question about chevy v8

[andrewg3300]

I know this is chevy question but i really want to know since i plan on droppping it in my 73 z in about a month or so. Ok last year my dad and i put a 327 together. but we went back with a 350 crank. we used the old 327 rods. it worked out good and it runs great. my ? is whats the displacement. some people say it is a stroker or a destroker. but i think it is a 350 now. arent the rods the same lenght(327/350) . BTW the bore is the standard 4.0. I hope someone knows more than me but thats the easy part. thanks. OUT

[jmortensen]

The stroke and the bore make the displacement in all piston engines. So if you used a longer rod and a piston with a higher pin height to make up for it you didn't add or subtract displacement, but you did improve the rod/stroke ratio.

[andrewg3300]

thanks. All i changed in the engine, basiclly was the crankshaft. The pistons/wrist pins/rods were all left alone. they didnt have much play. Im guessing that a 350 crank has a longer through than a 327 crank. that would change the distance the rod traveles up the cylinder right?

[jmortensen]

The next question is why aren't your pistons hitting the head? Think about it, if the stroke is longer, then the piston goes up farther in the bore. If you used the same rod and piston that were in the 327, they'd pop right out of the bore and smack the head. I just checked and the 350 has a 3.48 stroke where the 327 has a 3.25 stroke. So those pistons would come out of the bore .23". Something else had to have been changed, or both engines must have been 350s.

[andrewg3300]

you make a very good piont. it is posible that they were both 350s. that is almost 1/4 inch(.23) w2hat about the distance from the center of the crank to the top of the bore. that would make a difference right? i dont know but you must be right. both 350s, it is the only logical idea.

[romeo_30906]

not neccessarily cause think of this to d stroke a 283 u have to put a 250 crank in it so that should shed light on the subject no it wont hit the stroke may be longer but the push hieght is compensated

[aldersonr]

The rods don't have anything to do with the displacement. It's only determined by the crank throw and the diameter of the piston bore. As for the length of the rods, they will change your compression ratios and rod angularity which affects torque output. Higher compression and longer rods will improve as the opposite will, of course, hurt. Sounds like you have a pretty decent engine in a very light car, have fun!

[lbhsbz]

The 350 and 327 both use a standard 4.000" bore. The 350 stroke is 3.48" while the 327 stroke is 3.25". The rods are both 5.7" The only small block with shorter rods is the 400, with a 5.565" rod (I beleive). Most (if not all) of the 327s used smaller main journals than the 350, so you can't just swap cranks. If you machine down the 350 crank, it will fit in the 327 block, and you will have a 350. The only dimensional difference between a 327 block and a 350 block is the main journal size.

If using the 350 crank, 350 pistons must be used. 327 pistons have a different compression height and would hit the head. If the 327 crank is used, 350 pistons will yield a horrible compression ratio.

[lonetreesteve]

How old is the engine? The 327 was discontinued by Chevy many, many years ago, so chances are it's a 350.

[biddljj]

Man.... Your are a real resource. Were you a engine rebuilder ?

Jay

The 350 and 327 both use a standard 4.000" bore. The 350 stroke is 3.48" while the 327 stroke is 3.25". The rods are both 5.7" The only small block with shorter rods is the 400, with a 5.565" rod (I beleive). Most (if not all) of the 327s used smaller main journals than the 350, so you can't just swap cranks. If you machine down the 350 crank, it will fit in the 327 block, and you will have a 350. The only dimensional difference between a 327 block and a 350 block is the main journal size.

If using the 350 crank, 350 pistons must be used. 327 pistons have a different compression height and would hit the head. If the 327 crank is used, 350 pistons will yield a horrible compression ratio.

[lbhsbz]

Man.... Your are a real resource. Were you a engine rebuilder ?

Jay

Not professionally, I just know my way around chevy engines....and VW watercooled (my last race car). I worked for Toyota and GM for several years and have a couple hundred engine jobs under my belt. The only ones that blow up are my own.... I have tons of books and references on SBCs, so if anyone has any questions, I'm sure I can come up with answers.

[czc_dude]

I'm more of a Ford guy, but recently found this, which indicates that there was more than one bore size for the 350 ... http://www.mortec.com/borstrok.htm