discovered too late my 8ba didnt have valve seats in the intakes. local machine shop said it was scrap. hate to scrap it as its ported, lightly relieved, and bored to 3.5/16. also, it didnt run hot. can it be saved, and if so, whats the best way? same shop also said the flywheel was scrap, i know it needs a ring gear, but is it too rusty? btw, this is a mild build, merc crank, mild cam and 2 94's and mallory d.p.
Wow...beat up pretty good. If the holes weren't there, you could still remachine the seat area and install seats. But with those holes that "look like they go into the water jacket", I'd say you're outta luck. Mike
What caused that carnage? A 3 lb hammer and a chisel? Was the goal to try to remove seats that weren't there?
The block is ruined, period. Flywheels are not hard to find. I wouldn't trust that ring gear. They are easy to replace and not that expensive. Getting the thing cleaned up, surface ground, new ring gear and balanced would cost more than it's worth. Get a new one from Speedway. They are 12 lbs. lighter, to boot. In the future, leave the valve seats to the machine shop.
Make up some oversized valve seats and press them in. Many machine shops might not want to take it on due to the time/effort/risk, but anything is repairable.
Flywheel is easily repairable, new ring gear would be sensible, but may or may not be financially worthwhile if you're paying someone else.
When cutting for insert seats you can go into water. Not ideal but it happens all the time in some applications. It generally sucks more to do any valve seat work on a flathead, it's not different though. Good luck. Mike
Chalk it up to a learning experience. That block will be expensive to repair since you drilled through the ports below the seats. Find a new block and don't do anything to it yourself. FWIW, that block also has not been relieved. That's not really suitable for a valve seat.
ok, in my own defence, this aint my first rodeo on valve jobs. just my 1st flathead. and have never run across a seat in block before, thats what i get for assuming. i do have another block, and appears to be untouched, and it has insert seats in all valves. as far as the relief, i said lightly, this car was first built in the late 60's, and looks to me like the previous builder may have used a sanding disc. maybe he should have had someone else do it.
If removable valve seats aren’t big enough to get rid of the damage, have the block welded then remachine the valve seats, way worse has been repaired
Sandblast that flywheel, new ring is available. Warm up the new ring and drop it on. Holes in block can be welded with nickel rod, (more 'modern' ways of welding are now available, too) Have the holes welded up and grind new seats in. Too many folks throwing too many vintage parts away will result in...Not enough stuff!
I say take the loss, put the $$ towards the other block. A repair that “lasts a lifetime” would probably be in the ballpark of starting over.
That's not really suitable for a valve seat.[/QUOTE]. https://www.enginebuildermag.com/2015/04/engine-block-and-head-repair/
If you're considering that block as scrap, why not try to repair those holes at home, and then test them to see if it's good. Just out your time, and some type of material(weld, stitch, etc), but if it works, you've learned something new for your repertoire. I'd give it a try.
as stated earlier, i do have a good block, probably will go that route, but agree with you, if its truly scrap, i have nothing to lose.
FWIW, those suggesting just sticking in valve seats should clarify. One might get away with a valve seat installed over a hole going into an intake port. One installed over a hole into the coolant passage is more likely to leak than not. I've been doing this for sixty years and I wouldn't try welding up a flathead V8 at home. There are still a few places I'd trust: Cast Iron Mike Cast Iron Repair Specialists 16129 Smokey Point Blvd, Ste A, Marysville, WA 98271 360-657-7660 As to cost, it'd be a wash between having all the machining done on a new block and having it redone on an old one. To do a weld repair properly, the entire block has to be heated and then slowly cooled. After that, everything has moved around and so a line hone sweep of mains, clean-up hone of cylinders, new valve guides and seats. BTW, until your "new" block has been cleaned, magged and pressure tested, don't assume it's sound. Seen way too many which looked good at a glance and had lotsa cracks. As to sonic testing, it's better to know than not know, but it is likely to miss internal corrosion and pits, if they exist. On a block of the type we routinely bore .117" over, we had a cylinder open a hole at .080"; most likely an inclusion in the casting which rusted more than the rest of the cylinder. The thing which gives me nightmares is the weak spot which doesn't quite show up, but will blow out under compression or coolant system pressure. jack vines
Question on a recently installed exhaust valve seat on a 51 Mercury 255 Flathead. The seat in question is higher than the rest, all 15, so part of the seat has been plained off by the head surface of the block. See photos. The contact patch on the valve starts near the top, outer edge of the valve, and not in the middle of the valve face like all the others. Also, the contact patch on the seat is almost being shaved into by the plain of the head surface of the block. Machine shop says this is OK but to me, it seems like the new seat should match all of the others. I would think this valve will also sit a bit higher than all the other valves. One photo shows the seat in question with part of the intake seat to the left. The other is the exhaust seat next to the one in question (part seen to the left) . These are the two center exhaust seats. Thoughts.
Just because it was shown in a photo in a magazine doesn't mean it's correct. The steel pin will have a different hardness and wear differently than the iron valve seat. They will also have a different coefficient of thermal expansion rates, which can result in a leak between the valve and the seat surfaces. Now, you could possibly get away with pinning the crack, machining out the old seat, and installing a new seat. That's more work than simply "metal stitching", though, and not guaranteed to not drop the seat out of the head (or block). Have you measured it to determine it is indeed higher than the others? I think you may be seeing an optical illusion here. The width of the seat face may be different, but that doesn't mean it's in a different location. It being wider will have some effect on flow being different than other cylinders, but keep in mind the engine is a Flathead and you aren't building an all-out race engine. I would find it hard to believe that the machinist would grind the seat to a different depth than the others as that would directly affect the valve's installed height.
@chickenridgerods Regarding grinding the valve seats. I could find time this weekend and show you a SBC head that the shop did just that, a Quick Look over on one head show one valve not sitting as deep in the chamber as the others. No, they aren’t getting anymore work from me
I will check the height of the valves to see if this one sits proud of the others. I think it does. Thanks for you input.
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