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1987Regal
02-15-2005, 03:22 PM
In the near future I'm planning on building a twin turbo small block Chev for a 1987 Buick Regal. Now for the questions. I need to know if a good old regular Chev 350 4 bolt main will work for this kind of power or do I need to run an aftermarket block? Next, once I have the block what do I use for internals to withstand this kind of power. I'm looking upwards of about 800 horse. Any advice would be greatly appreciated.

Also....what should I use for turbos? I have seen posts about aftermarket turbos down to turbos of big rigs and turbo pickups.

andrewb70
02-15-2005, 05:57 PM
Rating internal engine components by HP is a little misleading. It's really not the HP level that kills parts. It's improper tuning (burning pistons) and high RPM (rods, cranks) that kills parts. So as long as you keep your revs to a reasonable, under 7000RPM limit, any good forged rotating assembly will do the trick. For extra protection you might consider pistons that are designed for forced induction.

As for turbo selection, there are many good resources on the internet that can guide you along. The questions is way to broad to answer in one post. There have been books written on it.

Andrew

shmoov69
02-20-2005, 06:07 PM
What he said!!

WELTERRACER
02-25-2005, 06:07 AM
Stock SBC blocks are good up to 900hp as long as you have good ARP bolts... like said before, any forged crank and rod will probobly hold up to 900hp

TurboLark
03-03-2005, 06:50 AM
Use the 4 bolt if you want to, but for peace of mind, get a Dart, World block. A good forged crank and rods with good bolts. Keep compression down to around 8.5-1. Get a custom cam made.
There are too many variables to pick turbos for you. HP goals, rpm desired, street/drag/road course.
Go check out the forums at www.turbomustangs.com there is a specific GM forum there. Lots of very knowledgible turbo guys.

majik16106
03-09-2005, 08:07 PM
you can get all kinds of good info from some of the smarter turbo import guys too, a lot of those guys know a ton about reading out compressor maps. They are right, too broad a question, tons would work, what is the purpose of the car. i mean, i'm building sort of an all around car, in which i mean its a little too much motor for anything.. haha. you want forged internals, figure try to get out of it at around 65-6800. im using solid roller lifters so i get no float. 230ish cc runners in the heads and manifold. and your fine up top, fuel injection is smart, but not neccessary, figure atleast 60ish lb/hr injectors. im using a 350 bored .030 over. stock rod length, stock crank stroke. with twin t04e turbos, .57 trim, p trim wheel, about a 69 a/r. with that and an intercooler, your lookin at 450-550hp at 12-13 psi, and at 17-19 your looking at 8-900. and you can do that on pump gas. put some race fuel, make sure tuning is dead on, run her up 23psi, your lookin at 1000+, at the 17-18psi mark your lookin at full boost about 3600rpm. there is a general build and with some general round about numbers.

myclone
03-10-2005, 12:39 AM
In the near future I'm planning on building a twin turbo small block Chev for a 1987 Buick Regal. Now for the questions. I need to know if a good old regular Chev 350 4 bolt main will work for this kind of power or do I need to run an aftermarket block? Next, once I have the block what do I use for internals to withstand this kind of power. I'm looking upwards of about 800 horse. Any advice would be greatly appreciated.

There are probably as many opinions on the above as there are ways to build a SBC and so far everyone has provided sound advise IMO. I'll throw my .02 in the mix FWIW since Ive seen some turbo motors disassembled that were using some of the components you mentioned.

An early 90s production cast cranked (crank cryo treated), Eagle H beam rods, two bolt main block with ARP main studs and nodular iron main caps had signs of main cap movement at the 600hp mark. This was on fairly low boost of 15psi and a good tune (no detonation to speak of).

The same block was remachined for production style four bolt mains, reassembled, and was on the way to 800hp when a cracked cyl wall stopped the dyno pull. The block was sonic checked before boring (.030 over) but IMO there was a casting flaw that propogated the crack which sonic checking wouldnt have shown. Anyways, upon disassembly the mains didnt show any evidence of movement but then again the motor wasnt leaned on for very long before the crack in the cyl developed.

Next was a late 80s (89 I think) production block that was machined for splayed four bolt mains and the main caps were from Program Engineering. The rotating assembly was transferred from the above engine to this block and it made 920+hp and just under 800ft/lbs on the dyno without so much as a whimper and is going strong in a street car as we speak. Could it scatter tomorrow? I guess it could but we leaned on it harder than it will ever be when it was on the dyno and upon disassebly to assess any wear the rotating assembly and bearings looked good as new.

An aftermarket block is the way to go for piece of mind if you dont have any issues with the added cost but then again those pieces are of superior quality and will prolly last a life time at your 800hp goal with a good tune. A production block is deffinately cheaper but you may go through a hand full of cores to find a good one which isnt free unless you own a machine shop and once you do find a "good" one there is still the possibility it could scatter all over the dyno room.

To sum it up a production block is a capable piece with some work and some expense that wont break the budget but an after market block, while more expensive up front, is one of those deals where you can just about abuse it as much as you want without crossing your fingers that you wont carry it home in a five gallon bucket.