OldManZ

As of today I am a proud new owner of a 89 formula 350! I scored this beaut for 1k off an old friend who is moving and needed her gone asap. The car has not run in years due to a dead battery/starter and an overall lack of motivation from my friend. He has thousands invested in the motor alone.

I don't know alot about TPI engines so I was hoping some of you could chime in about what I should expect from the modifications done.

Here is what I know about the engine from paperwork and receipts that came with the car....

72cc Sportsman2's 2.02int1 1.6exh 3/8 studs
Promotive roller rockers 1.5 ratio
Cam Crane Compucam #114132 Lift .454Int .480Exh Dur 276/288
Adj fuel reg
.30 over bore
balanced
Aluminum flat top pistons (sterling345NP?)
clevite bearings
coleman oil pan
Edelbrock headers
TPI intake port matched to sportsman heads
New injectors std. Ignition
Accel 8.8 wires
Air foil
No tune

I do not know the C.R. or how many lbs the injectors are. I assume there is alot of pwr left on the table with factory tune and stock TPI setup? What kind of ballpark pwr numbers or 1/4 times do you guys think with a good tune and a holley stealth ram? 3.42 gear? I have no idea where I stand with this car power wise.....

OldManZ

Ok well can you at least tell me if this thing will beat my bolt on 350Z that dynoed at 280whp/260Tq and ran a 13.765 in the 1/4?

If this thing can't beat my bolt on 350z with the addition of a good tune and stealth ram I won't bother investing in the engine.

OldManZ

Really? Did I post in the wrong section? No one can give me any kind of answer?

ASE doc

It's difficult to say what you might expect from the motor. Are the pistons true flat tops or flat tops with 2 valve reliefs(-4cc), or 4 valve reliefs(-8cc)? What is the deck height? The 72cc chambers are big for a 350. If the pistons are not true flat tops, the compression could be down in the 8.5:1 area which is not going to work with that cam. You will know as soon as you get the car running and of course clear out alot of cob webs and likely old rotten fuel.

Low compression will be evident in really poor idle quality, poor streetability and throttle response from lack of low end torque. You may already know that a big cam needs high compression to compensate for the compression lost through valve overlap. Once the motor reaches probably about 3,000rpm on that cam, the loss of compression is overcome by the increased evacuation and cylinder filling created by the same overlap that kills low end torque.


Trouble is, unless the intake and head combo can support high rev power, the motor runs out of wind not long after it catches up to the big cam. What you end up with is a very narrow power band. Since you don't mention this motor having a siamesed or other modified TPI, other than gasket matched stock base. I have to assume it won't really support much more than 5,000rpm. This could leave you with about 2,000rpm of actual power band. Even then, the stock TPI is not sufficient to feed the cam and head combo's air flow. Plus assuming that the cam is flat tappet and about 110lsa, the reversion pulses it creates will play havoc with the long runners further killing power.

I'm not saying that TPI, when built correctly, can't support a large cam. The cam I run is huge(240/240 @ .050, .560/.560 lift. But it's specially ground, on a roller profile with wide lobe separation(112lsa) to reduce the overlap that creates reversion. Plus my base is a large port casting(superram) that has been ported to it's as cast limit, my runners are significantly larger than stock, and my plenum is hogged out. All to support the big cam. My heads are also built with 2.02 intake valves and 190cc intake ports, ported to 195cc, but they are a specially designed high velocity port that helps improve mid lift flow to make the most of the long tubes. The chambers are 65cc and compression ratio is set at 10.3:1. All this and my motor is right at the edge of what works. The whole idea was to make the most peak HP out of long runner TPI and if it were anymore radical, it would be just about unstreetable.

So, I don't know how the combo you just inherited will work. The only way to know is get it going and give it a shot. Maybe it hauls butt. If not, you at least have some decent pieces to work with and the whole point of this is to do what ya can with what ya got.
To answer one question I think I heard you ask: the Stealth Ram will work alot better with that cam and head combo.

OldManZ

You know your stuff! Thank you for the great response! Your right.....I guess the bottom line is I don't know enough of the details like C.R. etc. I will have to pick up a HSR to feed that cam and like you said at the end of the day I have inherited some nice parts to play with.

Your setup must be fun as Sh$t! Sounds like a max effort L98!

vetteoz

iTrader: (13)

I'm not seeing anything that points to massive amounts of Hp over stock given the good Vette TPI made 245Hp ( at the crank !)
Your cam 210/216 @ 50 is not much larger than the stock '89 TPI cam 207/213 415/430

ASE doc

Vetteoz is right. I didn't look up the cam specs till just now. From the advertised duration and lift numbers you posted, I was thinking of a larger cam. The P/N you posted is barely larger than stock. It is a flat tappet so it still may not work well with tpi. It is too small for 2.02 valves. So while you're looking for your hsr, you should be looking at cams too.

ninetyone

iTrader: (2)

210/216 would be great for a stock TPI car though for a little extra oomph.