Bored&Stroked
Well-known member
Since you're going to build a 276 cubic inch engine, the Potvin 3/8 is a very good cam for it. 'Pete' is one of my good friends, you can't go wrong with a cam from him. As far as pistons go - lots of options and different price points. It kind of comes down to what you can afford to spend - for what reason.
I tend to run Ross forged pistons with 1.5mm, 1.5mm, 3.0mm metric rings - the best rings I can find. BUT - this is not the inexpensive way to go (ends up being about $100 a slug).
You can go with a cast piston and "traditional" ring packages for closer to $300 - $350 . . . so if you want to save a few dollars, then go this route.
-> Parts: Mac VanPelt is a great guy to speak with - talk to him about piston/ring packages. Like Gary below - he has a lot of what you may need.
-> Gary GosFast: He has some great valve, guides and spring packages - talk to him about a complete setup. He also has a lot of the other parts - so worth a discussion.
Rods - Consider New Ones: The stock rods are just fine, but if they need rebuilding, you might just want to buy a brand new set from SoCal for about $225 or so (non floaters - insert bearings). In the end, the cost will be about the same and you'll have new rods.
Balancing: Since you're changing up a bunch of stuff, I would have the reciprocating assembly precision balanced (including clutch, flywheel, etc). You'll love how smooth it will run.
Valve Job: This is the area where you want to ensure that your machine shop has the correct tools and knows flatheads well. I tend to see the biggest issues in this area - due to some shops not having the correct flathead mandrels for the seat work and not knowing the peculiarities of the flathead (like the valves are higher on the driver's side).
Piston to head Clearance: As Ole' Ron said - it is very important to "tune" the clearance to achieve a .040 to about .045 piston to head clearance. Running a tight 'squish' area is very advantageous to these engines. BUT, your machine shop will need to clay the heads, measure the head gasket thickness (about .052 - typically) and mill the heads for this to be correct. AND, he needs to check the valve to head clearances with the Potvin Cam. He may need to increase the depth of the valve pockets up at the TOP area of the valve reliefs in the heads. The valves are at an angle, so don't just let him fly cut the valve pockets parallel to the deck surface (like most guys do).
Good luck - feel free to PM me if you need anything. You'll have a really nice engine in the end!
B&S
I tend to run Ross forged pistons with 1.5mm, 1.5mm, 3.0mm metric rings - the best rings I can find. BUT - this is not the inexpensive way to go (ends up being about $100 a slug).
You can go with a cast piston and "traditional" ring packages for closer to $300 - $350 . . . so if you want to save a few dollars, then go this route.
-> Parts: Mac VanPelt is a great guy to speak with - talk to him about piston/ring packages. Like Gary below - he has a lot of what you may need.
-> Gary GosFast: He has some great valve, guides and spring packages - talk to him about a complete setup. He also has a lot of the other parts - so worth a discussion.
Rods - Consider New Ones: The stock rods are just fine, but if they need rebuilding, you might just want to buy a brand new set from SoCal for about $225 or so (non floaters - insert bearings). In the end, the cost will be about the same and you'll have new rods.
Balancing: Since you're changing up a bunch of stuff, I would have the reciprocating assembly precision balanced (including clutch, flywheel, etc). You'll love how smooth it will run.
Valve Job: This is the area where you want to ensure that your machine shop has the correct tools and knows flatheads well. I tend to see the biggest issues in this area - due to some shops not having the correct flathead mandrels for the seat work and not knowing the peculiarities of the flathead (like the valves are higher on the driver's side).
Piston to head Clearance: As Ole' Ron said - it is very important to "tune" the clearance to achieve a .040 to about .045 piston to head clearance. Running a tight 'squish' area is very advantageous to these engines. BUT, your machine shop will need to clay the heads, measure the head gasket thickness (about .052 - typically) and mill the heads for this to be correct. AND, he needs to check the valve to head clearances with the Potvin Cam. He may need to increase the depth of the valve pockets up at the TOP area of the valve reliefs in the heads. The valves are at an angle, so don't just let him fly cut the valve pockets parallel to the deck surface (like most guys do).
Good luck - feel free to PM me if you need anything. You'll have a really nice engine in the end!
B&S
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