3 Angle Job

[nunoserrano 0]

hi could some one put pictures off a 3 angle seat job on a head ?? thanks

[petert 554]

here it is:

[nunoserrano 0]

hi petert how are you ???

 

for what i have understand the 3 angles are 30º 45º 60º right ????

 

thans

[petert 554]

See attached, but the bottom and top cuts can vary depending on the person doing the job, and how well they'll blend into the metal available.

[nunoserrano 0]

yes but after reading those they say that the head as from STD 15º then the normal 45º and then again 15º but what i whant to now is are all the STD head`S allready have the 3 angle ????? iff they have why send the head to make it again ??? or they send the head to make difrentes angles ??? iff yes what are they ???? thanks

[petert 554]

I've only ever seen one standard head done as per specs., but I wouldn't say I've seen as many heads as some others on here. It's very difficult to get the three cuts with the std. seat and valve size. There just isn't enough material. I personally wouldn't loose sleep over it, unless you're looking for extra hp. Fitting bigger valves allows the seats to be cut properly, but you'd probably do a 70, then 80 deg, then 90 deg. bottom cuts anyway.

[nunoserrano 0]

i have been reading the post on the bigge valves and seen your charts and since im going to start to building a 2.1cc engine in next year thats the reason im thinking on the 3 angle cut the engine its going to have jenvey 45 TB`s, haltech E6x, your repro Cam whit the #3 pulley and i was expecting to get 200hp from this engine so iff i leave the head std it will make me lose some hp right ????

[petert 554]

i was expecting to get 200hp from this engine so iff i leave the head std it will make me lose some hp right ????

 

You should see 200hp with a 2.1L, easily with big valves.

[nunoserrano 0]

right that what i was talking about if i what to get some hp from the head i have to put bigger valves and from what i have been reading here the size for the inlet valves are 36.4 and now its here thats my doubt starts were do i get this valves ?? and after fit this valves from what i have seen in your graph it will be better do a 20º then the normal 45º and finish whit ?????and this is for the inlet and for thes exaust do i have to put bigger valves to or the std ones are ok ??? and yes i now that i have to do a port job to

thanks

[petert 554]

The 20 deg. refers to the angle of the back of the valve, not the seat area, which is always 45 deg. If you're sticking with hydraulic lifters and a sensible rev. limit (say <7500), the std. exhaust valves will be fine. The exhaust valves/ports flow exceptionally well, the only issue is their weight. I wouldn't trust them at extended high RPM with hydraulic lifters.

 

The local 36.4mm valves I use cost approx. AUS$40 each. Pumaracing may well do a better and quicker deal. The ones I use have a single groove, which takes a Kawasaki Z900/1000 collet and standard Mi16 retainer. I'm not sure if Puma's are single or multi-groove, or what angle they are.

[B1ack_Mi16 67]

Puma bigvalve and standard mi16 valve.

They are multi-grooves and can use the original valvetrain components.

 

[petert 554]

Chunky butts aren't they! How much do they weigh? Interesting that they don't appear to be heat treated either. Perhaps they're made from a different material/process? I prefer the single groove. Sorry, can't post a pic. at present.

[B1ack_Mi16 67]

Chunky butts aren't they! How much do they weigh? Interesting that they don't appear to be heat treated either. Perhaps they're made from a different material/process? I prefer the single groove. Sorry, can't post a pic. at present.

 

They actually weight in a tad lighter than the standard-valve, but I haven't any exact weights. The valves are dished as you can see in the pic.

 

My enginebuilder have done some more back-cutting on thembut I think the seat-contact area is a bit on the small side after his work, but hopefully it's not a problem, I have no experience of how it's supposed to be.

 

[petert 554]

Mine have 6mm wasted stems and seem to have a lot less material in the head. Even with an extra 20mm longer stem, my 10 deg. samples weigh 58g compared to 62g for the standard valve. I have no doubt Puma knows his stuff however. He has plenty of runs on the board.

[PumaRacing 1]

They actually weight in a tad lighter than the standard-valve, but I haven't any exact weights. The valves are dished as you can see in the pic.

 

My enginebuilder have done some more back-cutting on thembut I think the seat-contact area is a bit on the small side after his work, but hopefully it's not a problem, I have no experience of how it's supposed to be.

 

Your engine builder should have left them alone and cut the seats in the head to match those on the valves. I spend a lot of time cutting the seat and backcut on every valve myself to exactly suit each application before posting them out only for people to bugger them up again before using them. The head won't flow properly with narrower seats than the valves originally came with. If there's one mistake I could single out that nearly every head modifier gets wrong it's to use valve seats that are too narrow. You posted pics of your head some time ago and I'm afraid the port and seat shapes weren't very good.

 

Mattsav posted some time ago that he'd finally got the Mi16 head to flow properly both at low and high lifts. What he didn't say was that it was only after getting a set of my valves and exactly following my specifications for seat widths and angles that he got it to work. Half the flow potential in that head lies in how you cut the valves and seats. Get it wrong and it just doesn't work.

[veloce200 3]

Half the flow potential in that head lies in how you cut the valves and seats. Get it wrong and it just doesn't work.

 

I guess the 8v head would be the same? Am I right in thinking that when you lap-in a correctly cut 3 angle valve that it will seat on the 30 deg and the 45 deg seat? I seem to remember D.Vizard on ASeries saying that the 45 cut should be around 1.5-2mm and that any bigger would lose flow? Does this apply on the Pug 8v engine? I'm going to be doing my own head (building a homemade flow bench - due to budget - there is none !) but definitely want the seats and valves cut correctly. Could I pay you for "Spec" that a local engineering firm could work to? Engine will be 8v, 12.5:1, PT28 Cam, Emerald ECU and initially std manifold (ermm budget again! ) I'm hoping for 160hp.

Edited December 22, 2005 by veloce200

[B1ack_Mi16 67]

Your engine builder should have left them alone and cut the seats in the head to match those on the valves. I spend a lot of time cutting the seat and backcut on every valve myself to exactly suit each application before posting them out only for people to bugger them up again before using them. The head won't flow properly with narrower seats than the valves originally came with. If there's one mistake I could single out that nearly every head modifier gets wrong it's to use valve seats that are too narrow. You posted pics of your head some time ago and I'm afraid the port and seat shapes weren't very good.

 

Mattsav posted some time ago that he'd finally got the Mi16 head to flow properly both at low and high lifts. What he didn't say was that it was only after getting a set of my valves and exactly following my specifications for seat widths and angles that he got it to work. Half the flow potential in that head lies in how you cut the valves and seats. Get it wrong and it just doesn't work.

 

Hm... not far from what I expected actually, as he doesn't have a flow-bench, so he really can't know how it flows.

 

Are the seat-contact area actually so small that it'll give me problem with overheating valves, or is it safe to put it togeather and see how it performs?

[PumaRacing 1]

I have no idea exactly how narrow the new seats are as you haven't said so I can't answer the question. My valves come with 1.7mm seats which is the ideal width for that head. 1.5mm should be ok on valves that size but anything narrower isn't ideal.

 

Worst seats I ever saw were on a pair of hillclimb Chevy V8 heads that a colleague asked me to sort out. A supposedly state of the art engine built in the USA and it had been built with 1mm wide seats on 2" plus valves with 400 lb valve springs. The seats had pretty much instantly hammered themselves concave on the valve and convex on the head leaving a rounded contact area maybe 0.75mm wide. Only the fact that hillclimb engines do very little mileage had stopped them burning out completely. Recut to 2mm wide (I wanted more but there wasn't enough material left on the seat inerts) and the ports reshaped the engine picked up another 80 bhp on the original 550.

[veloce200 3]

I guess the 8v head would be the same? Am I right in thinking that when you lap-in a correctly cut 3 angle valve that it will seat on the 30 deg and the 45 deg seat? I seem to remember D.Vizard on ASeries saying that the 45 cut should be around 1.5-2mm and that any bigger would lose flow? Does this apply on the Pug 8v engine? I'm going to be doing my own head (building a homemade flow bench - due to budget - there is none !) but definitely want the seats and valves cut correctly. Could I pay you for "Spec" that a local engineering firm could work to? Engine will be 8v, 12.5:1, PT28 Cam, Emerald ECU and initially std manifold (ermm budget again! ) I'm hoping for 160hp.

 

Any thoughts on this? thanks

[B1ack_Mi16 67]

Looks like the seats are 1.2mm.

[PumaRacing 1]

Any thoughts on this? thanks

 

I'm happy to do the actual job for you but I'm not really in the market for giving out specs based on my expertise for other people to try and follow which they probably don't have the right seat cutters for anyway.

[PumaRacing 1]

Looks like the seats are 1.2mm.

 

Ick

 

Good job I live a plane ride away from your engine builder. I don't take kindly to people butchering valves I've painstakingly designed and hand cut the seats on so that the customer has at least one thing that's exactly right for the engine that he doesn't have to worry about anymore. I sold you two sets though so don't you have spares you can use or did they get passed on to someone else?

[B1ack_Mi16 67]

Ick

 

Good job I live a plane ride away from your engine builder. I don't take kindly to people butchering valves I've painstakingly designed and hand cut the seats on so that the customer has at least one thing that's exactly right for the engine that he doesn't have to worry about anymore. I sold you two sets though so don't you have spares you can use or did they get passed on to someone else?

 

They got passed on to a mate of me, don't know if he ever is gonna use them, so I can probably get them back if I want to...

 

I'm just tempted to use the head as it is, and maybe get one of yours at a later time, maybe do a RR comare before and after

[petert 554]

Here's a pic. of a valve before heat treatment. Not a very clear pic., but you get the idea. Whether they flow better than Puma's only time will tell. They're certainly lighter though and combined with titanium retainers, they should be more reliable at higher RPM's. When I get it all the finished and weighed, I'd like Puma to run it through his calculator, if that's OK?

Edited January 4, 2006 by petert