Hot Rods BORE NOTCHING

Thanks for all the the info, I will step back an take another look it what iam going to do.

 

Knowledge is of little use until experience has given it meaning......
The most memorable experiences are usually the mistakes we have made in life.
Best of Luck with your choice.

 

If I had the heads and they were the heads I was planning on running I would not give a second though to notching the bores for valve clearance. Lots of engines over the years have had the bores notched for various reasons ands they have worked out just fine.

There is an issue that needs to be considered though. The notch does not want to extend into the ring land area, Hell I have even had to over bore engine's that someone got to heavy handed with the ridge reamer for the same reason they got too deep.

 

A long time ago many +.060 283s were built with 1.940 intake valves and bores weren't notched. How about putting in new intake seats and cut them for 1.940 dia. valves? I would highly recommend screw in studs. If you have the +.030 domed pistons already, the only extra expense would be the head work and 4.56 rear end gears.

 

My question is: did all #461 heads come with the 2.020 intake valves and 1.600 exhaust valve diameters?????

 

No.

 

Ok... Because I remember having a pair in the late '70s that had the 1.94" and 1.50" valves with the 64cc chambers... I ended selling those for 100 bucks to someone....

 

That was actually my thought. I first thought the notching of the block would be to unshroud the valve, not to literally give it clearance because it's going to hit the block.

I would imagine that a valve that had to be cut in like that would flow like crap, essentially nullifying the entire point of running the larger valve in the first place. I also agree with what others have mentioned here, with small cubes from the 283, by the time you're taking advantage of the 2.02 valve, you're on the verge of floating the valvetrain as it is. I feel like you'd have better results with a smaller valve, with more intake velocity, an unshrouded valve, and probably better atomization. Not to mention the smaller valve will probably help to build a wider power band and give you some lower end power.