Valve Job Info

Information about valve jobs. Not all the info

[timothyarnott]

Hey Eric,
Tim learned cutting seats with a stone (circa 1982), in auto shop we cudda had proper cutters, in auto shop, you wen't learning hi-perf stuff persay, it was make it useable for a daily i did ALOT of heads in auto shop, cuz i was good at i always wanted to know i've known for YEARS now about angles, chatter, vid is CRUCIAL for younger folk, just gettin MUST learn about chatter marks, and how to address for performance a GREAT just LOVE is to you sir!!

[markdavis]

Watching this video took me back to my teen years.i remember going to a junk yard and buying a set of coveted 906 heads for my 440. When I got them home and started cleaning them up, I saw they had about a half inch of carbon on the valve stems. So I pulled all of the valves out and wire wheeled them and then putting them back in, in no particular order and lapping them in. The lapping seemed like way too much work to do by hand so I had a bright idea, why not just clamp a drill to the stem and lap the shit out of them by putting some compound on them and giving a good long pull! Surprisingly the car actually ran pretty good! These are the things s teen with no money, little knowledge, tools and a desire to go fast do.

[budlanctot]

I have a really good set of pilots, stones, and stone holders. I used to do a lot of heads the old way, years ago, and I think I was pretty good at it. On several occasions, I was approached by some car owners, unhappy with the way they're cars were running. On a couple of those engine rebuilds, I diagnosed leaky valves. Both were done by (then)new form cutter machines. I reground the freshly cut heads with my old school Sioux seat grinder, and had them running much better. Now, don't get me wrong, if I had the money for a Rottler seat machine, I'd rather use that. I guess my point is that it isn't just the tool, it's the operator who runs the tooling. He has to take the time, and use proper care to not feed the cutter too fast, or run the cutter speed too fast to avoid chatter and tool deflection. And he's responsible for closely checking his work. I used to check all my valve jobs with a Sioux vacuum checker. I also used an adjustable seat scribe to help get my seats the same height.

[mikeolson]

I've been using the Neway valve seat cutters since the early 80's (3 angle)for Atv, Motorcycle and marine Cylinder heads.Seem to work decent and I always leak test my work.i would love to have a serdi, newen or rottler but I'm semi retired nowadays and even if I purchased a nice used machine I doubt I would be working long enough to make it worth my time.ive sent off a few heads to have seats replaced(I do the guides myself)and was very impressed with the work, especially the radius type cut on the exhaust seats, very nice.i enjoy your vids young man, keep up the good work.

[Halfrightfox]

Great info for a young engine enthusiast like myself. Thank you for clarifying all the misconceptions and providing us with your wisdom

[hotrod]

OMG I still have my Sioux stone grinder sitting in my garage. Looks almost exactly like yours. I run an IDL valve seat and guide machine. But certainly cannot cut as much as you just have to go slow. Loved your video Eric. That was a great idea to stone lap those chatter marks 👍🍻🍿

[kaboom]

I was always taught that lapping is for cleaning up / freshening the seat and seal, but, to go ahead and spring for a real valve job after a couple times lapping them .
Stones will always have some utility, no matter how good a milling machine gets .
I wonder if the chatter is also partly due to variances in the hardness of the seats ?
Easy to imagine that the hardening process may not have been done as well as it could have been, and / or the composition of the seats is not as homogenous as it should be .
Everything isn't as well controlled and consistent as we would like it to be, even with all the technology at our disposal these days .
Really makes you appreciate how good the old guys were, and what they could achieve with what they had available .

[kellyjones]

Back in the day I used stone cutters. I did a 3 angle valve job. It took time to do a good job.

[deanmoser]

Good video. I worked in a small head shop in the early 90s here in Australia. We got one of the early small Serdi machines and had stones too. We weren't as fussy as you back then but everything you said was 100%.

[tadeckel]

You are so right about lapping. Another issue with uneven seat is uneven heat dissapation. Good info!

[taylorboultinghouse]

Ls cheap guy here. I've been working with some factory Ls7 head for sometime now. Had a couple of machinist look at my heads and none of them said there was issue with my valves. I've dropped 3 valves. Looking at the price of having the work done I'm going to do the work myself.

Thankfully with this being a project car, I can take my time. Replace the guides, use a dingle hone to slowly arrive at the right diameter, and lap the valves in. Checking the guides with a bore gauge as I go.

I am chasing titanium intake valves dropping. The issue seems to spur from GM not machining the valve seats to be concentric with the valve guides. Causing excessive wear on the guides. Also keepers wearing on the valve stems to the point the valves fall

Thank for the quality information! Good luck spreading the good word.

[DiscoGreen]

I ground cranks for a few decades chatter from a stone was usually a wheel that needed dressed.. but sometimes was the machine was getting slop.. make sure the machine bushings aren't getting old when youre on left side.

[dondotterer]

Yep.years ago I went to a seminar AT UNOH in lima Ohio. Learned alot about the importance of valve jobs and wet flow from Darren Morgan and Joe Mondello.The Engine masters Challenge

[fluxcapacitor]

As a teen in mid 80s we had a multiple auto parts stores, a garage & full service auto machine shop & stones were a way of life for our cyl head guys in those times & one of the guys had it down to a science, we preferred stock & industrial head & block work but 3 of us 16-35 year olds had race cars, we sold out after 30 years & stayed in parts as an independently owned in a box store world, at time of selling the machine shop equipment an older worker said ain’t you gonna keep that stuff & I said nope once you see the 5 angle cutters we had used the last few years in the mid 90s in the Peterson Seat & Guide machine it’s the only way to fly. Never a stone cept to touch up boo boos in our race heads. Excellent video Eric brings back memories ! I’m Saving up for a set of sbc heads to buy from you bare & using your advice on what quality stuff be best to build them to with meet my needs. I was wondering if emailing you be best when I’m ready in a few weeks as I know all about drop what I’m doing & tending to the phone, as I do throughout the day, as Dad told me don’t bite the hand that feeds you. “Appreciate your attention to detail !

[timsane]

Good info here Eric! Many People think wrong about valve jobs and do underestimate their importance. Nor can they imagine how difficult a precise seat cut is. We are using the Serdi Stronik CNC since January. It is a DREAM and to be able to adjust each angle, width or radius makes it priceless. Best „PlayStation“ i ever had. Keep up with your great videos, all the best from germany! Tim

[lauriegregorylgregory]

great video eric, love your stuff.one thing you can try, because i did this in the 80s & 90s, with a new mandrell & pilot (which i notice you have)put a spring between the mandrel & the guide which slightly holds it off the seat.use a very fine stone & when you sharpen it go slowly.spin it up & just lightly touch the seat.which removes very little material.i was very good with stones because that is all my shop had but i did drag race & circle track stuff, then vacuum tested & had good results.even though i dont do machine work anymore im still very interested in it & still occationally do some port work & getting ready to retre from my job now & going to get into racing work as i did machine work for 7yrs.

[erickieffer]

Thank you for having the guts to talk about chatter and being honest about how it happens to everyone.

[defbysunrise]

I've never used lapping to fix anything, only to confirm how wide the sealing surface is against the valve, and to confirm it's position relative to the valves outer edge

[tippsy]

Thanks for the info Eric this is the stuff we want to see! Not only showing why you do things but showing what will happen if you do things differently!

[bobbybieln]

I noticed with the single point cutter it's performance in producing a round (centric) and chatter free is the valve guide clearance . I had used the serdi valve cutter and it was tough to get a even cut . Seemed to want to dig in, and messing things up on me.