moreyes

Hey guys,

I'm probably getting this motor for my 85 T/A http://www.sdpc2000.com/catalog/3508...-Long-Block-Pr the question is, should i keep my tpi or should i drop a carb on it.

What are the pros and cons of keeping the tpi or switching to carb?

five7kid

iTrader: (14)

Keeping TPI:
Pro - stays emissions legal
Pro - better gas mileage
Pro - little things like torque converter clutch lock-up continue to function.
Con - if the TPI has "issues" with the engine, harder to tune.


Going carb:
Con - not emissions legal
Con - gas mileage will likely go down
Con - have to figure ot a way to lock up the TCC
Pro - cheaper to tune

As to the engine:
Pro - cheap.
Con - your 305 has a better cam right now.

Amoung other things...

moreyes

thanks for the info man
I guess TPI seems better. On the same note...
Is it true that the 85 computer is the same as the 85 corvette computer for the TPI? If it is then why would I need a chip? I heard that its harder to tune because its really slow compared to the later ecu models. Would it be a good idea to get a comp cam probably the 12-262-4 or 12-268-4?

five7kid

iTrader: (14)

The computer may be the same (I honestly don't know), but the PROM most likely is different. The Vette had a 350.

I don't have any first-hand experience with them but I understand the MAF systems handle displacement increase fairly well. The '85 3rd gen TPI wasn't very friendly to PROM modification (from what I understand).

Oh, another "Con" to TPI - less power than carb. It probably won't make 290 HP with TPI. It would have to have headers to do that, anyway, and that's a gross flywheel HP number, not the net flywheel quoted for the car's original engine.

And, another "Con" for that engine - your current heads are better, too.

BruceEmbry

This is the exact engine that I'm have in my 82 Firebird with TPI.
When I did my conversion a company modified the TPI intake to fit this motor. They also sent me the correct computer, with prom, and injectors. The only problems that I have had with the combination is due to an accident in 2002. I finally got it to run correctly agian back in September.

I have complete SLP exhust and y-pipe with high flow 3inch convertor. Everything else is set up as 1989 L98 , dual electric fans, etc. I am still running the v-belt setup

I hope you realize that this a low compression motor.
My recent emissions test measured
C0 = 0
N2 = 18ppm
So the engine is very clean.
I am using a 180deg thromostatic and heated O2 sensor.
I run mid-test gas.

86irocmike86

its not at all possible to pass emissions with a carb on this motor, cause that was the setup im going for. i have a thrown bearing in my lg4 and i am gunna upgrade to that crate motor and throw on my heads and manifold and carb.

moreyes

Was the tpi 89? Whats the importance of the motor having low compression?

BruceEmbry

It not inportant to have low compression, I was just point out that the motor is not really consider a performer. I pick the motor because it was improvement over my 305.

I not sure where my TPI intake came from, I think it was from a Corvett being that the fual connections are on the left side of engine. Right side is drivers side.

The main drifferance between the 85 and 89 setups MASS AIR Flow burn off, better computer, and no cold start injector.

You can use everything off of you current engine except for the following
Knock Sensor
Injectors, you have 19, you will need 24.
Prom/Memcal pak.

I would recommend that you upgrade to the 89 computer and eliminate the cold start injector and adapte to the new burn-off relay.

My TPI intake came as a kit from http://www.fuelinjection.com
It included everthing listed below

Intake Manifold / Intake Tubes / Water Outlet / Bolts
Plenum / Plenum Extension
Fuel Rails / Fuel Injectors
Throttle Body / Fuel Pressure regulator-Vacuum Hose Assembly
Coolant Temp Sensor / Manifold Air Temp Sensor
Knock Sensor / ESC Module / Oxygen Sensor
Mass Air Flow Sensor
Throttle Position Sensor / Idle Air Control Valve
Throttle Cable Bracket
Electronic Distributor / Small w/Ignition Coil
ECM / Computer w/Calibrator (EPROM NO VATS)
Engine Wiring Harness w/OEM Color Codes / Connectors
Wiring Diagram and Installation Instructions
Electric Fuel Pump-60 PSI/30GPH & Inline Hi Flo-Filter
Start up technical support

Thay charged extra for the complete emission harness and fan control.

In 1998, when I did my converson, I wanted a trouble free system that would last a very long time. I spent lots of time with a parts guy at the Chavy dealer in Elizabeth City, NC. going though everything. It was a conversion that was done right the first time. Except for the parts listed above the conversion went in with all new OEM parts. So when it started up the first time it ran good. The only problem that I can remember with the startup was with a bad air temp sensor. After replacing the Air Temp sensor the engine ran perfect.

The dealer also filed all of the paper work with GM.

The conversion was very expensive

I think it may be wise to really add up all of the cost involved. It may be cheaper for you to stay with a 305.

moreyes

I can see why you spent so much money. I already have a guy who will burn the chip for me. I have the pre 87 TPI so it matches the head bolts on this engine. I don't really care about upgrading the computer at this time. The 85 computer on the vette tpi and the f-body tpi were the same only different proms. How much did you pay for labor? they are charging me 800 for the swap. Headers and a better cam would make this a pretty good engine


24 pound injectors = $200
labor= $800
motor= $1650
prom=$100 or less

five7kid

iTrader: (14)

Factory 350 injectors were 22 lb. With this engine, the likelihood of needing more than 19 lb. is slim. Put on an adjustable fuel pressure regulator while you're at it, it will be fine with the 19's.

The heads on that engine are going to limit any upgrade potential. If you're thinking of a different cam, that's the time to take your 305 heads and have them worked over (1.94" intake valves, basic porting, rocker studs anchored, new valve springs). That will bring the compression back up and provide more flow capability than the heads that come on the crate engine have.

In fact, an alternative to consider is an L98 shortblock. Put prepped 305 heads on it, nice TPI performance cam, headers - even better engine for no more money that you'd end up sinking into that crate.

RB83L69

Why pick only one? You could have the worst of both worlds!

Air_Adam

I remember that! LOL... that guy was selling it as a "hi-rise 4bbl intake" hahaha...

moreyes

Thats actually a good idea Kid.

Friend suggested the 12-268-4 or 12-262-4 comp cams tpi. I got 50% discount on labor and parts at a local shop that can do the machine work for my heads. Can you go on ebay and look up the short block you are talking about for me? I want to get an idea of how much would that option cost.


UPdate: The guy from the shop told me not to waste time and money on 305 heads and get vette aluminum heads

moreyes

i found a site that sells the same long block for $400 dollars cheaper plus they can build a cam to your specs for $200.

80-85 chevy 350, 2 bolt. non roller long block with 882 casting heads and flat top pistons.
Comp cams 12-262-4 cam specs:
Duration at .050: 218
Intake Valve Lift: 0.464
Exhaust Valve Lift: 0.47
Lobe Seperation: 114°

what do you guys think?

RB83L69

EEEeeeeeewwwwwwww

There's alot more to long block selection than just picking the cheeeeepest one.

What parts are in it? What pistons especially? Do the rods have new better-than-stock bolts (the part that breaks)? How was the machine work done? What was checked? Time = money, you know; any doof can sweep up a bunch of parts off the floor, slam them together, and sell them cheap; is that what you want for your "project"? a DOWNGRADE?

Power lives in the heads. If there's any ONE SINGLE part that limits the performance of the engine, it's the heads. You can have a bottom end forged of pure nonbtanium in the fiery furnaces of Hell by 10,000 year old gnomes, and a custom cam ground on a billet irreplacium blank; put a set of 882 castings on it, you've got a pig.

I have paid people to haul off piles of 882 castings to be melted down. I sure as hell wouldn't pay somebody to ship me a pair of them.

I'm not a big fan of TPI; but I'm even less of a fan of the idea taking a Jeffrey Dahmer saw to a car and just hacking it to bits because I don't understand something. I'd suggest keeping the TPI, and finding a short block that's built out of AT LEAST as good parts (HEADS HEADS HEADS) as a STOCK 350 TPI would have come with. With that induction system, it's amazingly easy to throw a crap 350 together (such as with 882 heads) that will make less power than a stock 305 TPI did. About the best way I can think of to get that result, is buying the CHEEEEEPEST long block (HEADS HEADS HEADS) I can find, without any concern for what it's built out of.

moreyes

Damn,
I didn't know they sucked that bad. A friend told me they were the better flowing heads for pre 87 style. What would be "good heads" with the pre 87 bolt pattern? How can I even get my 85 tpi on newer style heads? Do they sell a intake manifold with the newer style pattern so i can put the older tpi on it or do i have to stick to pre 87 style heads?

How about this short block? http://cgi.ebay.com/ebaymotors/ws/eB...category=33615

RB83L69

Looks OK, as far as it goes; although it doesn't say if the rod bolts were replaced. So they probably weren't. Same for torque-plate honing.

I wouldn't use a HV pump on a street motor. It has no benefit, and has the disadvantage of higher loading on the distributor gear.

The cam he's quoting is amusing: it's the EXACT SAME GRIND as the "Performer RPM", except you can probably buy it the way he did, for at least $80 less than Vic charges. But that doesn't matter, because you'd have to change it for TPI anyway.

If you can establish that those first 2 things were done, and get him to put a standard M55 oil pump with the Mr Gasket 26 spring in it instead of the HV, it might be OK. Then, see if he'll put some other cam in it, that's compatible with TPI. The more suitable cam will cost extra, but should be no more than $75 different or so.

For heads, the easiest best ones to get that you could pick up fairly cheap, would be the ZZ4 / Vette L98 aluminum ones (113 casting). Then at least you'd be on a par with a stock TPI setup. The only other heads that would NOT be a downgrade to a stock 350 TPI, would be old double-humps; which isn't really a good idea, just for cost-effectiveness reasons. Some of the 305 heads would be OK, including the ones that would have come on your 85 TPI 305 (416 casting), but IF AND ONLY IF they have larger valves installed in them and some port work done.

TPI is such an inflexible rev limiter and power limit, that you don't need a bunch of expensive bottom-end stuff; stock rods & crank are fine, when properly prepped. The induction will protect the short block from ever seeing any stress exceeding (or even approaching!) the short block's design limits. You don't want to get stuck with a bunch of chinesium pistons though. That's a recipe for a short-lived motor that begins burning oil and experiencing massive blow-by early in its life. It sucks to spend $200-2500 "rebuilding" a motor, only to have it reach the geriatric stage in 20,000 miles; by that time, you will have long since forgotten about the $50 you saved on the cheeeeeep pistons.

It's pretty depressing to "save" $100 or even $500 on a motor purchase, and then have it pop about 3 days after the warranty expires. Kind of makes that up-front couple of coins look not so important any more.

moreyes

I'll find that out RB.

What about the bolt pattern for the newer style heads? Can I drill my manifold or should I buy a new one?

BruceEmbry

I paid only $600 labor.

I have about 55,000 miles on engine. I use Mobile 1. No problems.

moreyes,
While I may agree with these other guys that the engine is not the best performace option, you will be surprise of how much power that this engin does make with the TPI intake. My motor makes power all the way up to 5000RPMs and beyond.

Hay I'm running a 2.73 rear end and can easily smoke both tires.

It all depends on what you want to be able to do with it. If you want dependable daily then go for it. If you want more power you should consider one of the other GM performace crate motors. Its funny how everyone will suggest ways for you to spend your money.

moreyes

Didn't the stock 350 tpi make like 230hp?

BruceEmbry

That may be the correct number for an stock L98.

I don't know what horsepower my combination makes. But what I do know that it has plenty. And it lot more then the stock 305 TPI I think the stock 305 TPI is L09 engine code.

Sometime assembling parts into a system, such as selecting intake, cam, heads, etc, can be a crap-shoot. You will not know what you have until you crank it and go down the road.

I do not have the most powerful setup in the world, but I like what I have. Its depenable, fun to drive, and not very expesive to maintain. Its no longer my daily driiver. I do not race.

Like I siad above, if you want more power go with one of the other GM Performace Crate engines. There are made by GM and will more dependable then any shop can build up. My motor came with a 50,000 mile 3year warrenty.

moreyes

RB

I got an email back from the guy and he said to look and this other SB it has new ARP rod bolts and is a 4 bolt main http://cgi.ebay.com/ebaymotors/ws/eB...category=33615
He said he doesn't have a problem using a standard pump with your requested spring and a tpi computer compatible cam free of charge. Torque plate honing would be an additional $75.00

BruceEmbry

You have got to be kidding. ASE CERTIFIED MACHINIST are a dime a dozen. Big mistake buying most stuff off of EBAY. No warrenty, etc. And no way to trace the sellers down when they live on the other side of the country.

moreyes

i see your point Bruce. He has really good feeback though. He has sold several SBs