azmi951

I'm starting to build a new head since I have the dreaded ceramic damage on my current head. I'm very happy as I found new 48mm valves for $23 each. Not modified chevy valves. I also sourced springs for $72. I will do some minimal porting and blending as recommended by a guy who builds these heads for all the local racers.

Any recommendations on what to do other than the standard work?

rlm328

make sure the exhaust valve is capable of taking the exhaust temps. the 951 exhaust valves are sodium filled.

V2Rocket

where did you find these valves

azmi951

SI valves. they are in California.

Also I'm using the stock 951 exhaust valves.

DDP

Springs for $72? I don't know whether I should be impressed or scared for you....

Anymore info on those?

Techno Duck

Steam vent if you dont already have it done.

ramius665

Has anyone done an objective review of the before/after steam vent mod? I'm more than a little skeptical that it works.

azmi951

Yeah, the guy built all of Chris Cervelli's heads. I trust what he says. I also have one of his heads on my car now with those springs and over 140k miles. I think they have proved themselves.

azmi951

Good call on the steam vent. I will probably do this since I can see the logic behind it. It is also a simple mod and cheap insurance.

gt37vgt

well some call it standard stuff some don't ..
correct consistent seat widths 3 or more angle measure every stem height taper turn the guides don't back cut the exhaust valve CC the chambers after doing a little relieving around the valves .
Cafulley do spring install heights and check pressures at full lift as well
match port the inlet manifold and perhaps your Phenolic spacers
if the port job is big CC the ports also

Bri Bro

How does he remove the liners and what does he do to ports after the liners are removed? It appears that the liners are not required and they will kill a turbo if a big chunk breaks loose.

azmi951

Removing the liners involves buying an NA head. The ceramic i guess could be removed but it is easier to just get a core NA head and build it.

Bri Bro

Thanks Sean, I have never read that anyone removed the ceramic. I guess it requires more time and money then getting a n/a head.

azmi951

Also as a bonus the NA head has a larger volume exhaust port. My brain trust that I was going to have build it says that because of the larger port it requires minimal porting, more of just a clean up.

I'm thinking of sending the head to swain tech to have the chambers and exhaust ports coated to help keep heat out of the coolant.

Josh B

I haven't heard of anyone removing the ceramic liners - I don't think it is possible as I remember a graphic somewhere showing how the heads were cast with the ceramic ports already in the place and they are sizeable.