pre '86 305 TPI super charger?

[Mathius]

Does anyone make one? I heard Paxton used to. I have a 305 TPI from an '85 Pontiac.

What sortof precautions should I take with a supercharger? I was going to have the block rebuilt anyways. Should I have anything special done? It isn't for a daily driver, but I don't want the block to fail either.

Mathius

[Texas Hotrod]

Paxton used to. What about Pro-Charger? I'm sure that there are others that make similar units.
You're building a 'charged 305?
Bigger is better, use a 4-bolt 350 block and build up a 383 if you can afford it.
How much power are you looking for? What boost do you plan to run?

You're driving the blower from the front of the crankshaft. A stock crank won't take the abuse. Start out w/a balanced rotating assembly from Skat and upgrade to D-cup pistons (for blower use). You'll need a great set of heads and a mild rollerized cam.
You are pre-TPI, so it has a Q-jet? Install a Victor Jr. and get a Holley HP series carb from CSU and build a blow-through system. You won't need an after cooler but you will need a meth/water injection system. You will deffinately need an MSD timing computer (BTM). Quality parts and a matched package, 800hp is easily obtainable.
More power means other problems. You'll have to beef up the tranny and swap in a heavier axle.Then there's frame stiffners and traction devices. Better brakes, racing harnesses, roll cage, etc...There seems to be no end to what's needed when you start making power.

You need to come up w/a budget and price everything out. You can easily spend $12/15K.

Or you can stick a Pro-charger on the tired old 305 and see what she can do. Keep the boost low and the timing retarded. Once you do that, you'll get hungry for more. Once she blows, you can build a real engine.

Keep us posted on what you do.

[Mathius]

I'm just checking my options right now. I can probably buy a crate motor 350 for about the same price it will cost me to rebuild the 305, and the 350 has potential to put out more power, both true.

But I want to do something different, and this still might be my most cost effective method.

Other ideas were a 496 from a Silverado, fuel injected 454 (maybe the merlin-x World all aluminum block), but both will likely be far more expensive. I also have a 4.3L v6 in the garage complete with tranny, but I don't think it'll haul my 4000lb Malibu.

And no, I'm _not_ pre-TPI. I have a TPI unit off an '85 Pontiac (firebird or trans am, not sure) F-body.

I don't know how much boost I can run. Not crazy about running high octane gas unless I have no choices, and I don't know much about super charger's right now. (thus why I started this thread)

Block has just over 50k on it, original. Car has full frame. Stock axle, but I think I'm gonna upgrade to a 9". Car is a '76 Chevy Malibu. Currently I'm working on the body. Started a floor pan install last year before I expected the weather to hit. Never finished, due to a move.

So now I've answered your questions, can we get back on topic? What's available and what do I have to do to my block?

Mathius

[Turbo Hen]

Whoa................easy there Mathius.

If you'd like to do something "different" i suggest a turbo system using a carb :)

[Mathius]

Whoa................easy there Mathius.

If you'd like to do something "different" i suggest a turbo system using a carb :)

I don't like carbs and I asked about a super charger.

Thank you.

Mathius

[Mathius]

Well so far all I got were two guys trying to talk me into using a different setup.

Can anyone actually answer my questions?

Mathius

[TPI Monte SS]

I think the only reason they list it for '88-'92 cars is that's when the F-body used a serpentine belt assembly, so the bracketry is completely different for a '87-earlier car. As long as you use the factory F-body serpentine brackets, you should be able to use the supercharger.

Again, if you're gonna run it on a stock bottom end, keep the boost low and make sure it's got enough fuel. A friend of mine had a bone-stock bottom-end '88 305 TPI IROC that he put one of the intercooled ProCharger setups on, and it ran a 12.99 with a 6-speed and 17" street tires.

[Mathius]

I think the only reason they list it for '88-'92 cars is that's when the F-body used a serpentine belt assembly, so the bracketry is completely different for a '87-earlier car. As long as you use the factory F-body serpentine brackets, you should be able to use the supercharger.


Actually, GM changed head bolt patterns in '87, so unless it uses the stock manifold, it won't bolt up. Pretty sure it won't.

Mathius

[Turbo Hen]

GM did not change the head bolt patterns in '87, what they did change SLIGHTLY was the angle of the 2 bolts in the center of the head, where the intake manifold attaches. This can be slightly overcome by clearencing the intake manifold (grinding a slot) and you'll be able to bolt it on.

Thank you.

-Carm

[Texas Hotrod]

Well, I don't think Mathius' question has still been answered.
I think we all agree on one thing, though. It's a waste to spend so much effort on a 305 (not to hurt your feelings, or anything). The 305 has the same stroke as a 350, but w/smaller bores. Performance heads are almost nonexistant for the 305 because the intake valves have to be kept small (because of cylinder interference). A 2.02 valve will not work in a 305 application. I could be wrong, but there are limited choices in performance pistons as well. A 'charged motor needs low compression and D-cup pistons are the best choice. All I can say is to see what Jeg's offers and go from there.

To use your 305 block: Have a set of billet main caps installed and get a performance crank/rod set. Cast steel cranks are better than the stock nodular crank and are relatively cheap ($189?). Going with H-beam rods and forged pistons? Might as well get a balanced rotating assembly, if it is actually available for the 305.
Have the block bored and honed w/torque plates, but keep decking to a minimum. Just enough to have it cleaned up. If you plan on running respectable boost levels, the the block would need O-ringing.
What are your plans for heads? You don't have to concentrate as much on the intake side compared to natural induction, but getting the exhaust out is of great importance. 305 heads that have 194 intake valves don't leave any extra room for 1.6 exhausts. So you'd be stuck w/1.5s. For the cost of modding a set of stock heads, a performance set could be bought.
Any plans for an intake? TPI units are really restrictive, but should work ok (not great) for a pressurized system. The ultimate manifold would be a Victor Jr. and have the runner bosses drilled for fuel injection. You could easily adapt a Vortec throttle body to the top of the Edelbrock and then pipe the charger to that. The TPS sensor is different, so a pigtail would have to be wired in.

It's cool to be different, I agree on that idea. When it comes to making power, bigger is better. As I said in my original post, build a 383 and then you'll have something. 800 HP would be no problem. 1K HP is no sweat w/a charger (easy w/turbos) and a blow-through carb, there's lots of technology in that old (low tec) set up. DFI can get those #s too, but far more complex and a pain to tune. TPI electronis couldn't support anything close to that and it would be the limiting factor.

If you are stuck on using the 305, then have the block bored to a 1st over set of forged pistons and replace the stock valves w/stainless pieces. Stud the heads and use Felpro performance head gaskets. Install the stock TPI w/30lb injectors, tune the fuel regulator, get the required ecm chip and wire in an MSD BTM. Like TPI Monte said, 12.99 would be possible. Pathetic, but possible. Wouldn't the potential of high 10s be more impressive? I've seen Hen's vids and his car really scoots.

A charger on a 305 would be cool, so build it if that's what you really want. Or be patient and build a true monster. Keep one thing in mind, being waxed by a typical 5.0 Mustang wouldn't be funny. Blowing away all (or most) Mustangs that put up a challenge will make it all worth while.

[TPI Monte SS]

Actually, GM changed head bolt patterns in '87, so unless it uses the stock manifold, it won't bolt up. Pretty sure it won't.


True, if you're talking a Roots-style blower. However, he's talking about a Paxton TPI supercharger kit, which is the one that is mounted off the serpentine brackets, and has an elbow that feeds incoming air into the TPI throttlebody. Intake base boltpattern won't matter in that instance, since the throttlebody is in the same place for any TPI motor.

[Mathius]

GM did not change the head bolt patterns in '87, what they did change SLIGHTLY was the angle of the 2 bolts in the center of the head, where the intake manifold attaches. This can be slightly overcome by clearencing the intake manifold (grinding a slot) and you'll be able to bolt it on.

Thank you.

-Carm

Actually, you are correct. I knew there was something different about the heads, because I had to locate a pre 86 set when I looked for the TPI. I just didn't remember correctly when I read this post.

I had read there were guys that were adapting the newer intakes, but it always seemed to me like a risky operation. Isn't that a pretty easy way to ruin a prefectly good manifold if you screw it up? Or create potential leaks?

Mathius

[Mathius]

True, if you're talking a Roots-style blower. However, he's talking about a Paxton TPI supercharger kit, which is the one that is mounted off the serpentine brackets, and has an elbow that feeds incoming air into the TPI throttlebody. Intake base boltpattern won't matter in that instance, since the throttlebody is in the same place for any TPI motor.

So I'm not sure I understand. Are you saying the Paxton kit hooks up where the throttle body is located, and doesn't actually replace the manifold? I'm not familiar with this setup.

Mathius

[Mathius]

To use your 305 block: Have a set of billet main caps installed and get a performance crank/rod set. Cast steel cranks are better than the stock nodular crank and are relatively cheap ($189?). Going with H-beam rods and forged pistons? Might as well get a balanced rotating assembly, if it is actually available for the 305.
Have the block bored and honed w/torque plates, but keep decking to a minimum. Just enough to have it cleaned up. If you plan on running respectable boost levels, the the block would need O-ringing.
What are your plans for heads?

Don't have plans as such. I've heard that 55cc heads are good for building power, and came on early 80's model Chevy vans. I guess with some porting, they put out decent flow.

Read quite a bit here: http://www.thirdgen.org/techboard/tech-general-engine/239455-305-build-up.html?highlight=tpi+super+charger

And a bit on porting and polishing here:
http://www.thirdgen.org/techboard/tech-general-engine/117410-305-port-polish-pictures.html

Again, I don't have any "plans" of yet. I'm trying to figure out what I should do. I'd like to get my engine taken care of this summer, and get some new wheels and tires on it, so I can at least have it on the road, and then work on it from there, upgrading the suspension, and continuing the body work. Seems a waste to not use the TPI setup I got, and I don't think the resale value on a 305 is going to be particularly high, so it might be in my best interest to just do something with this block. And anything I do to a 305 will be unique. Not too many people building them.

Mathius

[Turbo Hen]

You wont ruin the intake by slotting it......some aftermarket intakes comes like that like the one i use.

No leaks or anything.

I think O-ringing a block is something of the past......MLS gaskets are here to stay & they are the replacement to O-rings. Lots of people out there without o-ringed blocks (myself included) and they work just fine.

-Carm

[TPI Monte SS]

So I'm not sure I understand. Are you saying the Paxton kit hooks up where the throttle body is located, and doesn't actually replace the manifold? I'm not familiar with this setup.

Mathius

Now I'm confused. You stated you wanted to keep the TPI intake. How were you going to use the TPI if you were planning on replacing the manifold??? The TPI IS the manifold.

Anyway, take a look at this link - http://www.rpmoutlet.com/atifbodytp.htm

Don't let that particular intake fool you, that's a Miniram intake, instead of the TPI. The supercharger is mounted off the driver side bracketry, next to the alternator. You need a factory serpentine belt system for the accessories (alternator, AIR pump, AC compressor) to run this type of supercharger AND keep the TPI manifold.

[Mathius]

Now I'm confused. You stated you wanted to keep the TPI intake. How were you going to use the TPI if you were planning on replacing the manifold??? The TPI IS the manifold.

I was thinking of a different style supercharger, the one with the large crank on top that drives the big belt. Is this a roots style?

Anyways, TPI is not just the manifold. If you swap the manifold, you still have to have it be compatible with the TPI computer.

But I will check out the link you sent in a bit.

Mathius

[TPI Monte SS]

I was thinking of a different style supercharger, the one with the large crank on top that drives the big belt. Is this a roots style?

Yes, and there's usually a carb on top of that.


Anyways, TPI is not just the manifold. If you swap the manifold, you still have to have it be compatible with the TPI computer.


Agreed. If you check my car out (see link in my sig), you'll see I'm a bit familiar with TPI. I'm no expert, but I've got a factory '87 Camaro TPI harness and computer mated to my '88 Monte SS, and the ALDL and Service Engine light work properly. Let us know if we can help further!

[Texas Hotrod]

This is my roots blown car. When people ask about it I usually comment that it came from a dump truck.
It's actually a Detroit Diesel (General Motors) unit that was on a 2-stroke, 6 cylinder diesel engine. The case and internals is all GM, but everything else came from BDS. From paint/body work, building the engine/tranny to piecing together the blower and building the DFI system, I did it all myself (one of these days I'll find a perfect grille).
The engine is a 406, and the torque is unreal. A big block would have been even better. The pulleys truely do sing at highway speeds. Only a turbo (turbos) can match that sound.

The Paxton unit looks like a big AC compressor and are referred to as a "super charger".

So you want to install a "blower"?