MTFCA Forum

Well, it’s official, my valve guides all uniformly mic out to .314
My newly purchased .312 valves actually mic out to .311, so 3 thousandths across the board!
My research indicates that the rule of thumb for valve clearance between valve stem and guide to be:
Intake 0.001-0.003
Exhaust 0.002-0.004


Still seems like a lot of sideward movement in the valve guide to me…..thoughts?
Frosts my backside to think that 0.015 over is my first option should I elect to drill in ream just to gain a couple of thousandths!

Thanks in advance!

Cheers!

Is your T expectations high or low? Plan on freeway driving or putting around to get ice cream? Going with new valves & a lap will be adequate. Maybe a little extra smoke after idling @ a light. Controllable somewhat by not over filling the oil. Personally I would knurl the guides. Does require removing the lifters, but not pulling & tearing down the motor. Your decision.

right or wrong, I map the guides to take 6 measurements per guide: top, 0 and 90 degrees, middle, same, bottom same

you'll usually find a bit of an hourglass shape in the guide and I'd bet that's why you are showing not terrible wear (in the middle) while still having wobble?

from what I recall, your engine was in pretty good shape? I might be inclined to cut new seats and plop in new valves...with the wear you're describing, you will go a long time before it becomes smoky. Not all refreshes need to be extensive or expensive.

since you're going with a new cam, treat yourself to new adjustable lifters...they will almost certainly still be OEM size.

Flyingpiper59 wrote: ↑

Tue Jun 13, 2023 10:29 am

Frosts my backside to think that 0.015 over is my first option should I elect to drill in ream just to gain a couple of thousandths!

Thanks in advance!

Cheers!

You don't need to gain anything. You're "In Tolerance".

Thanks gentlemen….You confirmed my sentiment…. New valves it is ……cut the seats with the new way cutter…. The camshaft is being re-ground and the adjustable valves lifters are already on the bench… a few folks had said that 3 thousandths was excessive…. Thanks for talking me off the ledge…..Lmaoooooo!

Not that you have to do this...

I always take the valves to my engine guy and let him kiss them to assure that nothing got knocked out in handling. Once perfect at 45 degrees, do a 3 angle seat with a 46 degree seat which will "pound in" in a few seconds of running for a perfect seat. I consider things done when I can print a perfect ring with prussian blue. Don't end up with too wide of a seat...use the other cutters to raise/lower the seat as necessary and to bring the actual seat to the correct width.

If you don't own the kit already, don't waste your money by saving money on eBay...none of those kits will have all of what you need. The cheapest course is to contact Neway directly and tell them what you're working on...they know Model Ts. Given a choice, I highly prefer the solid pilots over the adjustable pilots for repeatability and now that you've measured your guides you are certain to purchase the right couple of pilots for your job.

Will do Scott…. I just purchased what I guess is the deluxe version of the new way cutters, almost $300 with shipping…… I guess I gotta cut out my cigars for a couple of months…lol