Chris's crossy head

[Clevo120Y 815]

And you need a tunnel ram for your ute too, I know of one up for sale very soon

[Tyler06 266]

I think you and sly have some talking to do and a tunnel ram sounds like something we can chat over when I come down ;-)

[Clevo120Y 815]

[Clevo120Y 815]

Chris's finished head flows 216cfm and is stable all the way to his lift point, this was tested with a stock 1.84in valve, the valves going into the head are a 1.86in with a back cut on the valve so the final numbers will be slightly higher.

Now to report my fuck ups with this thread, when I first tested these ports they pulled 231cfm and I was pretty happy with that because my test port only flowed 216cfm, the results didn't sit right with me for days as I couldn't see how the results were so different considering I copied the test ports dimensions over to this head, then when I was retesting a freak thing happened and answered why, my son was in the workshop while I was testing and he threw a tissue that went near the exhaust port of the head and the tissue got sucked in, the test spring that was holding the exhaust valve wasn't holding the exhaust valve hard against the seat and was leaking air giving a false reading, this happened at 150 thou of lift and above. Once I put some shims under the spring the results went back down to my test port figures. What this also means is that the results I got with the head before I touched it are also wrong as I used the same springs when I first tested it and the same thing would of been happening, so the base results recorded are too high, hard to say what they actually were but they were less than what I wrote down. Anyway the head flows good and will produce the power I was aiming for. 

[Clevo120Y 815]

50                 32

100               64.5

150               94.54

200               117.45

250               141.63

300               165.77

350               188.38

400               202.4

450               212.37

500               214.06

550               216.74

600               210.94  

[slydog 7,873]

Your WAAAAAAAAAAAY to honest...LOL Tell me I'm stupid please but I always wanted to weld the valve boss area up to allow a better shaped port and then machine in a new guide afterwards.Anyone else see this happening or ???

 

I mean it worked for my weber manifold so whats different hear but more work?

[ando76 4,354]

Yeah way to honest.  seen the same thing happen when someone forgot to screw in a spark plug.  awesome flow figures that time. lol.

the inlet swirl looks like it could have a bit more lay back to me but I could just be the photo. 

the bigger valve may help those high lift figures.  cam lift is big for a flat tappet and I can't help but thinking that the inlet trac could be opened up a fraction with the good (4 barrel) manifold.  All comes down to budget I suppose.  but that should be a fun package as it is. 

Nice work Sean.

[slydog 7,873]

Pffffftt big cam lift...your dreaming Ando That was good.

 

Actually gunna be interesting this time around.It made decent numbers with a less then perfect cyl head last time so this time it should scare alot more people.I think the power curve will be fatter the whole way though.

[PRO250 1,506]

Good work there mate


so the story here is a tissue is easy HP  

[Clevo120Y 815]

thanks guys, I would like to fill the back side of the guide boss and reshape/taper the tail, one day I will do it.

I've always said I would share my stuff ups as well as the things that go well, I never want to mislead people, I will make mistakes along the way hopefully not many HAHAHA.

I have also ported the Aussiespeed 4 barrel manifold for this head and flows an average of 204cfm with the manifold on so should go well. I agree Ando that the swirl wing could be layed back a little but I didn't want to change the compression of the engine, I may give it a light touch still.

Dave funny thing is the tissue has become part of my testing routine now LOL just to make sure there is no more leakage.