't tried to start that engine in over a decade. Y'all don't want a FC3S chassis do ya? Garage kept hard top, all the parts, and a ported 13B.

[@SB-fe4gt]

Leaner will give you more horsepower but I wouldn't go below about 13:1 just to ensure you don't burn valves in the long run. Awesome series, Thank You!

[@eriks87cam702]

When your worried about peak hp your not worried about burning the valves … they do the same in nhra on the top fuel dragsters …

[@icelover3]

@@eriks87cam702 The difference is people aren't building these engines for a single run; they want their engines to last.

[@Dlokey4315]

Hey Red,always a nice informative show as always.

[@warniedaniel9867]

Maybe a braided flex exhaust piece, might have to use reducers to make existing work but the flex pipe should work. I’ve seen them on the shelf at oriellys

[@dylanpassmore8186]

“I’m doing thing just like you guys” meanwhile I’m in the garage with 3 screwdrivers, a ratchet and almost a socket set🤣🤣

[@markyoung9964]

that's where we all started!

[@classyreaper5384]

We all get it done ✅

[@200shotramhemi4]

Dyno series is Great, Keep up the awesome work

[@JNC1973]

I have a non hemi head on my bike but I actually bought the Go Power Sports Stage 4 Race Head that came shipped to me with those Dual 40 pound Springs already installed which eliminated any need for cutting. Just bolted and off i went. Made a big difference in power you could feel. I got one of those little gadgets that you wrap the wire around the sparkplug wire a few times and it tell you your RPMs and for me while i was riding it got into the 9000s. I was like holy crap ! I knew this thing felt really powerful but i didn't know i was over 9000 rpm. That's if it is acurate i have no idea lol.

[@stevenboswell4524]

Best series on the internet!

[@GILSJOURNEY]

I want to thank you for the videos. I have built my non hemi predator 212 all the way through this final video. It is running very strong. Not sure of the HP or top speed yet but it hit 64 mph with ease wanted more but I ran out of real-estate.

[@Dirtdog7680]

Good work Greg and yes Mark is a big help and great person. I would recommend A-B Moroso epoxy works great with gas, methanol or Nitromethane and does great on exhaust ports where extreme temps are.

[@burnsbuilt2153]

Your right, 12.5 to 13 afr TYPICALLY makes best power on NA applications

[@kriskersey9927]

I'd suggest a flex pipe in that area or a silicone coupler.

[@davekulman8195]

What you really need is a flow bench for small engines then you can more accurately select a cam and spring's don't have to be as strong as everyone thinks you only need more spring pressure when valve float is present besides stock springs I don't think you guys have floated a valve yet

[@johnpilagonia5238]

Where did you get the spring pocket cutter?

[@jimilesaint]

Great series Red Beard… no BS, just facts

[@wrenchg3954]

yo big red, do some research and reading into, the Stochiometric ratio. anything that burns fossil fuels on earth will make peak performance from fuel energy the closer you can get to this ratio. keep up the awsomeness

[@michaelcooper10]

Flat torque curve and the horsepower kept pulling. Bring on the beast.

[@justinvanburen8259]

Another great video!!

[@jimhertel5125]

The jb weld didn’t fail the spring pocket is probably flexing like crazy being that thin

[@flinchbacher]

I watch all your videos! Been building V8's for some years - but this really looked like fun. Didn't think I would be using my calipers.... but I do. First one was a Predator Ghost and then tore it all apart to make real HP following your ideas. So I always come here to learn more! I did run across a You tube tech video by ARC and they mentioned the gauge you are looking for - BSP. 815 Installed Height Guage - by Larry Jones Motorsports Hope this is what your looking for

[@Texasrelics]

What can I do if my 150cc flywheel timing mark is off from the piston being at tdc.

[@Dennisthemenace40]

Really impressive work 👍👍

[@seamushassard4770]

It would be cool for you to do a video or maybe even a series on engine longevity relative to performance level, and maybe there are modifications that could be explored to improve longevity in modified engines?

[@isaaccrall5360]

Where’s episode 8? I need it!! I love your videos man I’m collecting parts following “The Road To Horse Power” I’m ready to finish it up..let’s finish this engine 😎🤟🏼

[@Spazz1892]

Please continue with this series

[@CODOutdoors]

JB weld said, Ejecto Seato Cuz! Any plans for a meet up in the near future?

[@anthonyreddy2834]

Very nice episode, why cut the spring pockets if you still need to take it too a mill?

[@RedBeardsGarage]

I was basically showing how the tool worked.

[@cliffpalermo]

That glitter is hp abrasive freeing up some ponies by polishing the bearings for less drag:)

[@cedhome7945]

As a random thought what about a mini engine drag race series it will be affordable and will help push engine design and development faster for all.maybe start with under 230cc and under 500cc classes with limited add ons for the first season (no turbo/supercharger or nitros )come on people you know you want to...👍

[@poolhuslter]

Great work brother! Project Farm did a spark plug video that showed a pulstar spark plug gave a predator 212 almost 1hp boost. I wonder what boost, if any, you could gain from a pulstar spark plug. Also really wish we could run your MSD coil. It's too beefy 😆 love your content

[@omarcastillejos719]

I like the patron sign 😅

[@Just-A-Guy-Learning]

When you port a carburated head you need to make the surface rough. Fuel injection heads get smooth surface. Carb heads need a rough surface. The rough surface helps atomize the fuel. You open it to flow more air but allow the rough surface to do what its intended to do. Even if you take a fine tip on your dremel and dimple the area it will atomize the fuel better for a more efficient burn.

[@icelover3]

I'd love to see you guys try out a billet cylinder head.

[@WyFoster]

Looks like it wants a little more valve spring and a little more rpm!

[@tuyo_adventures.2185]

adding parts and make the sponsor rich

[@artbycapone2710]

You mentioned nitrous in the beginning…you dirty tease. 🤣🤣 Anywho, when can I send my Subaru Robin engines to you to get some numbers, huh? Got an EX17 in the works and an EX21 about to go under the knife…

[@smsservicesall]

This is going to be spicy 🔥

[@FrettJ64]

Its known that the 308 makes big power. Everyone makes the mistake of buying the hot 265, lol. But the 308 is best with a quality clutch, using a 308 with a cvt/ juggernaut driver leaves alot on the table. Maybe the stage1-stage 3 juggernaut tuner kit will help with that.

[@chadmills5400]

Don't be modest. You hit the big time now. You are a professional!

[@scottdecker4361]

You were talking about measuring for spring height and I thought about a dial caliper it has a depth gauge on the back side should work

[@davidowen888]

Little JB Weld in duh gravies 😅 krunchy 😂☮️

[@K_M_M_G]

Before/After filter directly on carb vs. 12"-6" tube with filter? Lets see the mid-range bump up

[@Skiridr22]

The engine still looks great

[@zenzeywyd]

Need new road to hp videos I just watched every single one at 2 am

[@RedBeardsGarage]

Haha! Thanks!

[@zenzeywyd]

@@RedBeardsGarage thank you bro helps me alot

[@donaldhalls2189]

What if you put extra support more at the end of the pipe,? what about the exhaust connection on a cat, round flange into a socket joint with springs on the bolt's to the flange?thanks for sharing, all the best to you and your loved ones

[@lsj624]

Ya gotta dyno a 301cc. We deserve the numbers. Thanks.

[@Buckuporbackoff]

Dude I knew you would do my nitrous idea lol I wanna know!

[@loyd5074]

I like the vids on this

[@suarvemarv]

On a Hemi never cut the intake pocket deeper, only wider for this exact reason.. The exhaust can be cut deeper no problem. For lift over .310 on a Hemi you need the +.150 or +.230" valves.

[@kidddogbites]

Iv always wondered what a marine cam would do for tq.

[@jeffreyodachowski6247]

Whens the next video with this engine? Can't wait!

[@dbaker3264]

At the point with Hemi head, that once you need to break out the tig welder to correct the hole in the intake runner from milling it, may as well tig up the head to take it down in CC as well. Or, come up with another solution for a head if someone can not tig and mill. Also, with squish on the motor has not been give, so would be a good time to shave the block to bring squish down to the .030" point as well. With smaller CC in the head, tighter squish, will be rasing compression to gain more HP as well.

[@stanleyshults6427]

Also Tim has single springs28lbsinstalled height goes to 32+off nose ,mine runs grt,,9200 rpm,s,,,luv that sound it has!!!!!

[@matthewmanuel8655]

Great series! Have you ever messed with an EFI system on these engines?

[@Powercat46]

I was wondering if there would be any advantage to adding bronze bushings to the cam sockets in the block & sidecover for the cam to spin inside? With the high rpm and and bigger valve spring pressure, just wondering if you have ever seen any galling or wear in those pockets?

[@anthonyrollins9825]

At what lift do you start running into issues with the hemi engines ? asking for info when using ratio rockers.

[@baldbutton1983]

I have the same build as in the video. When I went from a .265 cam to the .308 my coils started to bind. I had to cut the pockets. I think .265 fit perfectly on a hemi head, but you may be able to squeeze in a .275, at most, without binding

[@normbeck20]

Great vid, any particular reason you bypassed the .275 cam ? I'm interested to know if the 26lb springs will still be cool on that lift and how much more hp it would make ovr the .265, appreciate you doing these videos for everyone to learn without just guessing, I've learned a bunch 👍

[@jeremy8942]

I'd be interested to see what a variable timing CDI would do for the torque curve.

[@ephenj]

It's impressive what does happen when you run a CDI on them they sound totally different almost like it's never missing an ignition and it totally smooths the curve out from what I have seen. I just dislike the idea of having to run an external power source but if you want ever bit of HP. To me someone needs to figure out a way to let the motor hold more oil somehow. I think it would help them live a lot longer lol.

[@garykarenmcgruther6386]

BigStuff3 makes a stand alone ecu for these but its high priced and the adjustability of timing and anything else including adding EFI if you want, but like you said, it requires an outside power source.

[@jeremyoshea7941]

I’m a fellow redhead and a newcomer to your channel thank you for all the education and your time I gotta ask maybe I shouldn’t have you ever got that beard cought in anything I’m not jinxing you of course. I’m just jealous I get ingrown hairs on my face.

[@garyclarke534]

can't wait till you get to 420 HF

[@Sonos45]

With a dyno at you disposal. Any discussion about air fuel ratios would be good content.

[@ReverendBow]

Man, nice gains.... That cam is pretty impressive, but the spring pocket cutting makes me wonder if it's really worth the trouble on a hemi

[@FrettJ64]

Spring pockets will need cut for 32lb or more on a non hemi head as well.

[@nickbrown7749]

I’d like to see one with an intake length comparison. Like the standard length billet that comes in most kits vs like 2 or even 3 of them together.

[@kylesyx8432]

Great information in these videos ! Quick question why is it when I’m running a vm carb while riding if I hit a bump the engine wants to cuts out. Running a Pz carb in it now and it doesn’t?

[@stanleyshults6427]

Single mushroom springs,Isky cams,ask for Tim!!!

[@brentwinkelman1990]

I think there should be a road to free horsepower series on the predator 212. Free mods everyone can do for just time or very little money. Gutted stock exhaust, gutted/no filter air box, diff plug gaps, stock fan vs small fan/clipped fan. Different degree keys. All the budget options. Brent

[@darrellnichter9894]

calipers and a dial gauge would do your valves...with a lot of math involved. Works in my mind..I think!

[@caseywhite8969]

6" steel rule works for measuring spring height.

[@kellyrenzi9560]

😂😂😂😂😂 That was kool ur awesome man 🤘😎👍.