I've got some small block stuff gathering dust and want to run some parts by everyone to see if I should put it together. .040 11:5:1 domed cast pistons Steel Crank stock rods sbc head casting # 3973487X 2.02's 75cc chamber 268 comp cam offenhauser/ rochester 3x2. Looks like it would all work well together , but am not sure. Big pistons, but also big combustion chamber, so I wouldn't think the compression would be very high, 10:1 maybe? 268 only good to 9:1? thanks, charlie
I woulds hang out for better heads if it was me.........but it all depends on what fuel you are willing to run and what kind of performace you are looking for...Goodluck, littleman.....I personally do not use cast pistons in what I do, but I Drag race my stuff..and if you do put it together....have it balanced....
I'd probably trade the pop up pistons for some flat tops. Maybe you don't need .040" over anyway. With flat tops you can probably run fine on pump gas, but you might have troubles with the pop ups.
With "pop-ups", cast heads, and "smallish" cam it will very sensitive to fuel quality and ignition timing. If you do decide to try it, retard the cam timing 4 degrees (on the intake centerline). This will help to bleed a little cylinder pressure to make life easier on you.
The 487X heads are very good flowing heads. I ran a set on my IMCA modified for a couple of seasons. The 882's, 993's and 441's are also good flowing heads. The 882's have a tendency to be cracked when found but it's easy enough to find a repalcement.
ast pistons are fine for a street engine. The cast pistons are mosly solid dome and can be milled off in a lathe. I'd leave the domes and find a bigger cam, like a 280. If you can find spec's on the pistons, find out what the dome volume is. You can make a better decision that way. I've balanced a lot of engines and one thing I can tell for sure is they're sluggs. Most were heavyer than a stock piston. With exception of the old Hi-duty pistons, but as far as I know there out of buisiness.
^^^ I agree with what he said about that 268 cam and 11:1 pistons... You'll need a cam at least 280, maybe 290 to bleed off cyl. pressure; That is unless you're running higher octane fuel than pump gas.
The Jalopy Journal
