hey guys im playing on doing an engine swap in a few months during next winter i was wonder what your opinions were on the 327 over the 350... im leaning more toward the 327 because ive heard that they can handle higher revs and are open to more mods... also is the swap any different for a 327 when compared to a 350 swap (both carbed)... thanx alot guys

 

The difference in stroke isn't the difference in rev capability. The quality of the valve train is.

The difference in stroke isn't the difference in high rev durability. How soundly the bottom end is built is.

If you don't have either engine, get the 350. If you have both, use the one that needs the least work. If they both need a thorough going through, build the 350 and build it with quality parts.

 

Ok, I've heard about the difference in rev capabilities between the 350 and 327 too much. Both engines are capable of the same rpm's, yet the 327 with its shorter stroke (albeit not a lot), equates to less reciprocating mass therefore will have the tendency to rev up quicker than a 350 (I am assuming identical builds). The difference is slight, but when you consider the speed at which the parts are moving, every bit counts. If you want the calculations, ask.

When building a street engine, you typically want to keep the rpm's down as increase in rpm's = increase in wear. High reving engines do not last as long as lower reving ones.

I am partial to the 327, mostly because it seems like everyone has a 350.

What you decide to build needs to be based on what type of usage you want out of the vehicle. You must decide that prior to deciding on which enge and how to build it.

 

More importantly, the shorter stroke equals less physical distance that the piston travels per stroke, thus each revolution takes less time to complete. You're right, the 327 should rev faster than a similarly built 350.

 

yea i really want a 327 just to spite everyone in my area with the dam 350.. dont get me wrong .. i love the 350... but i think having a 327 would just blow their minds... i want the car as a daily driver with around 300 at the wheels... this is the crate i was thinking about... http://www.golensengineservice.com/

look at the chevy carbed engines and you will see the short block and turn key... what do you guys think of this set up?

 

The link offers a 350 spring special...not quite sure what you mean.

You will have to do a lot of work to have a 327 keep up with a 350 due to the increased torque potential of an identically built 350. I ran a best of 9.89 with my S10 (327). I have now put the engine in my '85 Bird...can't wait to see what it will do!

 

go to the side of the screen and click the links... i couldnt give a direct link to the page.... u gotta click around on the site for it... and yea 327 will prob be my choice.... i just might use my summer money for an ls1

 

If you wanna talk short stroke rev motors, build a 302 and call me in the morning

*waits for RB, 5-7 and ede to throw fruit*

 

The reciprocating mass of the 327 is virtually identical to that of the 350. (The reciprocating forces are a little different, however.)

The shorter stroke means the piston doesn't have to travel as far, and therefore does not have to reach as high of a linear speed for a given crankshaft rotating speed as a longer stroke 350 piston - true.

However, as for what makes it rev quicker - that's a function of power being produced minus power consumed in order to produce the net power against a given resistance (weight of the car, for instance - there are also minor effects on valve timing because of the different piston speed and stroke-to-rod ratio). Since the 350 will pull in more fuel/air per revolution than a 327, and how much fuel/air you put in the cylinder is what determines how much power is produced, and how much power is produced vs. consumed determines net power, and since the difference between power produced in the 350 vs. the 327 is larger than the power consumed in the 350 vs. the 327, and the 350 will have more torque based on the longer lever arm against which the piston force is applied, meaning the engine will twist the resisting force harder than the 327 will, and torque is what makes the car move...

...a 350 will rev up faster than a 327.

(...all else being equal, that is...)

Of course, none of this changes anything that I said in my original response.

 

a 327 and a 350 are the same motor except for different crank, torque is what you want on the street, go with the 350

 

What???

How would they even know, or better yet, why would they care? If they had an otherwise absolutely identical 350, you'd lose.

In the simplest possible terms:

$$$ + 327 = HP
same $$$ + 350 = more HP

Pretty basic.

 

You are correct, except you left out a few variables that make a big difference.

1. to "rev" an engine is to freewheel it, as in in park or neutral...so weight of car has nothing to do with it.

2. piston speed is increased in the shorter stroke motors therefore compressing and igniting the fuel quicker. This is a simplistic generalization, but can be backed up through calculations.

People have the tendency to think of a 327 as a "rev" motor simply because the lack of torque over a comparable 350 means you need to run a steeper gear to get the same performance. The 327 needs to run higher rpm's to keep up with a comparable 350.

The 350 is a perfect all around street engine, great balance of torque to horsepower, I just get sick of everyone having a 350. Just my opinion.

 

Who cares about that? A smaller diameter torque converter will have more effect.

Piston speed is lower in a shorter stroke engine. The kinematics are altered slightly due to stroke-to-rod ratio, as I mentioned. 6" rod 350 will overwhelm that difference. The time it takes to compress the air/fuel is exactly the same at a given RPM for a 3.00", 3.25", 3.48", 3.75", or 4.00" stroke. The compression rate will be higher in the longer strokes, however.

Quote:

People have the tendency to think of a 327 as a "rev" motor simply because the lack of torque over a comparable 350 means you need to run a steeper gear to get the same performance. The 327 needs to run higher rpm's to keep up with a comparable 350.

The first 327 I drove was in a farm truck that weighed 10,000 pounds empty. It hardly "lacked torque". A 350 would have had more, of course. No matter what you do to a 327 to "keep up with" a 350, doing the same thing to a 350 will keep the 327 from keeping up with the 350.

There really is little you can do with a SBC and be "unique". Building a 302 borders on silly. 305's - we all know about them. If you find a 327, you can build a 350 for the same or even less money. 383's are neat, have their own "issues". 427 and 434 SBC's are becoming commonplace.

Closest thing to "unique" I've seen lately was in the small block Engine Masters Challenge that had a 360-ish CID limit (I forget the exact number off the top of my head) and averaged power between 2500 - 6500 RPMs. One guy built a .030"-over 307 block with a 3.75" stroke crank for 359 CID. Probably would have won the thing if he didn't have dyno-day problems. But, that combo required specialty pistons that you aren't going to get out of the Summit catalog. And, it was built the way it was specifically because of the CID limit and winning criteria.

 

 

a 327 and a 350 are the same motor except for different crank, torque is what you want on the street, go with the 350

 

ok you guys did help me out alot... thanx i appreciate the detailed answers.... but would a 327 have noticably better gas milage over the 350 when build with the sae parts? and when i do the swap can i still use the stock motor mounts and such? thanx (these factors wil determine my final descion)

 

The gas mileage difference between similarly built 327 and 350 would be basically nil.

As stated, they're basically the same engine, so it will mount in the car the same. You need to watch things like accessory holes on the end of the heads (choose them carefully), which side the dipstick is on, and rear main seal type (all 327's were 2-piece, some 350's are 1-piece).

 

Most 327s are also small journal engines... which means they use different cranks, rods, rod bolts, and bearings than a 350 would use.

 

yea i WISH i had my own garage to built my engine... but i dont even have a back yard to build a makeshift one... sooo im going to have to buy a crate.... what do u guys think of golens crate engines? how bout the zz4 from jegs?

 

Golen - Do a search on the Aftermaket Vendors forum.

ZZ4 - Great engine, great warranty. Available from your local dealer.

 

I just sent my 327 out to be built but i based the decision on the fact that it has been sitting in the engine stand for like a year....but i think the 327 will do the trick and will handle most of the imports in my town so i'm not too worried.....

 

i bet a 383/400 would of blew their minds .. theres no replacement for displacment

 

i got a 350 for $800 performer intake 600 cfm holley... comp cam... rebuilt heads.... 4 bolt main... forged crank.... and a set of black jack headers... (prob other stuff i forgot also) what do u guys think....