Thread: Kelford 184-C on the Dyno - Progress so Far.

pm sent

The angles used on the valve grind are determined by the lift of the cam to be used & the required rpm range & capacity of the engine. That being said the VE heads lend themsleves to higher rpm operation & cam lift between various grinds does not vary a huge amount - so the angles I used will work for most serious performance applications.
Another thing to note is that the cut angles are only a starting point, I vary the widths & blending of the cuts by hand at different points around the seat, the finished angles & widths are very different on the long & short turns as well as the bowl sides, so simply stating the angles & widths that I cut on the machine doesn't really describe the angles & widths on the finished head (if that makes sense), they are simply a starting point.

For what it's worth:

Intake
80 deg throating/blending cut to 85% of valve size, 60 deg bottom cut, 45 deg seat, 32 deg top cut, 15 deg chamber cut, radius into the chamber wall.

Exhaust
Full radius into the throat, 80 deg blending cut to 87% of valve size, 45 deg seat, 35 deg top cut, 15 deg chamber cut, radius into chamber wall.

Ok very nice of you to post this info. I'm going to talk to my head guy and see if he can take this into consideration

Yes sir thank you very much for being so forthcoming with all of your information! You have no idea how helpful it is.

That said everyone else do your part and give credit where it is due when the time comes.

Dudeman

Having hang around a lot of cylinder head shops, I know how much time and thought goes into the valve seat angles. It one of their most guarded secrets, and so I think TK383 is very generous in posting the #. But please don't take advantage of his generosity.

The way I see it if a head shop is good enough to get the porting right then they'll know the angles to use - if they need to be told what seat angles they should be using then chances are they don't know enough to port the head properly.
Seat angles & port/bowl/window/short turn shaping go hand in hand, get any part wrong & it won't flow, it'll go turbulent, it'll choke or it'll lack suitable velocity, any of which will kill power.

^You work for a shop?

I own the workshop.

hey tk where are you located and how much did the port work on the head cost if you dont mind sharing

Best to get in contact with DDSC performance - he paid for the development time so it's only fair that you go through him.

I do head development for quite a few companies, with that comes the requirement of honesty in dealing with the general public - if someone pays me to develop a port profile then although there is no contract I feel it is ethically right to do any further identical jobs through them.
If I'm just doing a port job on a head I haven't done before I usually just do the testing & R&D off my own back & use that knowledge in any subsequent customer heads, but if I'm being paid for that R&D time that's a different matter entirely.