Check out my car in my sig.

I'm thinking of a procharger for my car.
However, I do NOT want to touch the heads, crank, rods, or pistons. The car has 90,000 miles. Bad idea? hehe

The only thing I really plan on doing is the fuel pump and 24lb injectors..

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92 Formula
305 TPI 5speed
1LE package
Mods: SLP headers,SLP catback,SLP air foil,ported plenum,K&N, Crane AFPR (47psi),MSD6AL, MSD wires, AC DELCO cap/rotor/plugs, Bosch O2sensor, 3:73s,JET fan switch, Macewen white face gauges, Intellitronix Digital Gauges

 

Take it from experience and rebuild your engine before supercharging. Its a time bomb and beleive me installing a procharger is no walk in the park. You wont need the 24lb`s and the fuel pump is part of the kit. My ride only had 65000 miles and it didnt last a week. Good luck.

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88GTA 5.7(under construction) ATI Procharger,58mmTB,ported plenum,SLP runners,Edelbrock HI-FLO base.ported heads,1.5RR,210/220/480 compcam,AFPR,SLP1 3/4 headers,3.70 gears,Eibach drag launch,Lakewood LCA`s, Nitto drag radials.

 

OH my god. It didnt last a week?

Dayummmmmmmmmm

What exactly happened bro?

 

I ran it rich like the instructions recommend and the Edelbrock intake I used caused my in jectors to bind. Too much fuel and since my cylinders already had some blowby cus of the miles fuel seeped down to the oil pan and thinned out my oil. **** happens! Oh well I ordered a 383 blower shortblock should be here in 3 weeks. I should have done this in the first place.

 

Well that wasn't really a "blower problem" that was a "tuning" problem. If you wash the cylinder walls down from an overly rich mixture, with or without a blower, you will junk it. Even a fresh rebuild or a new engine would surely suffer the same fate. I know many people (including myself) That have installed superchargers and/or nitrous on high milage motors without harm. The bottom line is if the "tune is correct and the engine is sound, a supercharger or nitrous in moderate quantities won't hurt it.
If your engine has good oil pressure, has no unusual noises, and doesn't smoke it is a good canidate for supercharging. If in doubt do a compresion check, or better yet a leakdown test. If the numbers are good charge away.

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• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo

 

You are absolutly right Irock . My problem was not a blower problem. However, every high milage engine will have some cylinder wear especially a 90000 miler like our bro here. And with the increased cylinder pressure it will be a time bomb waiting to go off. Now it my last with proper tuning but on an ATI the tuning process is grueling. By the time its tunned there may be nothing left to take to the track. Thats one reason I recommend rebuilding before supercharging. The other is because of the work and cost involved in tearing down a TPI motor. I would just hate for anyone to go through what I went through and find out too late what they should have done in the first place. Kinda like what happenend to you with your tranny situation.I hope this helps.

 

Thanks for all the replies guys I really appreciate it.

Transformer,
You said high mileage engines cylinder walls can wear therefore increasing cylinder pressure....Does this in turn increase compression? Meaning worn out cylinder walls increases your compression. And with the extra boost it means "bye bye 305?"

Did i get that right or am I way off?

Why is the ATI tuning procedure grueling? I plan on running around 6lbs of boost. Should I go with another brand?
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92 Formula
305 TPI 5speed
1LE package
Mods: SLP headers,SLP catback,SLP air foil,ported plenum,K&N, Crane AFPR (47psi),MSD6AL, MSD wires, AC DELCO cap/rotor/plugs, Bosch O2sensor, 3:73s,JET fan switch, Macewen white face gauges, Intellitronix Digital Gauges

[This message has been edited by theformula (edited December 10, 2000).]

 

I'm sure that Transformer was saying the increased cylinder pressure {created by the supercharger} would compound the problems created by the potential wear on the engine. Worn cylinder walls and/or rings will decrease compresion and cylinder pressures and may also allow engine oil into the combustion chamber which will reduce the octane of the fuel mixture and in turn increase likelyhood of detonation. However, a moderately high milage TPI motor may, or may not be worn out! I have a friend with an '88 IROC-Z with around 65000 miles on the clock. It is hard to start (it floods), and when he finally gets it started it runs like crap, black smoke rolls, and his MPG is bound to be single digits. He at east has a/some leaky injector(s). The bad part is that the car was like this when he bought it early this summer (& who knows how long it has been like that before he bought it?) and he hasn't fixxed it yet and he runs the wheels off of it. I'm sure the rings & cylinder walls are shot now. A port injected motor will ruin cylinder walls quickly if too rich because the fuel will spray past the intake valve into the chamber and coat the cylinder walls & wash off the lubrication oil in the hone marks. That lack of oil will wear out the hone marks on the cylinder walls and eat the rings quickly. However, a properly tuned & maintaned port injection system will meter fuel accurately and reduce upper engine wear. The better fuel distribution and atomization (when in proper tune) of a TPI system will allow longer engine life than the carbs of the old days. I can remember when any engine was pretty much completely junk by the time it had 100,000 miles. These days that is the first tuneup interval. On a lighter note, The original 305 that came out of my car at over 81,000 miles (in favor of a built 355) had excellent leak down rates (indicating excellent ring seal), had no ridge at the top of the cylindera and the hone marks on the walls looked brand new. There also was no scuffs on the piston skirts and no carbon build up in internals. I atribute a large portion of that to the TPI system working so well when carefully mantained. Aso to religous oil changes. I owned the car for most of its existance and I knew the previous owner (he bought it new & had it less than 1½ years before I bought it).
If in doubt, do or have a leak down test done. That will tell you the condition of each cylinder. The engine doesn't have to come apart for that. If it's bad you need a rebuild. If not you don't. If your stuff hasn't been abused or neglected and is in good shape it should do fine. I am not always keen on "doing a rebuild just to be sure". If you aren't already "sure" if you need it or not you might mess up more doing it. I know of lot's of engine rebuild horror stories. Things happen. Poor quality rebuilding practices and misinformation can ruin an otherwise good project. Poor communication between the customer and engine builder (if/when you don't do your own) can happen. I've got a buddy with a fourth gen TA with a 383 + vortech supercharger. I forget which builder he went to first but it was either Lingenfelter or Calloway. He had an engine built but neglected to tell them he intended to later install the Vortech. The compression ratio on his professionaly built 383 Lt1 was too high for a supercharger. He detonated and smoked a brand new $15,000 engine. Of course it was his fault and the builder was not to blame. He went back to them for another build and they where backed up with orders. He then went to the other builder and got another engine built for another bunch of $$,$$$$(this time a purpose built blower motor with lower compression.) No problems now and hes been running it for years. The point is, "Sƒ©ß can happen even with a rebuild." Sometimes your better off without. Bad things can happen either way. If you really don't want to do a rebuild you might not have too. But if you put a supercharger on a motor that is already living on barrowed time it's done!
See if the dipstick is clean. Make sure it doesn't knock (particularly at startup.) Make sure it doesn't burn oil (smoke). and have a compression & leakdown test done. If everything is good you should be set. After installation be sure to check timing & air fuel ratio. Both have to be "dead on" even on a fresh built engine. Too little timing will cause problems. Too much timing will cause big problems quickly. Too much fuel will cause problems. Too little will cause big problems quickly. Your cooling system will need to be up to par too.

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• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo

 

That was beautiful...i'm **** for words right now..


Only one question, how and what is a leakdown test?

Thanks Iroc.

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92 Formula
305 TPI 5speed
1LE package
Custom cold air intake w/K&N, SLP airfoil, ported plenum, Crane AFPR (47psi),MSD6AL, Holley 9mm Annihilator wires, Ac Delco cap,rotor and plugs, Bosch O2sensor, Slp 1 5/8 headers and catback (all stainless steel!), 3:73s,JET 195* fan switch, Macewen white face gauges, Intellitronix Digital Gauges

 

I had put the blower on the car at 68,000 miles. I always wanted a larger motor, but I figure I will wait until the motor broke. 2000 miles later a 383 was born.

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'91 Formula
383CI Supercharged
5-speed
3.42
12.34@117.04
on Drag Radials

 

It is kind of like a compression test. You will need a tool called a "leakdown tester", "cylinder leakage checker" or "cylinder leakdown gauge". This tool usually looks kind of like an aluminun stick with two compression guages mounted on it. You also will need access to a compressed air source. You remove all the plugs. You test each cylinder one at a time. You rotate the engine until the cylinder you are testing is at top dead center of it's compression stroke. You hook up the test guage to the spark plug hole, then hook up the compressed air to the regulator on the guage. Apply air pressure. The amount of leakage will show on the guage. You can tell what is leaking by listening for where the air is leaking from. If it is leaking back through the intake manifold then the intake valve is leaking. If it is hissing out the exhaust, the exhaust valve is leaking. If it is leaking into the radiator (& you hear/see bubbles in the coolant) the head gasket is leaking between the combustion chamber and water jaket. If it is hissing from any of these points in another cylinder than the one you are checking at the time then it has a leak in the head gasket between cylinders. If it is leaking into the crank case and you hear hissing from the oil fill cap on the valve cover then that is normal. A small percentage of leakage of this type will occur in any engine. The guage will tell you how much leakdown is occuring. It should only be a small percentage.


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Tracy /AKA IROCKZ4me

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo