Box Stock

Not another hemi thread but technical

W

WinstonSmith

New member
The canted valve configuration of the new head has me concerned about clearance.

I'd like to run this in a clone with the Z4M and a +020 long rod to close up as much or the head space as possible.

This will require some milling ( I would like to get down to around 17cc if possible ).
Welding if required if also an option.

Anyone care to share what the limits are for the newhead?

Lacking the new head or starting point I have to ask these questions.
 
I built an old style pred, put a hemi head on milled to 16cc (didn't measure what was cut, but I figure at least .080, cut to fin), black mamba cam, made great power..however the valves did touch (valve float) when ran on the dyno. I found this when I removed the head. I have pulled the vales and the contact wasn't enough to hurt anything. It just had 26lb springs, and I turned it 9000 on the dyno.
 
With 18# springs if you cut more than .060 off you are in danger of hitting the piston. That's a hemi head, flat top piston and a .009 head gasket.
 
youngengines said:
I built an old style pred, put a hemi head on milled to 16cc (didn't measure what was cut, but I figure at least .080, cut to fin), black mamba cam, made great power..however the valves did touch (valve float) when ran on the dyno. I found this when I removed the head. I have pulled the vales and the contact wasn't enough to hurt anything. It just had 26lb springs, and I turned it 9000 on the dyno.
Click to expand...
You Poboys south of the "Mason Dixon" really twist these 212 utility motors..lol. Mine is Milled .050", 28.5mm intake, NR274-0611, 26lb springs , will run all day long at 7500r's with no clearance issues. But I will agree that the 60363 really like rpms where as most clones fall flat after 7000r's.....
 
Renegade said:
With 18# springs if you cut more than .060 off you are in danger of hitting the piston. That's a hemi head, flat top piston and a .009 head gasket.
Click to expand...

I prefer the Fire ring .040" head gasket with SA builds. That gives me .030" more valve/piston clearance . The loss of compression is hardly noticed..
 
Thank you for the replies fellows.

The head is in play now and when it gets here I will have too see what it looks like and see if there will be a clearance issue.
Sneaks suggests I won't miss the compression loss.
But I would like to mill this to get as much as a I can and weld if needed ( and in budget, this engine could be a real budget killer ).

It was a snowy day in the north country and the clone on my old snowblower did its thing.
The fellow next me has a 305 briggs and marvels at the distance my old ugly snow blower, blows....
Even my snowblower sports a cast off 14cc head.

I find that I want to be around 10:1 to 11:1 on just about everything
 
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