MTFCA Forum

I thought the valve guides could be reamed with an oversize reamer WITHOUT removing the camshaft and lifters. But obviously I was wrong! Also, I expected the exhaust valve at the number four cylinder to be accessible WITHOUT removing the wooden firewall , or pulling the entire engine!!?? But it was not!
Any valuable hints?

I cannot imagine why you cannot ream valve guides with lifters in place... A shop towel draped into the valve chest will direct metal swarf out and away from the engine

Yes, things get tight near the back...not that big of a job to remove wood firewalls...or scootch the engine forward a bit...

as for reaming, be darn sure you have guides that will sufficiently locate the reamer or you'll likely move the valve's head off location and then you'll really be in for more of a job than necessary

as for grinding and lapping the seats, that's just a good way to ruin new valves. A Neway cutter will do a clean, quick and accurate job...with no grinding or lapping necessary.

I think all the valve guide reamers sold by the Model T parts suppliers are spiral fluted. However the lifter guid reamers have straight flutes. Beware of these. It is very easy for straight fluted readers to ream a significantly oversize hole .

I was warned of that so I took extra care and mounted my block on a mill so I would be insured of a 90 degree cut. The end product was a mess. The bores were 12 thou over what they should have been due to flex or chatter. I was shocked and in disbelief until I measured a few times to conform the bad news. The fix was to bore the lifter bores oversize and install bronze sleeves. I purchased a piloted spiral fluted reamer from a machine shop tooling supplier to finish the job.

Two years ago, I reamed the valve guides with the engine in the car. The wooden firewall was loosen, but not removed. I made a guiding fixture to maintain reamer alignment. I had excellent results.
The reamer was purchased from a well known and respected supplier.

Art Mirtes

I will be performing this task in the future and wonder where the guides are available? I do not have access to a metal lathe to fabricate my own...yet.

What size Neway cutter do I need to purchase for my T's? bobt

I use the Neway 205 and 636 cutters. These cut 60, 45 and 30 degree angles on the seats.

You will also need several pilots as the reamed guides will typically vary a bit. Neway guides come in .001” plus and minus increments along with standard sizes.

As far as reaming the guides themselves, here are some photos of the Stevens outfit to give you some ideas about the fixture can be made.

bobt

honestly, as far as procuring Neway cutters, the best thing is to call them. One of the fellows there is acquainted with our cars and will in fact be able to advise on the best cutters or cutter combinations to purchase. Brent's advice on the pilots is correct...you'll probably need more than one...I've tried Neway's expanding pilot and cannot get it to work repeatably, while the solid pilots are just that...SOLID and repeatable.

always send out new valves to be kissed again just to be sure there is no handling damage and that they did not somehow become slightly bent...then (with respect to Trent), while the valve face is indeed 45 degrees, the seat is cut to 46 degrees (not 45) and then clearance angles of 60 and 30 to "raise" or "lower" the seat as necessary.

you cut the seat at 46 degrees for a knife edge seal initially and then after a few seconds of running, the valve moves the cast iron just enough to form a perfect seat. Neway recommends you do NOT lap the seat, and folks who insist you do need to, are expressing their personal opinion and not the advice from the company. I follow Neway's advice and always have excellent results.

Petra

guides are not commercially available, that I am aware of...I made my own

Lapping new valves into refaced or new seats can cause issues. For one thing, the lapped area on the valve face will only be a narrow band, not the full face. When you start the engine, the valves, especially the exhaust valve, will rapidly heat up and expand, which will tend to move the lapped portion of the valve face out of register with the contact surface on the seat. This can cause leakage. The exhaust valve will run hotter than the seat under almost all conditions. Aggressively lapping the valve face against the seat will actually cut a groove in the valve face. Once the valve heats up and expands, the groove will not match the seat.

the new way set you want is their small engine set be sure to order the correct pilot

Taking Philip's information I looked it up...there are actually TWO kits (at least) that are labeled "small engine"...of the two, Neway LG2010 Valve Seat Cutter Kit | Small Engine | Stens 750-289 | Rotary 1741 appears to be one that would work. The other kit lacks a cutter you'd need.

That said, the kit includes lots of pilots for numerous valve stem diameters. These things are not cheap and you are definitely paying for pilots you can't use on a T. For the money (or less) I stick by my recommendation to call Neway and get EXACTLY what you need without extra pilots and such that you'll never use. They know what you need and will fit you up with a dandy kit.

Because they rely on replaceable carbide cutters, I would personally avoid buying used on eBay, as you really cannot tell the condition of the cutters. If, on the other hand, it is a screaming deal, you can buy a used kit, jettison the cutters and buy them new and MAYBE come out ahead, but this is one place I spent the $$ for new, and have maintained them as such for many years...$$ well spent, in my book.

Whatever you do, if you are searching eBay, don't fall for the crap India-made carbon steel cutters!