ltd351

Heya all

The shop I took my heads too just for a service were trying to tell me that a 3 angle valve job means 3 angles on the seats but only one angle on the valve, I was always under the impression that the valve would have 3 angles as well. Are they lazy or am I wrong?????


On a good note it seems the heads are very very nicely ported.

pracy

its only on the seats, i think its more about flow into the area, not how the valve is sitting.
I mean the 3 angle on the seat, is cut for flow performance, therefore aslong as the valve sits right, then only 1 angle is needed on the valve.

Tones Teo

Howzit - I think your machine shop is correct.
A three angle valve job refers to cutting the valve seat & area either side of the seat face at different angles to reduce turbulence and smooth out the flow.
The valve touches the seat on one angled face only.
Sorry if the last part sounds like gobbledegook!

Cheers

__________________
"If it's got Tit's or Wheels it is going to cost you money"

crochunter

3 angle valve seats are a thing of the past now. They use 6,9 and have heard of 12 angle valve seats.

ltd351

Thanks lads. Would an extra angle on the valves help at all?

xdclevo

I know people talk about "backcutting" the valve to a certain angle(30 or 33 degrees). The best thing is try and get a good 3 angle cut on the seats if possible, but the cleveland head doesn't allways allow it. I know my 2v heads would'nt completely. It's probably not a major concern in forced induction anyhow.

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10.70 @ 125.00 on the black fun top
408 Cube Cleveland.

Tones Teo

Are 3 angle jobs a thing of the past or just that there are other options available???, surely grinding multi-angle or radiused seats would cost a lot more without showing any real benefit to most of us.
I would think 3 angle valve jobs are still widely used in Street/Performance
applications???

__________________
"If it's got Tit's or Wheels it is going to cost you money"

ltd351

Yeah the shop I did some time at always put the extra 30deg cut on the valves, thats what I told the head builder to do with mine, can't hurt anything I wouldn't think.

ltd351

I am by no means an expert but i was thinking that most people who use the stones or cutters to do the seats have the 3 different angles but the blokes with the big complicated machines can prob do more angles with only a little bit more time, I don't know if that is the case just what i thought. The guy next door does top notch rally engines and he uses 3 angle so it can't be that bad.

paull

I always thought that as the valve face temperature changed, so did the angle of the face. In that, with the three different angles on the seat face, a proper seal was maintained at all times. Am I wrong?