2 replies to this topic

[Hpal]

Hi all, 

I plan on cutting some valve seats myself using HSS cutters I'll be buying in the right sizes for the 202 head I'm reconditioning (no hardened inserts). Apparently they can make the pilot spindle which goes in the reamed valve guide any size I want. Advice from this forum has suggested that a size of 7.1mm would be too loose to make a good seat. The valve guide size of 9/32" equates to 7.143mm (0.28125"). Should I get it 7.14mm (0.2811") ? This is a very close fit and would hold it true, I could linish it down slightly if it was way too tight. Any thoughts before I make the purchase? 

*Yes I know I could get the seats cut professionally but where is the fun in that?

[Spider]

I'd have to measure my Pilot to get an exact size, but it is a nominal 9/32". Going size for size is asking for the Pilot to jam up, you'd want to go 1 or 2 tenths under.

[Project_1275_GT]

I recut my valve seats in my head by hand. New valve guides were fitted first. The head had hardened seats in when I got it. I checked the valve alignment and it was poor. This makes me think whoever fitted the hardened seats did so with poor tooling and worn valve guides. With new guides fitted and reamed I used a hand tee bar with 9/32 guide with cutter. This was a slow process to get all seats at the correct depth and recenter. I used 2 different angle cutters to slightly improve flow. It’s possible by hand. But doesn’t cost much to have new seats fitted and cut. Probably cheaper than buying the reamer and cutters.