[1963vert]

i read a post started by steve barack about this subject. the last post by ponchospidel on page 3. he talks about running a 389 crank and 389 roller cam in a 4 banger block.
has anybody else done this? would it really work?
could i please get all of you pontiac experts opinion on this?
thanks very much.

[63Banshee]

Yes, "it" really works.

[Bill Hanlon]

I don't understand. Given the V8's cam and crank, you'd have to stay with using the passenger's side of the V8's firing order. You'd end up with:

Cylinder 1 fires (this is cyl 2 on the V8)
crankshaft turns 180 degrees
Cylinder 4 fires (this is cyl 8 on the V8)
crankshaft turns 90 degrees
Cylinder 2 fires (this is cyl 4 on the V8)
crankshaft turns 180 degrees
Cylinder 3 fires (this is cyl 6 on the V8)
crankshaft turns 270 degrees
back to Cylinder 1 at the top

It seems to me like the variation of rotation between power strokes would not make for a smoother engine. Plus you'd need to have something (two rod caps bolted together??) to take up the space on the crankshaft where rods for V8 cylinders 1,3,5 & 7 are now missing. And that "something" would likely not match the balancing of the V8 crankshaft very well.

Of course my Pontiac has 8 cylinders as originally intended, so what do I know??

[63Banshee]

It's easier to wrap your head around once you get the rotating assembly in the block.

[1963vert]

63 banshee, is this a good way to go?
am i better off building the motor as pontiac created it?
just in the planning stages of building the 4 banger i have. i would like to squeeze some power out of this motor and i am just exploring the options available

[63Banshee]

If you're asking for my advice I'd say stay with a well balanced original rotating assembly, unless you are interested in experimentation. The original crank can handle gobs of power both n/a and boosted. They run well once you get the balance right.

[elefantrider]

As the saying goes, the juice is not worth the squeeze.

Plenty of people have made power with the stock flat crank.
They run pretty smooth when the tune and idle is set right.

How much power do you want and what is the rest of the car like.

[1963vert]

63banshee any advice I can get would be greatly appreciated.

Elephant rider I would like to get 400 horse out of the motor
N/a if that is possible. My tempest is a pretty clean v8 convertible car with a rebuilt
Motor and I am going to leave it that way. The 4 banger would be for my 61 belair.

[mechanickeith]

What trans are you going to use on the 4 cyl?? Have to make a starter mount for anything other than stock. Carb or FI? Lots of options out there.

[455Grandville]

Why is the Pontiac slant 4 so rough running ? The International 196 cid 4 cylinder (1/2 of a 392 V8) runs fairly smooth , so that wipes out the big 4 cylinders run rough theory -

[63Banshee]

400 hp... You're looking at low psi boost or racing fuel. Maybe e85 will get you there with moderate compression. Easiest and cheapest option is boost. Dream up some ideas and post them or send them direct. I'll help where I can.

Dave Johnson <dj@v-r-r.com>

[1963vert]

keith, i have a wc t 5 out of a mustang i would like to use for a tranny . the starter mount was something i did not even think about, good point!
i really would like this to be fuel injected but not sure of which stand alone system to use. again any suggestions would be really helpful.

grandville, thats funny you mention that motor. i have been working on a 63 scout for a customer and it does run much smoother than i thought it would.

63banshee, awesome thank you, i was thinking turbo in the back of my head.

[Jack Gifford]

I sure don't have the answers. But I've been trying to "soak up" four-banger knowledge for awhile now, as I'll be attempting a 4 HP/ci blown-fuel engine for my lakester. I've decided to go with what the designers of traditional inline-four race-only engines (Miller, Offenhauser, etc.) have used- flat cranks, center two throws together and 180 degress from end throws.

According to the reading I've done, inline fours have an inherent vibration that only a balance shaft can effectively overcome. I'm still researching whether a balance shaft will be a necessity in my 182 c.i. engine, to allow running it at up to 10,000 RPM.

[1963vert]

jack, how would you add a balance shaft to a pontiac 4?

[Jack Gifford]

I haven't yet worried about details of a balance shaft- sort of hoping it won't be necessary. But since I'll be fabricating almost the whole engine anyway, a balance shaft seems feasible (starting with my 'spare' M/T aluminum V8 block, closing off the unused bank, building a DOHC setup on the hemi head, etc.)

[voodoohalfbreed]

terry spidel has done this I believe, but I would like to know what you do and how it turns out. Please keep us posted!!!

[63Banshee]

Originally Posted by voodoohalfbreed

... I would like to know what you do and how it turns out. Please keep us posted!!!

Goal is to shakedown a new boosted "v8 slant 4" Tempest by next Spring. Engine is coming together (Thank you Terry!) and I hope to have the chassis done over winter. I could have engine dyno results by December. Merry Christmas to me!

[Jack Gifford]

Care to tell us about it?

[63Banshee]

Not a lot to talk about yet. Moldex stroker crank, clearanced cryo'd block, GRP rods, Precision turbo, custom roller cam, etc. I'll put a thread or 2 together when I get further along. 1 here for V8 internals and custom intake talk, 1 more build detailed in the race forum.

[voodoohalfbreed]

cant wait, I want to hear about the roller cam,and how it does!!!!
scott