I now have three Cossy heads with following specs

A - 2WD YNO627 - V86HF 6090CA Coscast 138.8 mm no corrosion
B - 4X4 YNO643 Coscast V86HF 6090AA 138.6 mm no corrosion
C - Crate RS500 YN0627 V86HF 6090CA 138.3 mm no corrosion, needs line boring on cam tunnel.

Assuming all heads need valve guides replacing and that they pass pressure testing and hardness testing.

I want to get one head ported and put on my near 500hp engine build. Will have solid lifters, double valve springs, Mike Rainbird cam in it.
Keep one as a good spare maybe put on second block I have.
Third is the one I might sell. (yeah Im a hoarder )
I am going to get all heads reconditioned while they are being measured.

What would you do ?

Here are some pics of heads

Left to right, A 2WD, B 4X4, C RS500

 

4wd one offers better HG support, that's the one I'd go for all else being equal.
tabetha

 

The rs500 is little more than the 2wd, flog that to one of us lot as you will get a good return despite the cam tunnel needing doing.

 

I think you might be right Andy, I am going to get the cam tunnel done and have it fully checked out. I cannot sell somethng that is not 100%

 

4wd Gav - you will need to make a turbo support anyway for the gt35.

Near 500HP build You'll spank that.

Have you decided who is doing the porting yet? Spoken to Aaron or Danny?

 

Good point on the 4WD head Tabetha, I think that 4WD heads have a little more volume in them to allow for. I will get the burette out and see if I can measure any difference.

 

Not yet Linc, I do know I need to get good flow to minimize surge of GT35. I might spend some time on the EECIV as well in that regard.
I am not claiming 500HP until the dyno tells me so, I have seen a bunch of people have to push hard to get it.
Good point on Aaaron and Danny, can you send me thier contact details and I will get onto it. I am gonna take the heads down to get them checked out first.

 

Thanks for the guidance team

Im going for the 4WD head...
Base 2WD head is backup
RS500 head is a refurbed showpiece item. Some one will come along wanting it for show car ( I have a spare RS500 base housing I could mount on it... just as a talking point)

 

BTW Linc, I had spoken to the guy that does drag cars that was one of DJR mechanics, he has a flow bench. So he is likely candidate. As for heads the guy who did my vans heads specializes in heads so I will go and check him out too. Then there is mercury marine... heard good things about them, but do they know Cossies... i think Aaron might have used them.

 

Mercury Motorsport not Mercury Marine. Heard good things about them too.

 

Oops freudian slip there , Could have ended up with an outboard engine.

 

Get back to work SLACKER!

 

I'm working from home today
Got to keep up to your frantic pace.

Hey forgot to ask, I could not find the main / conrod bearings... Did you send them ?

 

Thought I did!! Not there?

P.S. - rear housings on lathe tonight!

 

fantastic thanks mate