I'm possibly buying an 85 vette tomorrow, all stock and nothing wrong with it. If I get it, I wanna put a bigger cam in it and probably some headers for now. What would be the best cam and lifter kit to use for a stock tpi? I'd like low and midrange power as I've read that the stock intake sick on the top end and a decent choppy idle. Also, is there anything else I would have to do? I've never really messed with the tpi motors just carbed ones haha. Thanks in advance!

 

You'll get 1,000,000,000 different answers here to that question.My advice to you is call Summit Tech at 1-330-630-0240 I've been using them and thier advice in matters like this for many years. Talk to a tech and run by him what your looking to do with the car and he'll suggest the best combo to run, with or without a chip or injector upgrade.

 

Headers / free flow exh best mod for TPI.
Cam change basically a waste of $$ until you do intake mods; the intake is the major restriction to power

Cams with " choppy idles " don't work well with EFI computers ; especially on stock setups

And you trust someone trying to sell you something giving you advice
over members who have actually done it and know what is cost effective or not?

 

Everybody is different and expect different things from thier car and like I said "There is gonna be a million different answers to this question" so Summit would be a good starting point. Everybody here bought thier stuff from somebody and everybody thinks thier set-up is the best, I've just decided to buy my stuff from Summit, thats all.

 

The first combination I had on my 85 was a stock intake with Competiton Cam 260AH flat tappet cam, roller rockers and headers. The cam is mild enough that it does not require a new tune but it was enough to support the much better flowing Super Ram intake I installed later. I ran that cam with the Super Ram and AFR 195 heads and I was pretty happy with the performance. The roller rockers add a few horsepower jusy by reducing friction. The headers are absolutely necessary and probably the best modification for the money. I would do the headers first. The other thing not mentioned yet is the heads. The 85 and early 86's had cast iron heads. Some new aluminum heads would help a lot. Just make sure you make mods that will support future mods. Once you feel the extra power, more will be better.

 

You're right, there is gonna be a million different answers and, like your's, most of them will be wrong. rodj summed it all up pretty well in the few words he wrote. But what do us old farts know?
To the op, get to know your car and do a lot of reading on here, like rodj said, a lot of us have already taken our lumps and know what works and what doesn't. A choppy cam in a tpi engine is like screen doors on a submarine, useless. In the end with such mods as you are planning your car would be slower than it is now. Once you port out the entire tpi setup then get some deecent flowing heads, even the late model 128's are better than the iron heads on your car now. Get the exhaust opened up & breathing, then you will be ready for a bigger cam but it will need a custom chip so you won't kill the engine. Get the idea?

 

with those above. You might be limited in the cam if you live in a SMOG state. The 85 responds well to exhaust modifications.

I would suggest that you do a search for Vader86 (Forum member) and then click on his name and read his site information. You will be given MUCHO information here that will point you in a direction.

 

Is any of these things gonna require a converter swap?

 

Thanks for all the advise...I am definitely going with some headman headers first and might port the intake, etc before camming it. I've got around 800 or so at the moment so I'm pretty limited at the moment.

 

I would listen to rodj.

 

Do the headers port the daylights out of the base.
Look for a deal on some used aftermarket runners, then port those
Some can be ported some cant but they are better than stock.
Can do a little to your plenum that will complement the pieces but by itself no real gain.
Little at a time.

 

http://temp.corvetteforum.net/c4/vader86/

 

you can cam these motors , and they do work well with the EFI computers.
you must tune the chip.I have 530 lift 230 duration@ 50 Run great. you must port intake for top performance.

 

Someone asked the same question recently, and surprisingly got the same answers !
just for info rm1sner, cam swaps in a c4 with the engine in are an expensive time consuming PIA, you will need a cam, lifters, timing set, probably a new water pump, etc etc, lots of tools and patience too !
Listen to what the other guys are saying and stick with the intake/exhaust mods first, if you want more lift go with 1.6 rockers, your $800 budget is going to keep you limited to what you can achieve,
pick one or two mods at a time and good luck

 

Hi RM1SNER

Sorry for the in depth reply ...

The 85 responds well to headers, adjustable fuel pressure regulator (40-45 psi) and cold air intake and tuning. Doing that knocked a second of the 1/4 mile time on my 85 did as to when i first got it stock standard. 14.7 to 13.4. now it is supercharged and faster but that is another story.

That was many years ago, think of your vette as a girlfriend.
It gets jealous even vengeful ... you spend money on the engine and the gearbox will blow !! then the aluminum half shafts will twist and snap she may even try to kill you. She never did anything wrong when she was stock standard, had her 10 years without a thing going wrong... till i started modifying her.......

Go mild in the camshaft department to use the low down hp the 85 has. I would not recommend going to a hot cam without spending a lot more money, these engines are great torque monsters. When doing the hot cam you will lose the down low torque and need to ditch the tpi setup get aftermarket heads... you will then make more power but all that off the line power will be gone and be well up the rpm range.

I have been there and done that in the past, 8,500 rpm screamers... great for a weekend toy car but a pig in traffic or everyday use.
Unless you drop the clutch at high rpm or have a 4,000rpm stall converter in an auto trans they can be a pig to get off the line quickly without attracting unwanted attention. Yes above 4,000 to 8,000rpm it will all make sense but to do that you will need a better bottom end all the way thru to the tires.

Think of engines as packages, you could get a camshaft of a 600 hp engine and put it in the 85 vette. It wont work ! possibly bend valves to begin with as the pistons need the correct reliefs ... It will need the inlet manifold,heads, the right compression, conrods, pistons to make use of it all. Consider how you want to use your vette then you can put together what will work. there are tried and proven packages that will work.

Ask yourself how fast you want to go? 12,11,10,9 sec quarters and people will inform you on what works, and how much you will need to spend to get that. A lot on this forum will agree that people ''better a vehicle'' modify them to the point of making them undrivable and selling it to get a daily driver to cruise in.

Mild camshaft, heads, exhaust and aftermarket intake will really make your vette come alive and be well mannered on the road but consider how many miles that engine has done and can the bottom end take it ?

A cheap way to go is nitrous oxide, but refilling those bottles gets expensive. It is so addictive another 50 hp? another 100 hp? until parts of your engine are lying on the road.......

Blowers and turbos are great also but you can build a very good engine for that money...

Hope our experience helps you avoid some of the pitfalls and find out what works and what doesn't.

 

Your specs mean little without the LSA which determines what the computer thinks about the cam

Invariably the cam the OP thinks he wants with a "lumpy" idle ie; big valve overlap will have a LSA that will at least take a lot of tuning to get a stable idle

 

See that's the thing I wasn't sure about...I didn't know what all the computer was involved in on the earlier corvette. Also, I've got a good edelbrock intake and carb, would that be a better way to go than the tpi?

 

And that is exactly why I told you to get to know your car and do some reading here on the forum. You catch on fast. I'm 63, had my car since 1999 and have rebuilt the entire car and I still learn something here almost every time I get on. My opinion on the carb, don't do it, and that is strictly my opinion. If you do go with a carb then the computer can be ruled out of everything but I prefer the smoothness of the injection. If injection was not a good option for power then why did NASCAR just make the switch??

 

Very good point, but I think I might carb it until I get a chance to get a better tpi set up...any opinions on the edelbrock tpi system for future reference?

 

It's your car, you can do whatever you want to. Keep in mind what was said about the choppy idle cams, it still goes for carburetion too. When I was about 18 years old I put the absolute wildest cam I could find in my bone stock engine. Everybody thought I had one bad assed machine by the sound, truth was , it couldn't get out of it's own way.