4AGE cams......choices, dyno results and discussions!!!

[Course_Out]

Howdy everyone, just chasing some experiences/opinions. Thought it might be better to add it here, rather than start a new thread.

I run a bigport 4age equipped ae86 as a hill climb/drift car/lap dash car. As with most 4age's it needs the valve stem seals doing and we have discovered the current head is no good (heavy wear and scoring on the cams and the head) so I have gotten hold of a second head to put on. While it is apart to replace the stem seals I figured we might as well put some cams in it.

Now basically I want to keep a strong mid range and have a little more up top (our local course is mostly second gear, so a bit more legs wouldn't hurt). I intend to keep the standard exhaust manifold as it seems to not be much of a restriction at the power levels I am chasing. To remain in my class I also have to use the standard inlet manifold, although mine has been modified to have a bigger TB. The car is fitted with a very old Microtech programmable computer, so a retune is easy. Diff ratio is 4.3 and cannot be changed.

I have been looking at the Tomei Poncams as they seem to fit the bill of what I am after, and can be had for around $600 from RHD Japan. I will be changing the valve springs as well, mainly because I feel it is cheap insurance. Has anyone used these cams? Any opinions on whether these will achieve what I am after? Or are there any local grinds that might do a better/similar job for around the same money? These are the specs:

SPECIFICATIONS:
-- Remarks: Outer Shim Type
-- Duration (degree): 264°
-- Max Cam Lift(mm): 8.10
-- Max Valve lift(mm):
--- Intake: 7.90
--- Exhaust: 7.85
-- Cold Valve clearance (mm)[+/-0.01]:
--- Intake: 0.20
--- Exhaust: 0.25
-- Lobe Center Angle (initial):
--- Intake: 106
--- Exhaust: 110
-- Base Circle(mm): 28

Thanks guys, any help is appreciated

[gerkn]

Hi New to the forum, currently working on 4AGE build myself for my AE92 GT-S and found this thread. My build is for the street but I would like to get into amateur track racing just for fun.
My first build I'm looking at Tomei Cam gears, Tomei 264* cams, 4-2-1 header, thin head gasket .8mm?, simple pnp and valve job, and obviously timing kit replacement and short ram intake with stock exhaust size straight pipe with chambered muffler and resonator. Everything else stock.

Questions, I would like to see roughly a 40hp increase from this as it will cost me around $1300 to build. Can I see this kind of gain WITHOUT ITB's and stock ECU? I'm basing my info off of the dyno graph previously posted about the smallport with a similar build on page 4.

Has anyone seen an actual number of HP or KW gain from switching a ram intake to ITB'S running a 264 cam?

and finally, any tips on the best way to increase CR to 10.5-11:1? will a .8mm head gasket suffice or will I need to deck the block or change pistons?

[Sam-Q]

Short stacks are a bad idea, you will just lose power everywhere. I also suggest a 20v oil pump and as for your compression ratio you didn't say which engine you have now exactly?

Quad throttle do work really well so I would suggest this with a new tune over the stock ecu

[gerkn]

Sorry, I knew I forgot something. I have a 2nd gen 16v big port with 42mm crank 9.4:1 compression (86kw).
I'm trying to do this on a budget as close to $1000 usd as possible, also trying to avoid any low end work for now.
Going to work on building a megasquirt and MSD ignition eventually after the engine build when I get more money.
Huge plans later on but trying to keep it cheap so I can get to learning how to race on the track or autocross.

For now I'm wondering what kind of gains I'm missing by not going with ITB's and what kind of difference I would see by increasing CR.
What is the best way to increase my CR without ripping out the block? is 10.5:1 more attainable than 11:1?

[Big T]

The only way to bump compression without changing pistons is to deck the head and block and run a thinner HG. This however is a poor substitute for pistons as to get up to the CR you want you will need to skim a fair bit off. You will lose squish areas in the head and I'm willing to bet you will have issues setting up the timing belt due to the loss in height of the engine.

You will need to pull the crank/pistons out anyway to get the block decked so I would suggest getting pistons at the same time.

[Matt]

You're best to wait until you can do the pistons as well.

You can get a decent set of pistons for around $400. I'd be looking into 12:1 compression or there abouts given the decent fuel systems we have today and aftermarket ecu's available.

[Sam-Q]

I suggest fitting 100 or 110mm stacks and then saving your money for the engine management

[Sprinter Freak]

hey guys,

Am putting a set of Toda 272deg 7.9mm lift cams in my 16v 4age. also putting a set of quads and going an aftermarket ecu as well. But am wondering, will i need to bump up the compression to make the most out of the cams? i've had the engine rebuilt and they skimed off a fair bit of the head and the block so id assume would have raised the compression a bit. Am also running a cometic head gasket(either 0.8mm or 1.0mm thick cant rememer)

Am also wondering how much of a difference would it make getting the ports de dagged/lighty ported with no bottom end work and mildish cams?

[Matt]

Yep Ryan, more compression means the car will rev out further. Bigger cams means it'll make power later in the rev range.

[Slimer86]

The higher duration lift of cam you choose denotes the requirement to raise compression. This is due to the loss of dynamic compression as duration of the camshaft increases.

That being said, I have witnessed a silvertop 20v respond very well to a toda 272/264 camshaft setup with no change to dynamic compression (pistons or thinner head gasket) but static compression is higher out of the factory in comparison to a big or smallport.