Darin Morgan, The valve seats, what works?

[Speedy Goomba]

What works for you guys in the area of the valve seats? Do you find that using stones over the typical serdi machine is prefered?
What seat angles are you guys using?

How many angles?

What angle back cuts on the valves?

do you guys radius the exhuast seats? is their any power gains with a radius exhuast seat?

thanks!

[Darin Morgan]

What angle back cuts on the valves? What ever the seat is minus 15 degree's.
45degree seat = 30 degree back cut
50degree seat =35 degree back cut.
This rule applies until you get into the 55 and 58 degree seats and then everything is out the window. Unless you are dealing with very high end engines that operate at extreme engine speeds, you will not need a 55+ degree seats.

do you guys radius the exhaust seats? is their any power gains with a radius exhaust seat? Yes we do and yes there is.

[Darin Morgan]

The seat angles we use are 55 to 58 degrees but conventional heads will not and can not use this seat design unless they have convex chambers and valve angles at or below 12 degrees. If you put a 55 degree seat on a conventional BBC head it will kill it.The chambers are not designed properly to take advantage of the steeper valve seat angles. We use a Sunnen seat and guide machine because I personally HATE Serdi's and will never again use one. The single blade cutters are the only way to go if you don't have a CNC cutter setup.

[Guest]

All right i found a friend in darin.Serdi in my view is the biggist piece of crap made.....






mike

[Speedy Goomba]

Thanks!

[Speedy Goomba]

I've had quite a few discussions about serdi machines, personally i find myself and the shop i work in to be always Fixing the work done on Serdi machines from other shops.

Do you stick with 3 angles on the seats, or are you using 4 angles?

If you dont mind me asking, how significant is the power gain of a radius exhaust seat.

Thanks!

[ozrace]

All right i found a friend in darin.Serdi in my view is the biggist piece of crap made.....






mike

Hey guys - I was wondering what it was that you disliked so much about the Serdi.
I used one for about 10 years and always found it to be a good machine. It requires a bit of technique to use properly, but after being taught properly and with a bit practice, anyone should be able to cut a good seat. Plus, you have a vacuum tester on board to check the seal before the head comes off the machine.
There's no doubt that if it's not used properly, it can cut bad seats, but that applies to pretty much any machine.

[Speedy Goomba]

Oz, the best way to tell if your seats are accurate is to use a Dial test indicator that locates on a pilot. I believe sioux makes it. Check the run-out on the seat and you know if its good or not.

[Guest]

I,am doing a flea market this weekend so when i get back i will get into why i don,t like the serdi and my experince that i had with a cup team that was going to by there valve grinder and after i got done with the serdi rep they bought something else.This was at PRI.







MIKE

[bill jones]

-I'm not trying to hijack this thread but while we're on the subject of seat machines:
-what is everybody using for valve refacers (brand name and machine model)?
-what tolerances to you allow in the runouts of the seats and the valves?
-What is the magic fluids you all use for the valve grinding fluids?
-What valve refacer machine wheels (brand and part numbers) do you use for doing BOTH steel and Ti valves?

[Speedy Goomba]

Sioux valve grinder.
Couldnt tell you the model number off hand, its very easy to use.

We allow a .001-.0015 runout, thats the amount which will still seal perfectly with tight guides.

[Wolfplace]

New guy here first post. Been reading along for a while & really enjoy the forum.

Hi Bill,
Believe I bought a couple of your books & your old multi drilled flow adapter a few years ago if this is the right Bill

My choice is the Kwik Way SVS with the precision air chuck option. This thing will take the bluing off the face of a valve
I've had it for about 5 years now & done nothing but clean it daily.
For Ti I use the Goodson Ti stone & it seems to be pretty fair.
Tried the Kwikway one & didn't like it at all.

On the subject of Serdi's, I have been using one (the 60 series) for over 10 years & have no complaints at all. I personally like it better than the Sunnen but feel they are both excellent machines so I will be looking forward to hearing why the Serdi is a "piece of crap" also??

My own opinion is the machine is only as good as the operator & either will do an excellent job in the proper hands.
It then comes down to personal preference as to which type you like & of course no one machine is going to please everybody.

I prefer the live pilot as I have found that tapered pilots sometimes tend to be influenced by the chamber end of the guide if it is not flat.
If it does influence the pilot & you cut the seat & them check the runout with this same pilot you are just amusing yourself as the centerline of the guide is not the same as what you are seeing with this pilot that is slightly askew from the influence of the end of the guide boss.
Just some thoughts from the new guy

Hello to Carl at CNC

[speedtalk]

Hi Mike, Thanks for joining the forum I don't want to start a seat and guide machine holy war, but I have to agree, the operator is the most important.

[Wolfplace]

Hi Mike, Thanks for joining the forum I don't want to start a seat and guide machine holy war, but I have to agree, the operator is the most important.

Thanks Don & thanks for the great book (740HP) great reading.

It took me about 10 tries to post this & I left a message in another forum regarding problems I am having
Here is the post:

Don,
Not sure what I am doing wrong but when I try to go to different forums or pages, I get a white page with what looks like html of the page or I get a page with part to the messages in html format??
It took me about 20 minutes to post in the engine section & now when trying to go from the main page to the engine or most any section sometimes I get there I sometimes I get this white page.
If I refresh the page sometimes it fixes it & sometimes not???
If you could also email me an answer it would help as I may not be able to get to your answer.
It took me about 5 tries to get to here
Thanks

[Speedy Goomba]

Simple, debur the guide first.