SBC 327

Post any technical questions, FAQs or tutorials in this section
User avatar
CanAm17
Posts: 271
Joined: Fri 12 Sep 2008, 13:27
Location: Cape Town, South Africa

SBC 327

Post by CanAm17 » Fri 08 Sep 2017, 11:48

Have been looking at a new purchase which is currently running a Chex 327. Have done a fair amount of research, but there seems to be two schools of thought on this. Did Chev produce any 327's with 4 bolt mains or are they all 2 bolt? Reason I ask is nah we are looking at modding to full race spec - looking for around 450HP at 6800rpm, so 4 bolt, solid lifters, decent forged crank, forged rods, single pane intake, decent double pumper, around 11,5 compression etc a must. If it turns out that all 327'swere 2 bolt, we may just swop out for a 4 bolt 350 as a starting point and then possible go the 383 stroker route. I'm still a big fan of the best power for circuit racing coming in from 5000 - 7500 and will be trying to emulate what we were getting from our DZ 302 in the CanAm.
Input appreciated
1967 MGB GT V8
1973 Chev Firenza Can Am
1978 Ferrari 308 GTB
2010 Mini Cooper JCW

User avatar
Can-Am ZN
Posts: 735
Joined: Mon 23 Jun 2014, 15:27
Location: Valley of 1000 Hills, KwaZulu-Natal

Re: SBC 327

Post by Can-Am ZN » Fri 08 Sep 2017, 15:03

Hzt Anton,

Seems to be many conflicting views on this one.

Here is some debate on the Camaro forum that I was browsing the other day:

http://www.camaros.net/forums/18-engine ... -make.html

I know that you do get large journal 327 cranks, as this one that was up for sale:



Hope that you get a decisive answer from a reputable source.

Cheers
Gavin

1974 Chev Can-Am 302
1991 BMW 325iS Evolution (SOLD)


"The sad reality about the uneducated is that they don't know that they don't know." - Me

Image

User avatar
Waterhond
Posts: 1082
Joined: Sat 29 Oct 2011, 12:01
Location: Pretoria

Re: SBC 327

Post by Waterhond » Fri 08 Sep 2017, 17:14

Is the engine a small or large journal 327 ?

All small journal 327s were 2-bolt.

The later engines, just before the 350 was introduced, might have 4-bolt blocks.

Just my opinion, and certainly not reputable..

User avatar
jlebenon
Posts: 1331
Joined: Tue 31 Aug 2010, 11:48
Location: fourways,jhb

Re: SBC 327

Post by jlebenon » Sun 10 Sep 2017, 16:54

327 all 2-bolt ... But some did have forged steel cranks ...
2006 lumina ute
1973 El camino 353ci

User avatar
jlebenon
Posts: 1331
Joined: Tue 31 Aug 2010, 11:48
Location: fourways,jhb

Re: SBC 327

Post by jlebenon » Sun 10 Sep 2017, 17:12

And the dz302 was 2 bolt for 67' and 68' and still revved that high ...
2006 lumina ute
1973 El camino 353ci

User avatar
CanAm17
Posts: 271
Joined: Fri 12 Sep 2008, 13:27
Location: Cape Town, South Africa

Re: SBC 327

Post by CanAm17 » Mon 11 Sep 2017, 10:47

Thanks for the responses. For peace of mind, we're probably going to start with a 4 bolt, 4 inch bore and new forged crank. Just need to decide whether we go 3 inch stroke ( as per DZ 302 spec) or whether we go longer stroke for increased displacement. Still like the idea of the short stroke for high revs.
1967 MGB GT V8
1973 Chev Firenza Can Am
1978 Ferrari 308 GTB
2010 Mini Cooper JCW

User avatar
Can-Am ZN
Posts: 735
Joined: Mon 23 Jun 2014, 15:27
Location: Valley of 1000 Hills, KwaZulu-Natal

Re: SBC 327

Post by Can-Am ZN » Mon 11 Sep 2017, 19:05

CanAm17 wrote:
Mon 11 Sep 2017, 10:47
...Just need to decide whether we go 3 inch stroke ( as per DZ 302 spec) or whether we go longer stroke for increased displacement. Still like the idea of the short stroke for high revs.
Do it! :D
Gavin

1974 Chev Can-Am 302
1991 BMW 325iS Evolution (SOLD)


"The sad reality about the uneducated is that they don't know that they don't know." - Me

Image

User avatar
KSF
Posts: 306
Joined: Fri 07 Feb 2014, 15:07
Location: Western Cape

Re: SBC 327

Post by KSF » Tue 12 Sep 2017, 10:11

CanAm17, If you will also have to run that car on semi's (new rules), then a smaller revvier engine might work better as the big torque from big capacity could just over power the semi's completely. 302 already challenges full slicks, let alone a 327 or 350 on semi's. The back end will really have no manners! :)

User avatar
CanAm17
Posts: 271
Joined: Fri 12 Sep 2008, 13:27
Location: Cape Town, South Africa

Re: SBC 327

Post by CanAm17 » Tue 12 Sep 2017, 10:51

Thanks for the responses. For peace of mind, we're probably going to start with a 4 bolt, 4 inch bore and new forged crank. Just need to decide whether we go 3 inch stroke ( as per DZ 302 spec) or whether we go longer stroke for increased displacement. Still like the idea of the short stroke for high revs.

Yes KSF, aware of the new rules re semi's. I might even rub full treaded classic tyres - Dunlop L section or similar. As for a happy back end, it's pretty much what I'm used to and actually prefer. That short wheelbase is always going to be interesting and there's nothing worse than an understeering car. Get the front pointed towards the apex and keep the steering constant through use of the right foot :D
1967 MGB GT V8
1973 Chev Firenza Can Am
1978 Ferrari 308 GTB
2010 Mini Cooper JCW

dom
Posts: 136
Joined: Fri 17 Dec 2010, 09:55

Re: SBC 327

Post by dom » Tue 03 Oct 2017, 08:31

The longer stroke is not detrimental to higher revs. Piston speed of 20m per sec is a story from the past. I built a 377+ for a Mclaren M6 which went up to 10.500. That had a stroke between 3.5 and 3.75 inch and a 400 block. Can't remember all details. It was finding the right stroke and rod length to clear the cam lobes. After two seasons the engine was opened and still good for two more seasons.

Heads were from Heads by Rick in FL. That was in 1996.
Nothing is as it seems!

Post Reply

Social Media

     

Who is online

Users browsing this forum: No registered users and 3 guests