86budgetSC

Well one of my buddies is picking up a 70 chevy truck tommorow.It has a 327 with a 4 speed in it.Well he is building a 400 small block for it.So I offered to buy the motor from him.To either put in my truck or my camaro.

First off one of my other buddies has a built 327 in his 72 chevy truck and well it runs hard.

I was thinking first of all do a rebuild with some nice forged pistons.After that I am not sure what I want to do.I plan on buying some pro-topline heads with my tax money and either putting them on this motor or the 350 I am building.So I will have either vortecs to choose from or pro-toplines.


What is the potential of a 327 compared to a 350.Also if it is the large journal.If you put a 350 crank in it.Won't that just make it a 350?Also I was thinking about maybe some 6 inch rods and really making it rev quick.


any idea's?

ME Leigh

A 327 has the same horsepower potential as a 350 but will make less torque. It will also make HP higher in the rev band. It will work well if you have 3.73 or bigger gears. If its an actual 70 327 it may have a large journal crank so a 350 crank will drop in, or a 383 crank will work.

dans82bird

if its a large journal you are right... a 350 crank will drop right in.

86budgetSC

Well right now I am thinking.

Bore the block .030.All new freeze plugs,cam bearings,etc etc.

Use the stock crank.With 6.0 inch rods.(if I can find the proper pistons)

a Big solid roller cam,Forged 11.5:1 compression pistons,Vortec heads,Air gap intake 750 holley,And an msd igntion lighting it off.Should be able to put my 86 in the 12's with 4:10 gears and some traction.11's on the bottle.

ME Leigh

I think that will be a cool different setup. Sounds like fun!!!

86budgetSC

I was just thinkin while I have you attention.I have a 307 out of my 69 camaro.

I thinki it would be cool to make it quick.


I was thinkin if i use a 350 crank.Which has a 3.480 inch stroke.6.0 inch rods and pistons for a 283.(same bore as a 307)Then the difference would be .3 inchs.Because the stock 307 crank has a 3.25 inch stroke. And the 283 has a 3.00 inch stroke.

Is there anyway I could make this work.Without special pistons?I just think it would be cool to have something different.

five7kid

iTrader: (14)

You would have to use shorter rods, not longer.

So, you'd either have to have really, really short rods, or special pistons.

If bored .030" over, you'd have a 333 cid with a 350 crank.

In the Popular Hot Rod "Engine Masters Challenge", with a 366 cid (I think) limit, one guy did a 307 block with 3.75" crank (359 cid). It made pretty good power, but he had some other problems that kept him out of the top. Interesting idea, though.

Yes, he had very, very special pistons for it. Engine would cost over $10k to build. I think I'll stick to "normal" SBC's...

ME Leigh

five7kid is right, you will need shorter rods not longer. Or pistons with a shorter compression height, not longer. You could use the 307 pistons a 350 3.48" stroke and 400 5.565" rods. To build a short rod 307 stroker. But why, really?

Its not really worth building a 307, they have a pretty small bore, which limits airflow.

I would take out the 3.25" large journal crank and sell it to somebody that wants to build a 327 or short stroke 400 = 348cid.

zippy

i'd have to look it up, but i don't believe the 327 was available in a truck in 70. either way, build it for rpm as that's all it's good for with such a short stroke. build a 327 with 6 inch rods and around 11:1 compression, it may be worth it then. try to keep it to be able to turn 6500 at least.

86budgetSC

Well to be honest I am not sure of the year.I do know the truck has a 70 clip on it though.The guy says it is a 327.

Hey zippy I read you have a 92 sonoma that runs 15's.I had a 91 sonoma st.It was 4wd with a 4.3 in it.The motor was rebuilt.With and edelbrock cam and matching chip.Edelbrock tes headers.Also edelbrock intake and a tbi off a 350.It ran pretty dang good.It would break the tires loose at 45mph.


Unfortuantly I wreck it in july of last year.I might be getting an 88 s10 to put that 4.3 in.This time it is a 5 speed though.Which should be even quicker.

onebadwagon

dont ditch the stock crank, use it, keep it a 327. everybody is always quick to go with a stroker, leave it alone and make a little more RPM, get some good 210cc heads a good custom cam, and spin the **** out of it.


adam

ME Leigh

No don't get any heads larger then 200cc, even that is really pushing it.

onebadwagon

if he is talking about some cam & compression a 200 cc head would probably be a better bet, but if nastiness is the goal, the bigger head has more potential.


adam

Marshall89ws6

also those large intake runners decrease low-end torque... and on a 327 which already lacks torque compared to a 350... i wouldnt go over 195ccs.. 200 is pushing it. you need some of that torque to get you moving.

Marshall89ws6

haha i posted bassically the same thing... but i didnt see yours b4 i did mine.... my bad.

86budgetSC

Well like I said they will probably be the vortecs I have.Which are 906 castings.

Whenever I put them on they will have new manley race valves all new seals,guides,screw in studs,guideplates,Etc etc.

If I can find pistons for the 6.0 inch rod I will do that.

onebadwagon

havent you ever heard of gears and stall. seriously guys, if you look at who is going fast with short stroke motors, they dont do it with LOW END. the motor is built to rev, let it.

adam

ME Leigh

I agree 327 like to rev, but you will not gain any power at all going with a head that big. But you willl lose lots of torque.

Torque makes you go, horsepower is for show!

dans82bird

afr 210's, victor jr. and a huge *** turbo!!

iroc22

There's no such thing as a '70 327. 1969 was the last year of the 327 and it was left as a 5k redline, 2bbl carb, base engine (with 210 gross hp).

I'm wondering why the general concensus here is that the 327 will automatically rev higher than a 350. Really it's more dependent on the heads, cam and intake rather than the bore/stroke combination. Throw the same top end on a 327 and 350 and the only difference you will see is the 350 will make slightly more torque and they will have very similar redlines.

zippy

tha's what i thought, i was pretty sure without looking it up that the 70 was 350's, 307's, and 400's. it's also correct, the 327 i s just easier to get more rpm out of since the smaller cubic inch rev's higher with the same cam. unfortunatly, a 383 will outrun a 327 similarly built anyday. short stroke engines or only good for small cars to keep traction not such an issue.


on my sonoma, that's pretty much stock. i may do a few things to it before i get rid of it, but it's on it's way out. my 03' silverado is in and ready to be bought so i can race that. should be much faster. i've also built a few 4.3's as you listed, they go ok for a tbi engine.

86budgetSC

Well then it looks like I will have to get the casting #'s off the motor.


So do you guys think it is worth it.My buddy still hasn;t got the truck.the guys with it is always "busy"

I was going to buy the whole engine off him for 300 bucks.I know it has an OLD edelbrock intake on it.Other than that I believe it is stock.

I am going to be building the motor for my 86 sport coupe.Everyone has 350's and 383's.I just wanted something a little different.

ME Leigh

Yeah, i didn't think there were 327 in 1970, thats why i wrote if its an actual 1970 327.

onebadwagon

i believe it was already stated but the reason that everyone thinks a short stroke motor will spin higher than a longer stroke motor, is because it will. given the same pieces, the shorter stroke motor will rev higher because the rod/stroke ratio is better, and the smaller cubic inch the motor, the more effect cam/heads have towards it.
that probably isnt coming out how i meant, but basically, 400 with the same cam wont rev as high as a 302.

adam

ede

i love this 327 revs higher line of thinking. like a 1/4" less stroke will magically allow the engine to go another 1000 rpms. the ability of and engine to move air is what in reality allows an engine to reach a given rpm. you might be able to do some math and find a better rod ratio or weight savings or something to prove your point, but real word applications a xxx cubic inch engine doesn't spin any faster than a yyy cubic inch engine based solely on stroke length. if stroke was the sole factor in how fast an engine could spin a 289 would spin higher than most all SBCs but it doesn't. my mercades would rev higher than most SBCs, but it doesn't.

RB83L69

I always love it when this line of logic comes up.... all that monkey-spank about higher RPMs surely means that back in 1970 when 350s came out in Z28s, they surely would have lost races to all those bad-to-the-bone high-revving 302s and 327s out there. But somehow or other I don't recall that happening. In fact, I also seem to recall that a 69 302 with a set of 041 heads, a 346 cam, the "Z28" intake, and a Holley 3310 would produce 290 HP according to the factory; but a 350 in 70½ with the same heads, the same cam, the same intake, and the same carb produced 370 HP. Now we all know those numbers aren't accurate or anything, and that the 302 in particular was under-rated; let's give it the benefit of the doubt, and guess that in factory trim it actually produced 325 HP using the measurement system of the day, probably closer to the truth. Notice that the HP numbers are almost exactly 350 / 302 different. The numbers for the 327 are right in between those for the 302 and the 350, as they should be.

An extra 150 RPM or whatever that the shorter stroke will move the curve upwards, doesn't make up for the lesser amount of fuel that is burned. That's why people with 350s that want to go faster turn them into 383s, not 327s; and why you don't see 327s winning heads-up races against 350s.

To answer the original question, the potential of a 327 compared to a 350, is essentialy 327/350, or 93.4%, as much power. You're losing by 6.6% compared to an otherwise identical 350. Nobody is going to notice the casting number of your crankshaft, or the wrist pin height of your pistons, when you going across the finish line in second place. "Different" means "loser" in this case. Not that a 327 is a bad motor or anything like that; the 350 is just that much better, that's all.

rx7speed

it goes a lot further then that


with the shorter stroke you have a better rod stroke ratio that would produce less side loading of the block and crank, better rod/crank angles, less inertal forces on the crank/rods, much slower piston speeds putted less stress on the crank/rods/wrist pins.


even though low end torque might not be as high as a longer stroke motor a shorter stroke motor like a 302/327 generaly has a wider power band.

another thing I want to mention is something with build up of the motor. the motor itself doesn't just make up how fast it runs the 1/4 mile there are many/ many other factors, and even though you might have a motor lie a 383 that revs up to maybe 4500rpms then runs out of steam vs a 327 that revs to maybe 6500-7000 rpms yes the 327 will be put at a dissadvantage by pure hp/tq PEAK numbers alone but with the use of gears it has the chance to overcome that disadvantage that the motor has... now maybe not always but there is that chance.


there is more I want to type just outta time

PhilM

well I dare to be different and am finishing my 302 right now for my 91 Camaro. NOT an original Z motor, just a 327 block (std bore) that had a steel 283 crank stuffed in it. 12.5:1 compression with ported bowtie heads and a .525 cam. I think the fact that there are hardly any 302's out there makes this unique, and Comp Cams says this thing should pull to 8,000+ easily. machinist doesn't recommend it with the rods I have, but I do plan on revving the snot out of it. In a few weeks it will be running and I will let you know. By the way, with the flow numbers on these heads, this thing should run in the high 11's in good conditions....