206 replies to this topic

[Redslur]

Hi all

Have wanted to do this for a while now. I know there has been a few 308 build threads of late, and I have truly loved reading all the info in these threads, but as I am an avid fan of the "ol 308" I just wanted to share others peoples experiences with building 308's and the horse power figure you have achieved.

I am not interested in stroker combos at all as I am purely keen to see what people do to their 308's and what sort of power they achieve.

My first combo was a totally stock bottom end, standard compression, standard bore 308 which I fitted a Crane 286 hydrualic cam, new lifters, very well ported Red heads with Yella Tearra shaft mounted rollers, Edelbrock Performer manifold, 670 holley and Roll Master timing gear set. The exhaust was a set of 1 5/8 extractors, into a dual 2 1/2 inch engine pipes and through into a single 3" system. From this combo I achieved 238 RWHP. The car flew for such a simple combo.

As a result of a rear main oil leak, made worse from the drive to and from Toranafest last year, I decided I would pull out the engine and fix the dreaded leak. As you do in this situation, you check everything out and decided to refreshen the whole lot up. This brought about my next combo.

I maintained the red flowed heads and rollers as they were really well done, changed cam to a Crane 304 hydraulic, bored and honed the engine and fitted a set of 30" Flat top pistons with new rings. As well all new King bearings, A9L rods, ARP rod bolts, ARP studded Main kit and balanced the whole bottom end assembly. I also kept the Edelbrock Performer maniflod and 670 Holley. From this combo I got 265RWHP. I was pleasantly surprised given the engine has only traveleld 400kms since I have built it so there should be a little more in her when it is properly run in and has loosend up. Needless to ay the car goes heaps better!

So let me know your combos so we can share the info for future references. I don't mine if you have fitted alloy heads etc, just not interested in stroker combos as it doesn't typify the true results for a 308 CI motor,

Cheers, Gerry

[Redslur]

Very similar sounding combo to mine so you should get around about the figures you anticipate. Mine was a 198 RWKW from memory.

Also hoping to hear from some on the old skool boys who have built many 308 combos over the years....

Thanks for puttimg yours up lxssv8.

[ACJ]

Hi Gerry

I think you can get a lot of information out of the stroker combos.

The power you get out of any engine come from the heads (as long as all other part support).

The problem is the revs. The smaller the cubes the more revs. So your 396 making 500HP @ 6500 would = roughly 355 500HP @ over 7000 and 308 500HP @ 8000 or over.

So the part needed to pull 8000 revs would brake most budgets.

But still if you see a stroker you like, take not and with more rev you can be in the ball park. More important there part list will give you a good idea on what you will need.



Nice work, you have a good combo and a lot of fun to come.

[Redslur]

Good point Adam. I am certaninly not apposed to strokers, just wanted to see what sort of combos others have and what sort of power they have gained from the trusty old 308's. I am keen to see cam and head combos i.e VN heads with a solid cam etc. I have built several 308's over the years but only ever done smaller stage 3 type motors with around 200RWHP mainly as they were daily dtivers at the time. The last two combos have been fun and retuned my mechanic skills a little as I have been off the tools for over 12 years now....

Thanks for your input though!

Gerry

[76lxhatch]

Interesting thread, I'm reasonably happy with mine:

Standard 308 crank, spike rods and 30 thou over flat top pistons
Yella Terra/L34 style big valve HQ heads, around 10.2:1 compression
Edelbrock Performer manifold, modified Quadrajet on 1" spacer
Accel billet dizzy and MSD 6A/blaster ignition
Pacemaker 1 5/8" tri-ys with twin 2 1/4" exhaust
Cam is a baby solid 228 deg @50 thou, around 450 thou lift
High volume sump, Romac steel balancer, Yella Terra roller rockers

There is no dyno here so I don't have much idea what the power output is. I've run it down the drag strip a few times but no traction - started at mid 14s before a lot of changes and hasn't got any faster, just spins the wheels more (not only difficult to get off the line but spins them quite badly into third gear now)! Got a pair of Hoosier Quick Time Pros to have a play around with when the season starts again later this year, should be interesting.

It does what I want it to do at this stage, next step would probably be a stroker with similar configuration and probably a bit bigger cam.

[Redslur]

Wow that is a good power gain. I have heard that the spacer can work. I wanted mine all under the bonnet so won't be trying a spacer. 200RWKW is pretty quick anyway in a torry :-)

Good combos lads, keep them coming fellars.

[jason365]

spacers can work if the combo needs it, ive seen as much as 20rwkw from just adding a 1'' open spacer.

[76lxhatch]

My spacer is mainly there because the throttle linkage gets stuck (wide open!) on the manifold without it...

[Redslur]

Common lads. I am sure there are plenty of good combos out there that people have built. This is a not a pissing into the wind comp, just a good thread so that people can see what has worked for others to base their project off. Struggler??? Old Johhno?

[mr5000]

i havent had my car dynoed yet but the lil 308 slap job goes alright
red 308 standard bore flat top high comp pistons crow 5603 cam i think
red pre pollution heads and manifold all matchported at home slightly tweaked quaddy shitbag extractors with twin 2 1/4 system bosch hei dizzy with summit 6al style ignition

with the old banjo and the 13s it ran a best of 14.7 @98mph with heaps of wheel spin having open centre and 205s
plannign to get back to the track as soon as i get some big wheels now its got a 9 inch 3.5gears truetrac

[Redslur]

Good to hear. A 14 second pass is nothing to sneeze at! I haven't run mine down the quarter but will in the near future. Not sure on what sort of time I would achieve...

[mr5000]

i was pretty happy considering the whole build including parts machining and buying the block topped in at 1200 have had the dizzy graphed and added the 6al since and had carby tweaked more feels like it has alot more power so looking forward to its next outing aiming for a mid 13

[ozyozyozy]

i can get in on a bit of this action.
been using 308`s for years.
current engine is 308
vt heads, 2.02 valves
platinum roller rockers
big valve springs
solid roller cam, 560 thou lift, cant remember rest of the specs.
bronzed lifter guides
4 bolt mains
standard crank, prepped
scat h-beam rods, standard holden length
srp forged pistons 10.5 to 1 comp
inner active single plane manifold
barry grant 650 double pumper, made a cold air tray to sit on top of carby
trend pushrods.
acl race bearings
uuummm cant remember much else at moment

346rwhp, i spin it to 7000rpm.
id like to go back to a standard vn rod with bushed little end or go to a 6 inch manley conrod, something lighter than the scat rods(there a fairly heavy aftermarket rod).
and future goal want 7500rpm, love the sound.

[AbsynthHatch]

Oldjohnno do have a links to that build thread on those forums you mentioned please mate

[TerrA LX]

Actually the topic states no strokers please.

[TerrA LX]

Spammer.