Porting A 450 Head, Dyno Teaser

Some Inside Secrets to our Porting Process for KTM, Husky, Gas Gas 450 Heads
Check back for an in depth look at the dyno process of this bike and pipe testing

[@driftingsm]

I’m glad I stumbled on this video, 2hrs later I think I have watched all the relevant videos. Great info, and lots of it!, and thanks for taking the time to reply (you have answered many of my questions). Pity we are opposite ends of the world, otherwise my head was going to be in your hands already, although… the wold is a small place after all. G’day from down under.

[@torevenheim9607]

Mad power !!

[@MrMightyGuy]

Can you do a shock video like your fork video you did for the kyb please I learned so much!

[@HPRaceDevelopment]

working on it although probably not a full how to.

[@jbaker8871]

Great video bro. Most won’t share porting knowledge. I didn’t know that power was possible. I was thinking about buying a Kx 500 as that was my favorite bike over the years but I miss out on newer suspension. Would you recommend a 500 over a 450? I know it’s subjective but would appreciate your 2 ¢. I’m 260lbs. I raced 250s when I was younger. Rode a few 450s but never felt the power the 500s made. Desert riding now. I’m really thinking I want my 500.

[@Pereke69]

you crazy if think that a 500 has more power than a 450

[@garrett3234]

@@Pereke69500 would probably have a better power to weight especially stock vs stock

[@lanwickum]

I am 280, rode with a friend that is also 280. Had my 501 and 4 different 450s. We both feel much better pull on the 501. Riding dunes and hills. All the external power stuff done to it. My son and nephew don't feel it. They are around 180. My '22 FE501 is a Cadillac of dirt bikes. Also have a '23 CRF450R I have done some work on to get it where I like it. About $4000 worth. It is more of a race bike. My son does not like my 501 much. Loves his '23 KX450. Just put a 21 engine in it with a 13.5:1 piston and some tuning. Much more like my CR now in power. Watching this because I am putting a 450 ported head on my 501 and a few other things. 1 at a time to see the differences. Ordering parts for this for over a year and finally getting it done.

[@scp8412]

Amazing! What's the cost for a head port /dyno if I have the ECU Vortex already and RP full exhaust setup?

[@HPRaceDevelopment]

If we remove and install head, in the 1500 range OTD

[@kochj0713]

Have you seen the head on a 2022 kx450sr? I was wondering what was done. Smoothed? shined? Thanks

[@HPRaceDevelopment]

Shined - aka nothing. Exhaust and tuning are it's goodies.

[@dontaviousgrace1517]

Where are y’all located?

[@AndryshakGarage]

I have been looking for a small burr bit tool. Do you have a link where you got it?

[@HPRaceDevelopment]

cc specialty has anything you want

[@boru-cnc]

Hello Mate, nice video, but can you explain what is the point of applying epoxy inside a cylinder head ? Can't understand. Thanks

[@HPRaceDevelopment]

To improve flow in running conditions by reshaping the port in a way thats better than as designed. Power isnt about big ports, contrary to the v8 worlds view on it.

[@boru-cnc]

@@HPRaceDevelopment thank you for reply. Oh that’s why, because the angle is too steep on the short side? Do you have any experience with 5 valves yz250f or 450f heads? Old dogs 2003-2013 - I’m thinking how can this head can be improved specially 250 one. I do have access to full 5 axis machines on daily basis but I have to learn what is optimal shape of the ports.

[@HPRaceDevelopment]

@@boru-cnc The 5 v just wont perform as well as a 4v. I havent put much effort into it in years now, but back in the day you could get 5-6 hp more from a 250f yamaha with full mod. The 4v just performs better - but is less long term reliable. Hand porting is the way to develop, cnc is how to replicate…various methods on r&d but flow bench is only a small portion of what works on these high end engines. My best performing heads arent my highest flowing heads, but they cant be bad flowing heads. Valve diameter which is dictated by bore size, cmbined with cam lift determine valve seat throat and that determines port min size. thr marginal gains now being found are tiny little needles in a haystack - rather than simple port size changes or shape - on the modern 250s. They all have relatively excellent shape now

[@boru-cnc]

@@HPRaceDevelopment thank you for the answer. Yeah 5v is more odd shape in the intake, but why do you think 5v is more reliable as I think the valves are smaller so they wears quicker and extra valve spring is causing more resistance for intake camshaft? I will have a look in this head as the idea is to install a billet cnc big bore - I’m going to make it myself - something like a IceCube cylinder. And I was thinking to port it in the same time. It’s an old bike but it’s perfect just for a test to see what results I can end up with, maybe make my own piston as well and check how they will work both together. If good then make more for different bikes. Thanks Dan.

[@HPRaceDevelopment]

@@boru-cnc lower lift, less spring pressure, more valve seating area to valve area to dissapate heat faster, and lighter valve....just more reliable all around

[@mandonini_]

How many HP can I get out of a exc 500 2016 with mods? Love your content

[@HPRaceDevelopment]

not sure! I think the highest ive had on my dyno is around 70 hp but I havent tried to take a 500 to its limits

[@mandonini_]

@@HPRaceDevelopment What mods did that bike have to achieve the 70hp can you remember or take a look please. I appriciate.

[@lanwickum]

Do you know if 501 and 450 pistons are the same? Could I get a high compression 450 piston and put in my 501 with a 450 head?

[@HPRaceDevelopment]

They will interchange but a 450 stock compression piston will make the 501 compression way too high. if you dont know how compression ratio is calculated - google it. Same cc head, but 60cc larger engine (501 is actually 510) requires much smaller piston dome for same compression. If you did a high comp 450 piston in a 500 compression ratio would be 16:1 or so

[@DmenDuroRider]

I need to know how long does the epoxy hold up realistically.

[@HPRaceDevelopment]

Why is this a need to know for you

[@halvorsonmx]

@@HPRaceDevelopment I would assume because he wants to know if you do a cylinder head for him if he should expect a limited lifespan because of the epoxy or will it outlast the valve components.

[@HPRaceDevelopment]

@@halvorsonmx but is it a need to know - or a want to know… It lasts long enough for racers who want competitive advantages. It wont outlast the valve train on a stock engine. It typically lasts longer than competitive racers own their bikes. The cost of doing it via welding and other methods is far too high for what we feel the market tolerates

[@halvorsonmx]

@@HPRaceDevelopment That makes sense. Thanks for the info!

[@babyblow_gee7478]

What fuel was the bike running?

[@HPRaceDevelopment]

mostly pump gas, last pulls on pro6 and c45, was worth about 1 hp

[@dustin9035]

70 HP? Wow, when is it enough? Haha! Your professional opinion, are the factory supercross teams making 70hp? Tomac, Roczen etc?

[@HPRaceDevelopment]

53 off the showroom to 70 was a little bit of a surprise for me as the most power I've built for mx to date was about 62 on a 450 which was too much for it's owner, but for this bike's usage (road race) we needed all we can get! No, pro sx around 60 MAX. Most of the teams are chasing less power and smoother delivery from who we talk to the insights I hear. The best Pro sx 250's on my dyno are in the 45 range (maybe star is 47 ish) and clearly they can turn just about same times.... Outdoors I think 61-62 is about all they can handle as well. At some point you start spinning which aint winning. Great question thx for asking

[@kellybrown2457]

what other mods were done to get 70HP? thats bonkers on a 450

[@HPRaceDevelopment]

@@kellybrown2457 our ecu, fuel, megaphone pipe, cam and some added compression

[@xxgeorgiaboy]

Added compression you mean piston ?

[@frenchonion4595]

​@@xxgeorgiaboypiston and/or head headgasket thickness

[@vaclavhejda5658]

What was the stock power?

[@HPRaceDevelopment]

52

[@k5supreme_85]

I have a 2023 crf 450 and I plan on getting my head ported soon what else could I add to get the that 65-70 HP range

[@HPRaceDevelopment]

probably should start with a 22 model…

[@iprocess1830]

Less music. More bike

[@HPRaceDevelopment]

Thank utube for demonetization of background radio

[@willemdeysel1766]

stupit muciek bro,,,

[@HPRaceDevelopment]

Original sound too loud for the microphone - turns into static. youtube then copyright claimed the music originally selected

[@lerongarnette7480]

What’s yo ig are u location we in Florida