New cam, will i need a chip?

[militant_x]

Hello everyone, im very new to fuel injection and really have no idea what is going to happen to my engine if i go through with the following mods.

for a 1986 corvette 4+3 with 130k miles on it im doing the following:

cam kit:
comp cams extreme energy 274 ( .487/.490 lift and 274/286 duration)
matched lifters
retainers/clips
mathced springs
timing chain


then im getting some headman headers and am going to wrap them.. the wrap is cheaper than the thermal coating.

and a K&N

my main concern is that my engine is going to run lean because i dont know how to (in carb terms) jet my fuel injection richer. I really have no idea how fuel injection works, will i need to have my computer reprogrammed? Id like to know how my car will run without the burned chip. If i need it though, how much does this cost? From what ive been reading its a long trial and error tunning process ($$$).

btw, what is the max lift i can run inside the stock L98 aluminum heads.

Also the oil im supposed to run is 5w30 but this engine has a 130k miles on it. would something thicker like 10w40 be better for a hot place like miami florida? I dont care about the loss of 2mpg or whatever it is. =)

thanks,
Chris

 

[robert kirk]

Wraping the headers will cause them to rot. This is a bad idea, I speak from experance. I run 15w50 mobil 1 in south texas. No problems and good pressure, also keeps the temp down. As for the chip and the head specks I have no idea. But I am curious about the answer. I would like to do this to my 92 lt1 in the future. Having the headers coated is worth the money. robert

 

[militant_x]

Thanks for the info on the headers, might have to put off getting them a little longer if i want them coated.

thanks.

 

[vader86]

I wouldnt run anything thicker than 10w30, but 15w50 Mobil is just fine (since its Mobil).

I would not use Hedmans, bad quality reputation, and wrapping will cause them to rot away. Hooker 2149/2151 ceramic-coated would be a much better idea, but more expensive also.

A chip will end up being necessary, but i think you can handle the lift, for the time being add an adjustable fuel pressure regulator and crank the pressure up. A scanner would be extremely helpful here, so you can see the A/F ratio.
I would get a chip from Ed Wright, fastchip.com.

 

[militant_x]

thanks for all the feedback guys. looking into all of it now =)

~Chris

 

[WhalePirot]

I had my TRACO headers wrapped and painted with ThermoTec for ten years and they are still fine. I'd heard about problems but such was NOT my experience. I have them here; have inspected them and tapped away on them and can find NO issues with them at all. They're not rotted nor crystallized. They were not coated, but I would be happy, even now, to clean them and coat them for use.

I will wrap my new, coated TPIS headers soon, as far down as I can; likely past the Y-pipe to the CAT.

I wonder if the 'rot' has more to do with climate or gage of the tubing than the wrap.

The hot coating smoothes out the inside and the outside of the headers. They look better, stay nicer, longer and have better flow characteristics when the insides are coated. It does little though, in my judgement, for lowering underhood temperatures. The thicker, ceramic coating might, but I have no experience with it.

I cannot tell from your cam grind if your computer will fully adjust the mixture, but it doesn't look too radical. Enough drop in vacuum from an aggressive cam will have the MAP sensor tell the ECM that you have the throttle open more than is actually the case, causing the ECM to add fuel, making your car run rich. You know how to read tailpipes and spark plugs? The car should run okay until you can get the chip, if needed. Too rich for too long may cause problems with your cat.

I wish I could get copies of the great soft-bound book (Automotive Engine Electronics, by Dr. E.C.McElroy) that took the mystery out of ECMs for me, but it's out of print. Written by one-time Chevy line mechanic, who got a PhD and taught at GM Institute, it is great for information and readability!

Enjoy! mike