4piston

I have always wanted to share results from when a customer switches to one of our Pro 163 CNC cylinder heads. There have been several challenges with that...
1. It is in pretty large distaste for someone like me to post up Brand X vs Brand Y. We have been in the industry with our competitors for half our lives, and will be for the rest of our lives. Always take the high road.
2. True back to backs with no other changes are hard to come by. There is always SOMETHING else that changed. Most of the real effort we put into back to backs is here on our race engines...and we have to protect our racers and ourselves and can't share the power figures.
3. Back to back results on a 2.7L drag race engine with ITBs and high compression don't really help the guy doing the average street car build.

BUT....there is nothing that says we can't beat up on ourselves a little. We know how good our 156 head is...its one of the best stock valve heads on the market at any price. I'm glad that I can share this 3rd party test. Its the best head vs a really damn good head. It is a pure back to back, 3rd party, and on a small and simple engine with off the shelf parts. Dynojet back to back results, and back to back track results as well.

TEST:
-4 Piston Pro 156 CNC Head vs 4 Piston Pro 163 CNC Head

ENGINE:
-K24, stock sleeve, stock 99mm crank, 87.5mm bore
-Shelf Wiseco Piston, 8cc dome, 52cc chamber, .040 gasket, so around 12.8:1 compression
-Xcessive intake manifold
-Kelford C single lobe camshaft, no vtec and no VTC
-Both heads have a 4 Piston PSI Pro Stock valve spring setup
-Car is a Civic Coupe at 2000 lbs, stock transmission
-Engine Builder and Tuner is Brandon Jefferson of Low Budget Tuning


Pro 156 Results:
309 hp / 208 tq
10.9 @ 125mph

Pro 163 Results:
340 hp / 222 tq
10.55 @ 130mph





Huge thanks to Brandon @ Low Budget for testing stuff quickly and keeping up up to date on all his testing.

Rocket

Physically, what is the difference between the two heads?

4piston

Shape, size, CFM, price...nothing is the same. The 156 is our street head and the 163 is our race head. More work and parts go into it, so it costs more. There are certain setups where the 156 will work better.

For what its worth, I had a guy comment on K20 that he just did a back to back of a Stock Type S vs our Pro 156 on his 12.5:1 2.4L and he picked up 21hp from the stock head on pump gas.

Rocket

More torque everywhere suggests that it flows better at all lifts without much loss of velocity, i.e. increase in port size.

There some other things "I see" from the graph.

4piston

The cool thing about us is that we don't hide much....the flow charts and port sizes are right on our website. We name the K heads by their intake port volume...so 156cc and 163cc. Air speed on both heads is drastically different.

Not sure what you are seeing...but if you use conventional porting theory and wisdom...this probably won't make sense.

Rocket

What is conventional porting theory and wisdom? I forgot to take that class at the JC.

The port volume is only ~4% greater between the two.

If the chart is accurate, there is a flow theory that it supports. Don't want to say explicitly as the bro-scientists will come in acting as if dey knewed it all along.

4piston

Sounds like you know the differences then

Rocket

Getting more torque and power everywhere is not easy to do. Since the heads and cams (lift/duration, valve motion in Nikos world) work better when matched, looks the the match is better.

4piston

This is Nikos right? You signed a couple of your posts as Nikos

Rocket

No, not Nikos. He's a Greek-American and prolly too busy watching Netflix drama series. This is Rocket, Vietnamese-American.

If this was Nikos, there would be a bunch of graphs and quotes from Superflow manuals.

Nikos

Hey Luke, I am not sure why the confusion. Anyway, that is an interesting test. Good thing you are posting it here because if it was me posting a kseries thread on here, the haters would tell me to go to the kseries forum lol

Nikos

Nikos

The confusion came from a user name I made as a joke RMcams .. Racing Machine Cams.. It was a joke and has nothing to do with Rocket. ( I am assuming that is what you are referring to) I do not post on here under any other name.

Anyway, back on track

Uncle Dave

Luke where both of these heads CRV castings or was it the same head reported?

4piston

Yes that is where I got confused. I saw it under the RMcams. My old age kicking in.

Both were in CRV castings, but not the same casting. We can't port one over the other. Both ports fit in the CRV PPA and PPL and the PRB, but that's it.

DDTECH

Good test Luke, solid posting info like that brother. Thanks.

eDm cRxXx

Very good results, and I think the fact that it does not gain absolutely everywhere, but in fact the curve has changed some, shows that the gains are somewhat realistic.

This is the 37mm valve and 50 degree seat right? I would never have thought this head would have gains so far down in the rpm range on such a "low hp" engine.

Very cool.

Do you know how bit the TB is?

EDIT: looks like it's a modified excessive 50mm with a 90mm mustang TB. Probably could gain above 8000rpm with bigger runners?

4piston

I think what shows that its realistic is that the car picked up 1/2 a second and 6 mph in the 1/4 mile. Brandon is always at all the races and has been running low 11s and 10.9s several times in front of everyone. First hit went 10.6 @ 131.

Yes it is our 37-50. We will see how it does on a set of ITBs later. I'm surprised with the results on that manifold as well. It is working better than we anticipated.

Rocket

Exotic

LowBudgetBEe

it has been modified with a mustang 90 mm throttlebody. I still have the 50 mm runner with the velocity stack plate. I'm gonna try a different header, runner and im installing an electric water pump. I will keep everyone updated

LowBudgetBEe

well, I'm still in shock. I had the head on the car for about one month and wasn't in a rush to dyno because I had no idea I could ever make 340 hp on a 87.5 x 99. So while still in shock from Thursday, I went to the track Sunday expecting a 10.80 because I think negative. my first pass was a 10.61@131 followed by a 10.77@129 and ended up with a 10.55@130. 5days later I'm still in shock. I wanna thank 4 piston racing for leading me in the right direction and supplying me with correct parts to do this. ive been thinking about this since Sunday. 131 mph is crazy for a stock crank and stock sleeves.

eDm cRxXx

No doubt it's a lot faster now.

(what I tried to say was that I have seen many "back to back" header, intake, cam (and similar) test where the shape of graph/curve is exactly the same, only higher, and that always makes me skeptical. Dynos are so unpredictable and easy to manipulate.)

But in this case it is obvious that it gained a lot above 5000rpm. And as you say, the race times certainly verifies this.

The fact that it still falls of at 8100rpm with the exact same rate as before led me to think that something is holding it back in the top end (like intake, cams or header).

Thanks for sharing!

What header do you have now?

Very exited to see what the waterpump might do!

Thanks a lot for sharing and keeping us updated, it really means a lot!

Congratulation :D Sounds like a great weekend.

LowBudgetBEe

I have an ssr 4-1 with a megaphone and reverse cone. 1 7/8 primary with no steps. I'm gonna make more power but I'm trying to decide what to do next that won't hurt what I already have.

4piston

Isn't that the truth! You are exactly right.

H.Veras

This would be a very interesting comparison test, I am sure lots of people would like to see how the plenum manifold performs against the ITB'S.

4piston

TR Machine made the switch to Pro 163 and our stage 5 web cam last week and last night they rolled off a 139 mph pass right off the bat....AM Street on Q16 fuel