Taijutsu

Forum: I think most would agree that more comp is better up to the point of detonation/ping/ bad noises. lol
I'm wondering if I am leaving anything simple on the table?

My .060 SB w/TFS heads. Some say 64cc chambers?
The engine appears to be zero deck, .40 gasket, pistons have 2 valve reliefs.

Cam is 218-224 HR w/ 1.6 RRS.
Ign: 32* no ping ever, even when I had to start out in third gear due to trans problem.
Temps are 180 w/dual spals.

I remember reading something that my combo was a 10-1 comp.
Now I am starting to wonder?

Nothing like some extra comp to wake up a motor.

TIA

R

Ibanez540r

"Appears" to be zero deck and 2 valve relief pistons mean nothing really. You have to know exact piston to deck height specs and piston CC to have any idea on actual compression.

mikem350

Typical builds like yours w/64 chambers are nice for street performance. If car runs as you say, forget about actual comp. I would give it some timing at 2 deg increments if you are after some more HP!

If you get pinging, back off...

Taijutsu

I've already been to the dyno.
It likes 32* best!
280 rwhp
315 rwtq
This is w/2.0 RHs
I have 2.5 waiting to go on.

REELAV8R

What is the rest of the set up? Intake, CAI or underhood air, Headers or manifolds, etc. There may be more power on the table that does not include changing compression.
Just feeding cold air will increase cylinder pressure, same effect as adding compression.

Taijutsu

No CAI, or headers. AG w/Demon, drop base w/K&N
2.25 duals, H-pipe stock cheap mufflers.
Nothing fancy.

I'm thinking that a half point more compression would be an improvement!
A full point would be even more interesting.

First I want to add the 2.5 RHs, then go to full 2.5 w/X pipe.
Eventually I can see headers on the car.

R

REELAV8R

I guess if it were me I would optimize what I have first then work on other things that I don't have.
Headers can make a huge difference it scavenging effect for the exhaust. This will enhance not only the exit of the exhaust from the head but also the intake phase during overlap getting a bigger charge into the cylinder for greater cylinder pressure and more torque.
Adding bigger exhaust pipes may do little to nothing for you if the restriction is at the manifolds. It could, worst case scenario, make it worse by slowing down the exhaust flow due to rapid expansion creating an overall greater restriction to exhaust flow.
I believe the K&N filter is a good move for flow into the carb. Not having a source of cold air for it is not good for performance. I would work on that too.
Both of the moves I have described will improve cylinder pressure and torque. Sounds like that is what you are looking for.

What is the intake manifold that you are using? Dual plane, single plane, model?
The intake used can enhance or ruin certain areas of the RPM range. What you use depends on where you primarily want the power.

MotorHead

I tried to make 300rwhp with my 350ci many years ago with a solid flat tappet. I was only able to get to 296rwhp mark. I left it alone and it was a blast to drive.

I would venture to say that your combination makes the power it should make. You could change this or that but you are not going to make any power you would be able to "feel" and you would just be wasting money for 5-10 extra HP which would only come in at 6000rpm.

Go with what you have and be happy, that's about 400HP at the crank.

bashcraft

It could be that it likes 32 best because it starts detonating with more timing.

REELAV8R

Out of curiosity how you go about adding CR if you decided to? Would you leave the cam the same? How high were you thinking?

Taijutsu

I was going to either mill the heads,
or stroke it!
I was thinking of adding a half point of compression!
Maybe a full point if I could insulate and keep the fluids cool enough?

REELAV8R

Milling the heads would certainly be the easier way to go vs tearing into the bottom end. Stroking it would add a lot more torque and that might require some other changes like pistons and cam.

I just added .7 CR to my 350 and added a set of AFR 180's. It has made a dramatic difference to the performance. I would only attribute 30% of that to the difference in CR and the rest is the much better heads.

Do the TFS heads have a 180 cc intake volume or are they bigger? Is the engine lazy right now off the bottom?

Taijutsu

I have the 195 TFS heads.
A set of AFR 180s would be a big improvement!
Not sure what comp I have now,
more would be better. Hopefully!

R