Stealth heads clearance issues

[eagleone1983]

Ok I haven't actually seen it yet but my builder called me yesterday and told me he is having a clearance issue with the stealth heads on my 383. What he explained to me or what it sounded like to me was the exhaust valve is hitting the cylinder edge at the top. Has anybody heard of this clearance issue before because I haven't. He said some fixes would be to use smaller exhaust valves (not gonna happen, the exhaust valves on it are the stock ones the stealth heads come with), bore the engine out more (which also is not gonna happen, its already bored out .030 and I'm not buying all new stuff), or he can machine notches on the edge of the top of the cylinders for the clearance. Anyway not that I'm doubting my builder I just wanted to see if anybody has heard of this. I'll also be calling 440source.

 

[eagleone1983]

Well I answered my own question and figured I'd post my answer in case anybody else has the same problem. I called 440source and he said that the clearance issue is normal with a 383 with standard boring (4.25") however mine isn't it is .030 over but I still have the exhaust valve hitting. I talked to my builder and he showed me the problem. Then he showed me a Chevy block to give me an idea of what he'll be doing (I guess this is a standard thing to make clearance on a Chevy block). So he is just going to take a die grinder to the block so the exhaust clears. He said on a street motor such as mine I won't notice any difference and only a tiny bit of cc's will be added to the combustion chamber.

 

[69 Runner]

2.14 & 1.81's?

 

[eagleone1983]

Yep

 

[dantrap]

Your builder will notch the cylinder wall a bit, should be of no concern.

 

[Meep-Meep]

Factory Max Wedge blocks are notched to clear 1.88" EX valves so no problem.

 

[scotts74birds]

I wonder how many people DIDNT catch that clearance issue ahead of time.

 

[Meep-Meep]

I wonder how many people DIDNT catch that clearance issue ahead of time.

Probably no issue with .256" at the valve :rolling:

 

[eagleone1983]

I wonder how many people DIDNT catch that clearance issue ahead of time.

I'm not sure which is why I figured I'd post it up here so us with lesser engines know about the possibility of some extra machine work.

 

[moparstuart]

I'm not sure which is why I figured I'd post it up here so us with lesser engines know about the possibility of some extra machine work.

yeah i would be pissed if i was just trying to do a bolt on upgrade in the car. Then guess what now you need machine work .

 

[daredevil]

273s are notched for 2.02s. if i,m not mistaken they all have to be notched to unshroud the valve when using 360 heads