pontiac straight 8

I've got a 1939 Pontiac straight 8. I'd like to build it up slightly to get some more power out of it. Any ideas, or bolt-ons that are still available?

 

I would:

1) mill the head for more compression
2) build a header (or split the stock manifold)
3) build a multi-carb log manifold, and
4) see if someone can regrind the cam

-Dave

 

I have a mallory dual point for a poncho straight eight for sale:
http://www.jalopyjournal.com/forum/showthread.php?t=129203

 

I dont think much at all was made bolt-on wise. But I saw this on egay a while ago, went for big dollars...

 

Check with these guys about regrinding the cam
http://www.deltacam.com/

 

cool guys, thanks. what do i need to do to make the new exhaust/ intake? just try to fabricate a flange for the block and weld it onto tube or something for the carbs?

 

Sounds like you've got a good handle on the concept. I'm certain if you spend some time getting comfortable with the search feature, you can find an illustrated tech article to show you how log manifolds and exhaust headers are built.

Personally, I like to use Google's "Advanced Search." I just limit it to jalopyjournal.com and search for whatever terms I want.

-Dave

 

I tried to find some hop up parts for my st 8 and I quickly found out that they are few and far between. If you are good at fabing, then you should be ok to do your own stuff. Good luck to you

 

That is surely one of the reasons for building a vintage engine. When somebody says "Where did you get that?" you point to the workshop. Makes you feel good.

 

If I had one it would have a 421 or 428 in in with much quickness. The straight eights are smooth, good torque, but not good for power. From Wikipedia :

As with all "straight 8" engines, the "Silver Streak 8" was beset with crankshaft harmonic vibration problems that would cause crankshaft breakage or excessive main journal wear. Adding to the problem was the propensity for the block to "sag" over time, making crankshaft journals off center, exacerbating the already weak crankshaft's propensity to break at the main journals. An accessory sold by Pontiac dealers in the late '40s and into the '50s was a bolt on brace, the purpose of which was to try to reinforce the overly long block. Rare was the "Silver Streak 8" that made it to 80,000 miles or so without either a crankshaft failure or a rebuilding.

 

thanks alot guys, big help, will do my research and possibly try to build one

 

Cool. I hope you'll do***ent it here. I'm planning to hot rod another unusual motor - Continental flathead industrial motor - at some point in the future.

-Dave

 

I'll try if i ever find out what the hell I'm doing hah