4door!cutlass

455,Bored. 40 over,mild cam upgrade.moter was rebuilt stock other than cam.moter came from a 71 delta 88.400 trans with v6 rear.stock q-jet carb.
So anybody know about what horspower i have .

billmerbach

I'd estimate about 3 to 400

4door!cutlass

Yea but that's a wide margin

billmerbach

That is true I have a book in my book bag that has them specs for the base HP I'll have to get it out.

4door!cutlass

Yea but that's a wide margin

4door!cutlass

Cool !

J-(Chicago)

250-275 hp

3-4 is off. The L77's barely made 300

droptopron

It's hard to say it was rebuilt "stock" when you know at the very least the pistons were changed.

I think compression in '71 was about 8.5:1. Do you know what pistons were used in the rebuild?

4door!cutlass

That's the million dollar question,i have no idea what size pistons were used.
i forgot to mention i have g_heads.

4door!cutlass

4door!cutlass

The range from 320 to 400 horsrs .
where u get 250 from?.

J-(Chicago)

That's what they claimed, but in reality it was around 8.1

joe_padavano

The real answer is that real world HP will always be less than you think. The factory numbers were suspect at best (again, how did the AT W-30 motors make the same HP and torque as the MT motors, despite a much milder cam, or how did the Toro motors make more HP than the W-30 motors with a milder cam, more restrictive intake and exhaust, etc?). The only way to know for sure is to either put the motor on a dyno or run the car at the track and back out HP from your ET and vehicle weight.

4door!cutlass

71

J-(Chicago)

http://en.wikipedia.org/wiki/Oldsmobile_442#1972


There is absolutely zero difference between a 1971 and a 1972 455 unless it was a 1971 w-30 car with H heads.
Some people were lucky and received heads with bigger valves. I have a pair of 71 442 heads here that were big valve models. With 8:1 compression, I imagine it helps, but not very much.

J-(Chicago)

I'd pull a spark plug and look in the hole to see if the pistons have a big dish or not.

If they look like this, you're probably doomed.

4door!cutlass

4door!cutlass

Ok,i will

455man

I'd look at a pic on the net of shallow pistons and deep dish pistons so you have something to gauge when you look in the spark plug hole. Any idea on what cam was put in?

J-(Chicago)

here's a pic of a hi comp olds piston.

4door!cutlass

No idea

4door!cutlass

4door!cutlass

Hope not,let u know. this afternoon

Fun71

So you have no idea of the compression ratio or the cam specs. The best anyone can do is give you a guess based on a number of assumptions, and I think J-(Chicago) has probably given you a realistic number.

4door!cutlass

So what u know,i have the high compression. pistons.i can't see very much. but i can see its a bell shape , like the first high compression photo.
so now what does that tell us.