Grinding valve seats - a question or two

radioFlyer55

radioFlyer55

Junior Member
I have an 8BA that I am rebuilding, and I wondered about the practicality of grinding the valve seats myself. I see that used seat grinders go for a couple hundred bucks on ebay, and the quotes for a valve job I have so far are in the $350 - $700 range. How hard is this to do myself, assuming new valves?

The info I have so far indicates that the intake & exhaust valve setups are identical, the only real difference is the use of a rubber o-ring on the intake guides. The valves are ground at 45 degrees, and the seats seam to get a 3 angle grind. SO:

1) Do new valves need a grind, or are they usually all set to go?

2) I am guessing I can measure the valve height with a dial indicator, and so get all the valves to sit at the same depth.

3) I do have 2 pitted seats (intakes), can these be ground out, or are new seats indicated?

4) what about these 1.6 chevy valves I hear about? how much more trouble are they to install?

5) I have what appear to be Isky lifters, can they be reused with a newer cam? They seem to have some wear visible.

6) I am not sure what the cam I have is, it has 0.335 lift for both intake & exhaust, I am pondering how to attach a degree wheel to the cam itself to learn a bit more. Is it practical to regrind a stock (or other) cam for a moderate performance improvement?
 
What do you want to do with your engine? If it's a street car for routine outings I would stick with a stock cam. A later '53 Merc cam would be the best overall performance if you can locate one. As to doing the seats, it's an easy job with the proper tools. A three angle job is not really necessary, as your not going to get any more performance out of it. JMHO. It can be handy though to position your valve seat properly on the valve face. Also to get the seat width in spec. Many people goof up here and let the seats get too broad. Getting them at the same height is a waste of time. Some people advocate grinding a new valve, but I never have done so, and it has never been an issue. Your pitted seats may be able to be ground out....depends on how bad they are. Grind them and find out. The chevy valves work well, but the 1.6 really is only helpfull in repositioning the seat if it is getting low. Performance wise, NADA. Your isky lifters should be OK, but you may be able to avoid the adjustables if you use the longer Chevy valves, as long as you do not use a reground cam, as the base circle will drop the lifters too much. Your old lifters can, and must be, refaced if you change to a new cam. Again, the stock merc cam is the best overall performer.
 
I get more satisfaction having control over my fate & doing my own stuff.
Besides having a Sioux set, I have 2 seat grinder motors that came in the cabinet with my B & D valve grinder. If you want I can get rid of an extra Black & Decker motor & stone holder. I only have one pilot for flathead, but could loan it, they come up on the 'bay all the time. You will have to get stones, I would get a coarse for the pitted seats.
Supposedly truck motors had all inserted seats but the BA's had only exhaust inserts? I ran a resurrected motor OK for a while but the compression coming back into the intake does not let it run well, I could get all the pits out and saved it.
The lapping compound really tells the story, when it finishes to where the gray line is complete on the valve and seat all around it'll seal.
 
1. Usually acceptable but I always check them.
2. As stated above, a complete waste of time and material.
3. Depends? How bad are the pits?
4. The 1.6 valves are allot of extra work if done correctly.
5. Lifters must be reground before applying to a new cam or swapping locations on a used cam.
6. Almost any regrind will only help high RPM performance at the expense of low end performance. Follow above advise and stay with a stock Merc cam unless you intend to operate most of the time above 3000 RPM.
 
When I was a Ford mechanic back in the 1970's I was lucky enough to be able to bring in heads and use their B&D machine anytime I wanted . I wish I still had one so I could do the head work myself . It's not hard to do at all as long as you take your time and set everything up right the first time . Then I would lap the valves and put everything back together .
Now as for cost , unless you are going to be doing a lot of valve work it really wouldn't pay to buy the seat grinder and stones along with a valve grinding machine . The machines are very heavy and take up a lot of room . You can get some good deals on ebay and some auction where schools get rid of their old machines . But to brake even you will have to do at least 3 valve jobs .
I really agree with the do all you can by yourself . There is no better pride in doing it your self .
Another thing to consider is with all the trouble flatheads have with cracks , I would recommend having the block magged for cracks .
If someone has one that you can use or rent some time to use one that would be a much better option .
Good luck with your build !

Jim
 
I have a friend that has the equipment so I was able to do it myself. I kept each guide with the seat I used to grind it. 3 angles allows you to narrow the seat and position it on the valve. A narrow seat will give you a good seal with the spring pressure concentrated in a smaller area but you lose some of the cooling effect that is necessary for longevity of the valve. I used stones this time and kept them true. In the past I have used Neway cutters and they are much easier. I have limited experience but it starts up easily and I have over 2000 miles on it so something must be right.
Here is a link I think anyone can look at. I do not think you need a facebook account.
http://www.facebook.com/#!/album.php?aid=123468&id=590113611
 
Most good quality aftermarket 1 piece valves are ok and will runout .001/.0015 TIR wich is good enough, however I have seen them out at .005 TIR. I would recomend having a shop do your seats; you'll probably save time and money. 1.6" valves are not necessary. I'd follow JWL s advice. jmo
 
Your questions about valves they will be good out of the box but should be checked.

Installed height tough one on a flatty requires a little tooling no return on investment.

Pitted seats usually clean up hard to tell without seeing.

1.6 valves why bother if your seats are good.You will need a little coaching to do that one.

Just pay a shop to do it. The ebay kits can be ok but you won't know what you are getting. It won't have a Flathead pilot unless you are lucky.It will need a tuneup.

The lifters need to be reground for a different cam. Finding a shop with a machine will be harder.

I use neway equip for flatheads much easier to control quiet not messy. I don't use my Sioux equip for that job.

3 angle job not required done rite you are going to have a 2 angle anyway.

Spend the 300 plus for the job and put your money in good parts unless you don't mind learning you will need a good coach to get it all together for your first valve job.

I hope this helps you in your Flathead journey.
 
One more thing . . . . if your 8BA block is a '49 or early '50, it will have hard seats in both the intake and exhaust.
 
ONE thing: don't learn on this engine!! If you decide to, get ahold of some cyl head cores, cheap...
I have and use Neway, a seat cutting system... The B&D stones will do a good job, but there are a lot of pitfalls... Find someone who has one, and has used it a lot- to teach you- use junk heads. Some good advice above, also... Contact me if you wish...
IMHO... Karl
 
Thank you all, this is encouraging. I have been over to www.cylinderheadsupply.com looking at Neway tools, it seems that this is really quite affordable, a solid guide costs about $22.50, a cutter head costs $67 - $100, and a T wrench costs $9.25, and that is about all that is really needed.

I checked their user guide, and they recommend that for a 45 degree valve, the seat should actually be cut at 46 degrees, and in fact most of the kits on ebay seem to have 46 degree cutters (and the 46 degree is 2/3 as expensive as the 45). Any thoughts on this?

Also, they have a number of different 11/32" guides:

1) A 150 series expanding guide that goes from 0.003" under to 0.017" over
2) and 14 140 series solid guides that are tapered and go from 0.006" under to 0.015" over.

I am thinking the expanding guide is the way to go on this.

Also- this block has inserts all around, and I will be going pretty easy on the engine.

Thanks.
 
Nope you are already going down the wrong path.

Those are pilots you are referring to not guides.
You need to measure the seat width as you progress along so get a good vernier dial caliper to aid you in measuring eye sight not good enough.You also need to check where seat is on valve till you get it done correctly on the first one requires some delicate measurement to make it nice. You have to repeat this 16 times so get the first one correct.A felt pen will help you here.

11/32 pilot won't work you need a pilot for a Flathead. It is 1" 1/32 and a tapered fit. Now that will have a .375 top won't work with Sioux tooling they are.385". Make sure you order cutters that are .375" hubs not .385" or .4375" They are available many ways. See how easy this is.
Call back for that price much more than 22.00.

You "may" also need a 60 deg cutter if the seat becomes really wide another expense.

The guides fit too loose to use a 11/32 pilot and get a reliable nice seat unless you loctite the guide and don't plan on taking it out until next rebuild, then you could glue 16 guides in and go with a expanding pilot 11/32" pilot. Now valve train assembly is another story as the guides are glued in. You will need more than a 45 deg cutter .Chances are first time around you will get the seat too wide now you need a 30 deg cutter to trim the top. The 45 and 46 cutters are called interference angle not that popular any more go with 45 on seat and 45 on valve done every day easy.

Ask away for more info this should keep you going for a while.
Ps just a small not if you use a solid pilot how are you going to get it out of guide think about that its not hard but ask the guys where you buy this stuff if they can't tell you don't buy from them.
 
i went into my local napa store here that has a good reputaion for rebuilding engines, and asked the shop guy if i had to remove my head studs ( from my `46 ford flathead) before i brought in my block for a valve job. or could their grinder reach past them?
i might as well of landed in their parking lot in a flying saucer and walked in speaking a language from another planet!
when i got past him thinking i was some kind of idiot, and explained that the valve seats were in the block - not the heads. he told me if they can't set it up on the bench like they do cylinder heads, they wouldn't know how to do it. i told him that they had done one for me about 30 years ago. he pointed his foot at an old dusty box under the bench, and said: oh, that must be that thing... but i wouldn't know how to use it.
that's when i knew for sure i could do a better job myself, and bought a used grinder on evil bay and did my own. seems to me you have already done quite a bit of research, i think you'll do a fine job.
i didn't want to use the 1.6 valves, because i thought i would need bigger seats. some of mine were pitted also, but they cleaned up o.k. i would rather try to save the original pressed in seats instead of taking the chance of repressing a new one.
you will have to get a stone dresser, so you can redress the wheel.
i bought all new valves, that way you don't bother regrinding valves. you can lap them in to be sure you have the wheel dressed at the same angle as the new valves. slight lapping will show up any miss match.
exact angle isn't as important as an exact match.
 
radioFlyer55 said:
I have an 8BA that I am rebuilding, and I wondered about the practicality of grinding the valve seats myself. I see that used seat grinders go for a couple hundred bucks on ebay, and the quotes for a valve job I have so far are in the $350 - $700 range. How hard is this to do myself, assuming new valves?

The info I have so far indicates that the intake & exhaust valve setups are identical, the only real difference is the use of a rubber o-ring on the intake guides. The valves are ground at 45 degrees, and the seats seam to get a 3 angle grind. SO:

1) Do new valves need a grind, or are they usually all set to go?

2) I am guessing I can measure the valve height with a dial indicator, and so get all the valves to sit at the same depth.

3) I do have 2 pitted seats (intakes), can these be ground out, or are new seats indicated?

4) what about these 1.6 chevy valves I hear about? how much more trouble are they to install?

5) I have what appear to be Isky lifters, can they be reused with a newer cam? They seem to h
6) I am not sure what the cam I have is, it has 0.335 lift for both intake & exhaust, I am pondering how to attach a degree wheel to the cam itself to learn a bit more. Is it practical to regrind a stock (or other) cam for a moderate performance improvement?
Click to expand...

m
Might be off base, but seems way high, considering you can by neww valves, lap them in for 1/2 the price
 
I would not try to get by with just lapping new valves. Valve seat grinders show up frequently at swap meets. I would look for one, and be sure it comes with a stone dresser. . I also would suggest you go with stones, and not cutters. Far more friendly to use. You would probably need to buy a new stone holder, as they get sloppy on the pilots. Be sure your pilot fits your stone holder. Get all three stones 30/45/60, they are not that expensive. Trust me, you can do this with the correct tools. I did it the first time at the ripe old age of 16, which proves any do it your self mechanic can do it. Get some Prussian Blue also so you can easily see what your doing. Go slow and easy untill you get the feel for how much material you are cutting.
 
Don't lap new valves to uncut seats very poor choice.
Be careful if you buy Sioux check it out well they have gone out of business.Getting harder and harder to get replacement parts for older machines,still a good setup just poor support for parts replacement.
 
He has mentioned that he has some pitted seats. He also has told us he has hard valve seats installed. He will get more valve wear than seat wear by lapping. Not to mention it would take FOREVER that way, with inferior results. If the seats looked good, Lapping new valves would be an option. Such is not the case.
 
First, follow JWL's 6 point advice.

After that I would add, IF you can afford to have the valves done at a
REPUTABLE and I repeat REPUTABLE commercial shop on a modern valve machine, you will get the best job available anywhere. It can be as many angles as you want, it can be 30 or 45 degree etc etc....The seats are MACHINED with a carbide cutter, on a RIGID arbor, not ground with a loose fitting stone holder on a many times worn arbor.
The valves are VACUUM checked in the holes after they are ground, for perfect seal.
This is modern technology available to Joe Blow in most big cities.
 
I recently had a very experienced friend help me try to recover my pitted seats. He brought his old B&D machine over and it was fun working with and learning from him. Long story short since my engine had sat so many years the pitted seats where borderline at best after grinding. The block is at the machine shop right now having the seats replaced.
 
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