Straight 8 engine rebuild questions

Hello Straight 8 guys!

I'm rebuilding the straight 8 out of my 53 Special 45R.

It had been sitting for 41 years before I just recently got it.

I tore it down to find that # 4 and #5 pistons had holes burned in them. Also in the trunk of my car there were 2 burned pistons. The 2 burned pistons in my engine were replacement pistons. Are these engine prone to burning pistons? Does anyone have any insight on why it would have burned these pistons?

The block is standard and will probably be bored .030 within a couple of weeks. I am going to get the pistons from Egge's once i know what the bore will be. I want to bump the compression up some for some more power since I live in the mountains by Big Bear CA. How much is safe to mill off the head? I saw that on the "How to Hot Rod an I8" on this site said you can mill the head up to .175. I want to be able to run pump gas and not have overheating and starting problems. I still plan to run the stock intake and exhaust manifolds with the 2 barrel Stromberg Carb at this time. That is unless in the future I can find a dual carb intake which would be cool. My stock cam and hydraulic lifters are in great shape so I am going to be reusing them with this rebuild. I am having my head done at this time as well


Any guidance on how much to mill the head on my 263 would be great.

- Jeff -

Before you start taking material off the head and block you should know how much has been removed previously.

The holes in the pistons is usually caused by too hot spark plugs, and too lean a mixture. The lean mixture could be carburetion, leaking intake manifold, or poor seal around carb allowing a lean mixture.

With that being said, does anyone know a cc range for the straight 8 heads? That or what kind of cc range should I be looking to get?

- Jeff -

Do yourself a big favor and have your cam reground. The straight 8 needs to breath to make more power. There was a shop in Florida that did a cam for me several years ago. Valve lift was increased from the stock .375 to over .450 and duratution was increased slightly. I was fortunate enough to start out with a NORS cam, but they can do your used stock cam as well. If you go the cam regrind route also use new lifters or have yours reground.
Concerning the head, I had mine milled .125 inch and the block decked .125 inch. This was safe for both. My block was bored .030 and also line bored.
Buick had a dual carb, dual exhaust set up in the early '40s which is ideal for a modded engine. Again, these engines need to breathe to make good power. I was fortunate enough to find an engine builder/machine shop in Ohio who used to race the straight 8 back in the day.