evilstuie

Hey Guys,
Trying to find out what heads and intake would be a good upgrade from my stock ones on a 86-95 350Chev TPI with current intake manifold#16006615.
Now... my real question is this:
I've heard the terms so far LS1-LS4, LT1, L98, vortec, etc when dealing with 350chevs.... Is there a site or something that can tell me the differences between each "model" and whether the "Lxx" designation refers to the block, the heads, the intake or a combination of the lot, and by that I mean can you have a standard 350block(if there is such a thing) with L98 heads and a LT1 intake or is everything restricted to the Lxx of the block?

I've just been thrown from dealing with Australian motors (holden 202's, 253's and 308's, and very basic knowledge at that) to American 350 chevs, TPI, ECU's and all the rest and now having to deal with a whole heap of unknowns about what I can and can't do to beef up the motor and make it run smoother.

327Chevy

This is a big question requiring a long answer. There are probably good write-ups here at thirdgen.org.

One article I can refer you to for the differences between small block, LT, LS, etc is here:

http://www.chevyhiperformance.com/th...ory/index.html

evilstuie

Thanks for that.
Now I can see what I'm dealing with.
I now know my engine is just a stock 350 TPI.
Now what do I do to make it better?
Should I invest in better heads, cam, injectors, intake manifold, and if so which ones?
Or should I invest in another motor?
If so, which would be the best choice?
I don't want to change from the t700 i have in there now, so I "think" that rules out a 6.0L engine, but is there another 350 i can put in and see considerable HP increase without the need for changing much other than the engine and ecu if necessary?

327Chevy

You are asking "what is the path to my goal?" I ask you "what is your goal?" There are so many options.

Do you need to meet emissions testing in Australia? Will it be a sniffer test and/or a visual test?

What is the intended use of your vehicle? Daily driver? Weekends only? Track only?

How much of a factor is budget?

Also there are a lot of threads on this website that are similar questions. You might just want to read through some of them.

evilstuie

And just to check something that might have to do with my engine running a bit rough and crap...
injector#5235301... 19 or 22lbs injector?
those are the ones i have in my 350tpi at the moment. are they the right pressure or has someone put the 305TPI intake on and not changed everything over?

evilstuie

Emissions controls - no.
Nowhere near as restrictive or monitored as USA.
I use the car as a daily driver, but work is 2kms away so its not that long of a trip, but I want the car to be reliable, run smooth, but still have some ***** if I end up next to a riceboy car at the lights.
I'm new to engine modifications other than extractors bigger carby and better air filter. This is a steep learning curve but I'm getting there. I think I have a fairy good idea how TPI/fuel injection works and is nowhere near as daunting as I first thought.
I'm not quite up on compression ratios and how they affect performance, but I know it has to do with the heads rings and pistions yeah?
I know the cam controls intake and exhaust valves and the timing between each, but the measurements of which are dutch to me.
The car already has extractors, and I was thinking of getting performance heads, and a cam that can bring up the mid range power, but nothing to far from the norm, i like the lump cam sound but i have enough issues at the moment with the car cutting out when the air con goes on from idle.( in the process of fixing)
My big problem with the cam and heads is i dont have a clue what will fit it, i keep reading about 350tpi engines with l98 heads or lt1 heads etc, but when i asked an american imports place if they'd work they said no. So I'm trying to find a brand & part number of compatible heads and cams, and preferrably a recommendation of each to go in my 86-95 350TPI engine.

Edit: Budget is a factor, unfortunately the cars you have a dime a dozen of in the states are very rare here. AU$17,000 for conversion to right hand drive, and the rest makes the prices for even an average Trans-am that needs some work to be AU$20,000. I got this one for $15,500 which was lucky but that was most of my allowed budget by the missus.
Basically anything I spent on the car has to be on the sly so she doesn't notice :P

327Chevy

First realize that there is no "right" answer to your question. Any answers you get will be opinions. Here's mine:

OK well there's more than one way for you to go. IF you decide to stay with the stock intake manifold, runners, and plenum on a TPI car, realize that GM designed this setup for midrange torque. (I am not familiar with the intake part number you quoted.) Pick your components accoringly. Go mild with the combination.

I will start with also assuming you will use shorty tubular headers, with a y-pipe into a single 3" catalytic converter, and 3" single intermediate pipe catback system with crossflow muffler and 2 outlets. This is pretty standard for mildly hopped up street f-bodies around here.

You probably want to pick a set of heads that have 64 cc combustion chambers (the bigger the chamber, the lower the compression ratio). 64 cc is typical combustion chamber for a 350. If you are using your stock manifold, this rules out the gm iron vortec heads which are an excellent value, but require a special intake. Cast iron heads are cheaper, aluminum heads weigh less but cost more. You are talking about saving 50 lbs (kg=??) On a budget buildup the extra cost won't worth it, go with iron. On an all-out buildup, yes go with the aluminum on the heads. For a mild engine like this one, the heads don't have flow monstrous amounts of air. Probably keep the intake runner volume under 190 cc max. If you can, try for the bigger valves (2.02" intake / 1.60" exhaust). If you want to see a wide variety of heads, try visiting summitracing or jegs websites. They are mail order speed shops here. I don't know what the equivalent in Australia would be. Anyway once you see a few interesting heads on those websites, come back here (thirdgen) and search on them to see what has been said.

Now once you have picked your heads, pick your cam. Call some cam manufacturers like Lunati, Competition Cams, Crane Cams, etc. They will make a recommendation. I think you have roller cam block. You will need to verify that, but for now I will assume you do have one. Tell the cam company about your setup and that you want a roller cam (verify) with a decent idle and an rpm range up to about 5000 rpm. That upper rpm range is limited by the stock intake manifold, runners, and plenum. This cam will generate good low end and mid range torque. One place to learn about cam specs is here:

http://www.lunaticams.com/Tech/Cams/...fileTerms.aspx

and

http://www.lunaticams.com/Tech/Cams/CamSpecTerms.aspx

Once you have a cam picked out you will pick your compression ratio. Read this article to learn how to do it, and what is an appropriate selection based on the octane of the gasoline you plan to run.

http://www.popularhotrodding.com/eng...eze/index.html

Knowing your desired static comression ratio will help you pick your pistons and head gasket to go with those 64 cc heads. Hypereutectic aluminum pistons would be a good choice for a mild engine like this. If you think you may use nitrous someday, skip the hyper pistons and just get forged pistons.

That is a general intro to the basics. Do some other reading on this site. Come back with more questions. Pick good quality, brand name, but affordable parts and you will be happy. All aspects of the combination need to be matched to each other for good results.

Oh yeah, you will definately need a custom tune (chip) to optimize this combination. Again, read the good stuff on thirdgen.org. You may need to look at fuel pumps, injectors, etc, keep reading thirdgen.org.

evilstuie

Thanks for that. Those links were very informative and I think I've got a betetr idea on everything. From what I gathered the compression ratio of the heads to choose depends on how cool the engine runs, how good they are at taking heat away from the car, and what octane fuel you're going to use, is that right?
They do a little bit in the way of hp increase on there own but work heaps better when matched with a cam?
And when i change the heads i should change pistons to flat tops if they're not already?
I have a MEMCAL chip in the ECU already as some clever **** put a 305TPI intake on with 19lbs injectors and just messed with the ecu tog et it to run(using the term lightly)
So for now, 22lbs injectors, new spark plugs and an ECU remap is first on the list.
And that will include a facelift for the intake, sensors etc.
Then I'll look at ordering a set of heads, pistons and might as well get valves etc at the same time, and a cam to suit.
sound about right?

Also the exhaust is extractors 4 into two into 1 into cat either side then both sets join for single 3" exhaust, but i want to split at the cats for dual 2&1/2" system.

327Chevy

A couple follow up items. You would only replace the pistons as part of a rebuild to your short block. Don't necessarily have to rebuild if you have a low mileage, good condition short block. If keeping your existing pistons, you would instead calculate your static compression ratio with the new heads, then use the methods in the popular hot rodding article to pick a cam with a long or short enough duration to give you a reasonable dynamic compression - so you don't get knock.

Yes flat top pistons would probably be a good choice - but depends on the combination. Make sure you get a set with 2 valve reliefs each. Remember to check compression on paper before you buy.

The basic idea is that for a performance engine you want to run as much compression as you can while safely avoiding knock for the fuel & temperature you are running. The "more" cam you have, the more static compression you can use and still not knock.

By the way, are extractors in Australia what I am calling headers in Texas? Tubular pipes instead of cast iron exhaust manifolds? Just curious.

Are you planning to do the work yourself or have a mechanic do it? If using a mechanic, get his opinion on the combo before you order. I don't know what's popular in your area.

evilstuie

yeah, headers=extractors here.
I'll prrrrrrrrrobably get a mechanic to do do it, I'll get another block for me to do my first engine build, thatb way the car stays running for now :P

aliceempire

iTrader: (14)

I have to agree with the advice 327Chevy is giving so I'm not trying to step on any toes here but what heads do you have? Maybe a shop around there can port and mill down your heads for cheap enough. Sorry I'm not real familiar with the availability of parts or shops by you for small blocks. If you need help finding out what you have check Mortec.com

jamon8

iTrader: (3)

I couldnt read anymore before i had to suggest

1.6 roller tip rockers

exsaust

port out your upper pleneum

dont get rid of the tpi

its the grandfather of all multiport

and it looks cool.

evilstuie

jamon8: what would the 1.6 roller tip rockers do?
how much would i be looking at for all that?
and how much more hp would i get?
I'm assuming the engine is a 290hp crate motor but not 100% on that.
I can't find the number for the heads

jamon8

iTrader: (3)

rockers are a wear item meaning you will have to replace them one day after they do some damage

the advantage of putting them on a car that is not performing as well as you would like is a little push in the cam area without replacing the cam

take the lift on the cam you have and divide it buy 1.5 and then multiply by 1.6

http://cgi.ebay.com/ebaymotors/Small...Q5fAccessories

evilstuie

Ok, new trick.
I'm going to get the Holley Stealth RAM MPFI system to go on my motor, and do away with the TPI stock intake.
http://www.thunderracing.com/catalog...vid=6&pcid=268

Just need to know if i can keep my Distributor or if i HAVE to get this one:
http://cgi.ebay.com/ebaymotors/Holle...11410009r17466

Then I'll need the cam and heads to go with it. Unfortunately the car has too much work I need to do in other areas so once I have maybe 400hp+ under the hood , thats where my engine work will end. I don't want it to be a neverending quest for more power, I just want enough so a CIVIC won't laugh at me.
If you can suggest a cam and heads to suit this setup it would be most appreciated, and model numbers/price.
Trying to get HP on a budget.
I don't want to need to run higher than 85 octane, but would like the option to, and I don't really want to install a stall converter if i can avoid it.
I want it to idle and not have to worry about it cutting out.
I wish I had the time to learn about cams heads and the rest but my stoopid job takes most of my time and the small amount of time i have left over would be better spent driving my dream car rather than researching and working on it.