what do you guys typically get done when you get your heads ported?? I am looking at a list that the machine shop gave me, and i could easily spend a million dollars there.

as of right now, i am getting:
1. new valve guides installed
2. getting her cut for 2.02/1.60 valves
3. pocket porting and flow tested
4. Port matched to intake manifold
5. Also going to have them install springs, locks and such

total price i am looking at is about $650.

Another question that i am curious about is the stock fuel system gonna be able to handle my ported heads and XE 230/236 cam?Of course i have all the usual bolt ons like mac headers and all the other fun stuff. The thing is, i can probably make room in the budget for new fuel pressure regulator and 30# injectors (fuel pump has 1500 miles on it), but i would be cutting it close.

i appreciate any suggestions,
trav

 

You will probably need to crank up the fuel pressure to around 55-58psi or get 30# injectors to be on the safe side. You are essentially accomplishing the same think either way you go but some people have a problem running that kind of fuel pressure on the stock injectors. Computer tuning is essential for peak performance but not mandatory right away IMO. Just be prepared for the never ending SES light on stock comp tuning. Also a better fuel pump should be considered as well but again probably not mandatory right away. Just watch for any signs of running lean in WOT situations. Food for thought.Good luck!

 

how would i watch for leaning out?? Does the car have obvious problems when she starts to lean out??(other than melting a piston)


thanks
trav

 

Some of the things to look at would be plugs although that can be hard to determine. The car feeling like it looses a slight amount of power on a long WOT pull. The best thing to do though would be to run a few dyno pulls with a wideband and monitor fuel pressure and see if it is stable. You can even do that without the dyno.

 

You can use a datascanner to read the amount of knock retard you see, and also listen for pinging. You can also monitor the exhaust gas temperature with a pyrometer. 1000-1100 degrees F is just about right. 1100+ degrees F is lean and under 1000 degrees F is rich.

 

The PCM will just return you FP to normal again. It won't last too long. You also need to program the PCM for that cam otherwise she will run like ****. Brian is pretty good. See Sig.

 

hmm, say i wanted to get an EGT sensor and gauge in my car.. where would be the best place to put the EGT Sensor, i know on my other car its right about 1 inc down on the primary tube of the header, same place on these cars? That way it would be easy to moniter exhaust gas temp

 

man, i cant believe some of the whackass advice people give





anyway........when doing heads/cam, bigger injectors are necessary for safe and reliable fuel. 30# will be fine, you can get a good deal on them from here the stock 24# injectors would be running way above their safe limit.

you dont need an adj fuel reg, because the pcm will just return it to normal like someone said.
however, a fuel pressure guage would be helpful.....if you see that your fuel pressure is dropping, then your fuel pump might be dying.

computer tuning IS necessary if you want the car to run safe, properly, be reliable, and get the most performance.
the inexpensive way is to get a mail-order tune from pcmforless or madz28.......this will be somewhat accurate, and is the minimum necessary for after swapping heads and cam.
or you can take it to a dyno and someone that has software to hand-tune your pcm......this is more expensive, but will have the best gains, and smoother running engine.

 

it sounds like i will be going with 30#ers for sure, then while i am working on everything, i am gonna get a pcmforless tune.

Thanks for all the advice,
trav

 

I spent $1100 just to have my heads ported, cut for double springs, decked, and reassembled....He also port matched my intake manifold.

OK, you do know that to install 2.02" intake valves in an LT1 head, you've got to change the valve seats completely, right? The stock seat will only take a 2.00" valve.

"Pocket porting" is usually just work done under the valves, I think (someone please correct me if I'm wrong). My heads had the intake and exhaust ports ported also.

Fuel system? Aeromotive AFPR (set at 38#), 30# Accel injectors, and a stock 95,000 mile fuel pump.

I give nothing but praise to PCMFORLESS! My car still uses a replaceable chip. I gave them my info, got a chip in the mail, plugged it in and went 12.0! It hasn't ever been dyno tuned.

Frank

 

Ok let me see if I can clarify my first post. First off there is a misconception that the computer controls FP, it does NOT. The only adjustment for fuel control the computer has is the amount of time the injector is commanded open or pulse width. When you add heads and cam and run stock tuning the computer will most likely see a lean condition especially at idle. This will cause the BLM's a representation of injector pulse width to increase (injectors are staying open longer). If they go above 160 on either bank the computer will set a lean code for that bank. A way to get around this (at least until you can retune the computer) is to increase fuel pressure. By increasing fuel pressure the amount of fuel added by the injector increases if the pulse width stays the same. So the computer adjusts the pulse width to compensate thus lowering the BLM. Only a quick fix yes but it does work for that problem.

Now what I ment by turning up fuel pressure to 58psi. Injectors are sized by several fixed factors one point we can change ourselves is the fuel pressure at witch they operate. By lowering the rated fuel pressure for a given injector you essentially make it a smaller injector, by increasing fuel pressure the effective size (lb/hr rating) will increase. A GM 24lb injector with approximately 58psi of fuel pressure will deliver the same amount of fuel as a 30lb injector at approx 42psi. So you see how you can get bigger injectors just by rasing fuel pressure. All you have to do is adjust the injector offset inthe computer to coordinate. Hope this clarifies what I was trying to get across.

 

Actually there is some good advice here IMO on several posts.

 

You'll get the same amount of fuel with whatever fuel pressure after about 30 miles (when the pcm adjusts the injector pulse width to compensate for the added fuel pressure). You can install 2.02 1.60 valves and NightTrain66 uses a machine shop that does this without changing the seats.

Joe

 

Somewhat correct but somewhat missleading as well. The engine strives to maintain the correct 14.7:1 fuel ratio all the time in closed loop except in PE mode. Now when you install a larger cam and ported heads and the stock tuning is retained the computer will see a lean condition in most cells, (most pronounced at idle) it will then begin to richen the fuel mixture to reattain the 14.7:1 ratio it continually strives for. Now what this causes if you keep the fuel pressure set stock the BLM's can sometimes go over 160 thus setting a lean code. By increasing fuel pressure the fuel mixture will only change for a short time as you stated but the result is the BLM's drop eliminating the high BLM 160+ lean fuel code. On the other hand if you continually drop fuel pressure at some point the computer will no longer be able to compensate and the engine will not run properly as with a failing fuel pump.

Now again with the 30# injector issue I still think you may be uncertain what I am saying. If you have a recalibrated computer for 30# injectors you can use your stock injectors at approx 58psi and they will work the same as if you had 30# injectors set at approx 42 psi (or whatever the the advertised fuel setting is for the injector) thus eliminating the need to purchase larger injectors. As I said in an earlier post some believe you wear out the injectors sooner by doing this I don't think however there is any good data supporting that theory especially when GM now runs a similiar injector in the Z06 LS6 at 58psi. On the other hand running the injector at 70+psi I would be concerned about lock up.

 

With 85,000 miles on the stock injectors, do you think it would be a wise decision to just simply upgrade the injectors anways, even though i could get away with the stock injectors on increased fuel pressure??

Basically, i want to protect my investment, and not have to worry about melting a piston if i take her up tp 6400 RPM.

I really appreciate all the information though, i thought i knew alot about these motors, but you have humbled me


thanks
trav