Hot Rod Forum banner

Motor Swap on a '53 pontiac chieftain?!?!

17K views 6 replies 7 participants last post by  flynbrian48  
#1 ·
I've recently purchased a '53 Cheiftain and it has a substaintial knock in the upper end of the straight 8 which is causing some of the valves not to open. The question I have is: What would it take to swap the straight 8 with a small block V-8? Also, any idea as to what would be causing the knock? First guess I'm thinking cam lobe problems as I am very familiar with V-8's, but the knock sounds more like a spun bearing. I've never encountered a straight 8 before...Any help would be greatly appreciated...Thank yah much!
 
#3 ·
Is it a tick or a deeper knock? If its a knock, it's not the cam or valve train....it's the main or rod bearings. You can find out approximately where the knock is with a mechanics stethoscope or even a broomstick against your ear.
 
#4 ·
http://www.egge.com/ those fellows have the parts if you decide to rebuild the engine that you have..Sounds like it needs to be torn down and done to me as there may be more than one issue..

If you decide to do a swap it will take some custom motor mounts and trans cross member as well as a driveshaft to get it all to work well..that can be very difficult or not so difficult depending on your fabrications skills..

Sam
 
#5 ·
There are many options for a car like this for a swap. Like mentioned before, if you want to keep it Poncho, a 400 or 455 would be good. If money is an issue, I'd be tempted to measure the rear track width and find a suitable donor being parted out (maybe a Tempest, or Firebird, or Nova) and swap in the entire driveline. Shouldn't be too tough to do....lots of room. Have fun.
 
#7 ·
I have a 4.8L LS1/4L60E in my '51 Pontiac "Tin Woody" wagon, and an LT1/4L60E in my '48 Pontiac convert. Prior to the LT1, the '48 had a 472 Caddy/Turbo400, and prior to that, a 230 Chev six and Powerglide. I can from experience tell you that anything you can think of will fit in your old Poncho's engine bay! Check out my photo album for pics of each, and what we do with 'em.

The small block Chev is an easy swap. Super simple to make engine mounts using the old fashioned flathead style rubber insulators from Speedway (or any other vender). The stock radiators will keep anything cool if they're in OK shape, and you don't even need to think about changing the rear end, unless you want posi. Use an overdrive trans like the 4L60 or a 200R4, and you'll get good economy, and it'll be quick too.

I did swap the rear end in the convert, used the donormobile Caddy Fleetwood (a '94). A full size rear fits perfectly, I'm running 235/75R 15 tires, with the original skirts. A F or A body would be too narrow. OK under a Chev, as they are about 3 inches narrower than the Pontiac body/frame. I've had both...

Have fun!

Brian