Re: Chevy - overall thoughts on the 327?

what's the bore and stroke on the 5.4 ?

the 'old 327' (60's) was 4.000 x 3.25

I'd bet the 'new 327' is probably 3.8-something by

My new Avalanche has a 5.4 liter motor; whereas my Suburban and Yukon have

> a 5.7, and my Sierra 3500 has the 8.1. Although it would be unfair to
> compare the 5.4 to the 8.1; I am of the impression that my 5.7 engines are
> *noticeably* more powerful than the 5.4. I would describe my 5.4 as
> "gutless"; a term that I thought deserved to die in the mid 70's to early
> 80's. How do other folks feel about their 5.4's?
>
>
>

The GM 5.3/327 is 285 HP, 325 lb-ft. bore and stroke is 3.78 x 3.62

Mine runs strongly, so I don't think I have a lame motor; but it's just gutless. I have to mash the accelerator to the floor just for it to hold 80 on the highway if I am going up an incline. BTW, I keep it in 4 auto, so all power should be going to the rear wheels. My Suburban and Yukon with the 350 have markedly more acceleration, IMHO. Now before you tell me the 350 is a more powerful motor; the GM 5.7/350 is 255 HP and 335 lb-ft; which is about the same animal as the 327. And my Burb and Yukon probably weigh more than the Avalanche, so you would think that the Avalanche would perform much better than the Burb.

That's what I meant, too.

jesus, mary, and joseph, that's worse than I thought

hells bells, the Olds 307 was 3.800 by 3.38, and it was a 'Grandma's Car' engine

yep, and the old 327 had 1.8:1 bore/stroke ratio which is ideal

Chevy is listing it as a 327. Are you sure it's 325? Did you get that from the 5300, because the engine is actually 5328 cc's.

Dave

Do the math.....

Cubic Inches = .7854 x number of cylinders x Stroke x Bore x Bore

I get 324.9 CID

Dave

I apparently know more than you - I called it a 327 and not a 325. :-)

On paper my 03 327 has more HP and torque than my 00 Yukon 350 or 99 Suburban 350; but my Avalanche is quite a bit slower than either of those two.

Definitely gets about the same gas mileage. About 14.6 over the first 5,000 miles for the 03 Avalanche (90% highway miles). My Suburban does about 16 on the highway (give or take).

That could take forever - I am using Mobil 1 in the vehicle.

My owners manual references it as a 325. BTW, the link you provided doesn't seem to be from GM.

Should cuts in

calculation?

I think that would only affect compression ratio.

Dave

hobbes,

CID = # of cyl X .7854 X Bore X Bore X Stroke

-Bret

the formula came from the back of Edelbrock's catalog.

I personally feel that a b/s ratio of 4/3, as in the Ford 302 or GM's short-lived 302, is the ideal

look at all the 2.5 L 4-cylinders running around...1/2 of a '302'

But we are still back to the original question: Why does my car seem so weak? I swear it seems way slower than my trucks with the 350.

because it's a 'small bore/ long stroke engine' 3.78 x 3.62, as opposed to the 350 which is a large bore / short stroke 4.00 x 3.48

SBLS engines run at lower RPM, produce more torque in the lower RPM range, and LBSS engines are higher-revving, with HP produced at higher PRM

You might want to fire your classroom, if in fact they told you that an LT1, LS1 or LS6 had a 4 inch bore and 4 inch stroke. :-)

They gave you the bore/stroke for the L31 (which is in my Yukon and Suburban though)

LS1 (my 1998 and 2001 C5 Coupes)

LS6 ( 2003 Z06)

LT1 (my 1988 C4 Vette Coupe)

WHAT ?

bore x bore x 0.7854 x # cylinders x stroke is what he posted

Gary,

I hope you do not mind my $.02 worth. You are completely right, as every Chevy book has always had this formula for figuring CID. I have no idea why there is an argument over rounding up or down, although as long as I remember the big three have always round up. I guess it would look weird to round down. I believe the 400 cid small block is one of the very few that is rounded down, but it is not like we are talking huge differences in cid.

While everyone is talking new compared to old, any idea why Chevy builds a 8.1 liter when they have had the 502 crate motor for a few years now? I was thinking maybe they were looking at wanting to make the engine as square as possible (i.e. bore and stroke close to each other). Just a thought. Have a good one.