clarke5700

i have come accross a cvh lean burn head its had a light port/polish and 4 new valves

ive been reading up on the heads and found that they dont flow as well as a standard xr2 head.

but because its a lean burn head with the heart shaped dishs does this mean it will be higher comp?

im gonna be doing a head gasket on my fez soon and was wondering wether to fit this head wile im at it?

what do you cvh people think lol

FASTdan

I've never heard of the lean burn being any worse flowing than the normal hemi - but thats irrelevant if its been worked anyway as it should be better regardless (assuming it wasn't a complete moron who did it).

However, it wont fit your standard hemi CVH i dont think as the pistons protrude slightly iirc and would contact the non-hollowed bit of the chamber on the head. And even if it did it would send the CR through the roof.

Fast Guy

Was it not HT racing back in the late 80s or whenever that used to prefer these heads for making more power?

clarke5700

humm gonna have to have a look

clarke5700

bttt

Karlos G

iTrader: (4)

The lean burn head suffers from some valve shrouding by the chamber walls and so flow is not so high as the early head design. The differences are not major though and a tuned road engine will produce perhaps 5 bhp less than a similar hemi engine. The lean burn head requires lots of metal removal in the chamber as well as the ports to obtain good flow and so takes a lot longer to modify than the hemi head. Given that all this extra work costs more money and ends up producing less power too, I generally convert late engines to hemi design if cylinder heads are available and if high power is critical. Copyright David Baker and Puma Race Engines