If you trust your machinist, I’d show it to him the block and the pistons as well to check the ring groove size.After starting hone but didn't finish... stone hone
If you trust your machinist, I’d show it to him the block and the pistons as well to check the ring groove size.After starting hone but didn't finish... stone hone
if you dont trust your machinist, you should find one you do trust!If you trust your machinist, I’d show it to him the block and the pistons as well to check the ring groove size.
the snap gauge and micrometer showed 3.9113 ...but the bore gauge showed, 3.906 + .006 = 3.912 just shy of 3.912
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I don't mean to highjack the op thread, but is it a good idea to have a block bored and honed with torque plate's? I'm asking because a machine shop not to far from me doesn't use torque plate's for either honing and boring
Now, I read that as the factory bore being between 3.910 and 3.912 (factory tolerance) with max .005 wear before a re-bore is necessary. That would make 3.917 the max O/S before the re-bore is required.Yup. 3.910 would be the factory unworn bore and 3.912 would be the factory maximum before you need to bore it. So, if it's 3.9113, that's still below maximum spec. Although, not by a whole lot.
I would not hesitate to run pistons with .005 clearance for what she wants to build.Now, I read that as the factory bore being between 3.910 and 3.912 (factory tolerance) with max .005 wear before a re-bore is necessary. That would make 3.917 the max O/S before the re-bore is required.
You forgot to knurl the piston skirts. Otherwise it would still be running today.Many moons ago i had one very similar to that and talked myself into a cheap cleanup with a larger then normal hone job, ring spacers on the wore out cast slugs with cut down oversized rings. That along with knurled valve guides and a cam upgrade gave me a pretty hot running engine........for about 500 miles. lol.
I surely learned my lesson on that one.
Why would you run right to +.030" when it appears the wear at the top of the bore where the top ring stops is just 0.0013"?One spot won't be enough, but if the cylinders are consistent up and down the bores then a .030 cleanup should suffice. And i would feel more comfortable with a rebuild.
Our business was the warranty depot for Western Automotive Rebuilders outta Winnipeg.
They also supplied engines for Sears, who chose us to replace the engines for them, insteada their own shops, cuz we were quick.
Talking to the owners dropping off their vehicles, I twigged on the fact a lotta these folks had done, or paid to have a re-ring, bearing shell job that didn't seem to work .
When the light bulb came on, I started collecting the 271 h/p fords, Z-28, or small journal chev, no bloody 340s however.
The new motors came without tin, -oil pans, intakes, valve covers, all that stuff had to be cleaned and transfered.
I started taking these "re-rung" home builds apart, finding broken rings, rings stuck solid in the grooves, the grooves not cleaned to their required depth, so the rings never had the space to compress into the groove, they just got pounded into the hole, rings dragging all the way, wiping out cyl walls.
Folks lined up the ring grooves all pretty, on the thrust wall, - oil rings with scrapers on one side of oil ring spacer.
Oil rings too long, butting ends on install, never mind hot.
I sincerely believe and have witnessed what a re-ring done without the slightest idea of what they were doing, and when the job was unsuccessful, well OVER FENDER OVERHAULS DONT WORK .
I knew after the first coupla mentored overhauls exactly all the things I did wrong my first times after - "I read a book".
I ended up with quite a few choice engines free after a "failed overhaul". They had all new stuff inside, just needed to be assembled properly.
I am in no way saying these daily driver overhauls are going to give racecar performance. These are daily driver cars, with regular people who own cars that required valve-grinds at 60 - 80k miles, and re-ringing at 100 - 120ish k.
This job was done millions of times across the nation, and the operation is covered in the Factory Service Manual.
Are these engines equal to a machine shop rebuilt engine, - I certainly hope not ! !
Max horsepower - big bucks, - or daily driver getting groceries, min$.
On a side note, it wasn't uncommon to get 250k miles outta a slant6 taxi, re-rung 3 times with bearing shells, and 20/50 oil .
Note for installing rings - after checking adequate ring gap on ALL rings, install the ring with the gaps at the pin -, 180 degrees apart.
(The second rings gap at one end of the wrist pin, the top rings gap at the opposite end of the wrist pin).
This puts ring gaps away from a thrust wall/surface, avoiding potential damage.
Oil ring scraper ends about 1 inch either side of the expander end, again favoring pin (low thrust)area.
Cheers.
I had warranty issues with a few WAR engines. Pull them out and send them back to be checked. Get them back stating no problems found but still knocking on a rod or main or burning oil. That is when I pulled them apart and found cranks ground 0.005" to 0.008" undersize. So the clearances were way too much. The Ford dealer had found the same problem and we decided not to use WAR rebuilt any more.Our business was the warranty depot for Western Automotive Rebuilders outta Winnipeg.
They also supplied engines for Sears, who chose us to replace the engines for them, insteada their own shops, cuz we were quick.
Talking to the owners dropping off their vehicles, I twigged on the fact a lotta these folks had done, or paid to have a re-ring, bearing shell job that didn't seem to work .
When the light bulb came on, I started collecting the 271 h/p fords, Z-28, or small journal chev, no bloody 340s however.
The new motors came without tin, -oil pans, intakes, valve covers, all that stuff had to be cleaned and transfered.
I started taking these "re-rung" home builds apart, finding broken rings, rings stuck solid in the grooves, the grooves not cleaned to their required depth, so the rings never had the space to compress into the groove, they just got pounded into the hole, rings dragging all the way, wiping out cyl walls.
Folks lined up the ring grooves all pretty, on the thrust wall, - oil rings with scrapers on one side of oil ring spacer.
Oil rings too long, butting ends on install, never mind hot.
I sincerely believe and have witnessed what a re-ring done without the slightest idea of what they were doing, and when the job was unsuccessful, well OVER FENDER OVERHAULS DONT WORK .
I knew after the first coupla mentored overhauls exactly all the things I did wrong my first times after - "I read a book".
I ended up with quite a few choice engines free after a "failed overhaul". They had all new stuff inside, just needed to be assembled properly.
I am in no way saying these daily driver overhauls are going to give racecar performance. These are daily driver cars, with regular people who own cars that required valve-grinds at 60 - 80k miles, and re-ringing at 100 - 120ish k.
This job was done millions of times across the nation, and the operation is covered in the Factory Service Manual.
Are these engines equal to a machine shop rebuilt engine, - I certainly hope not ! !
Max horsepower - big bucks, - or daily driver getting groceries, min$.
On a side note, it wasn't uncommon to get 250k miles outta a slant6 taxi, re-rung 3 times with bearing shells, and 20/50 oil .
Note for installing rings - after checking adequate ring gap on ALL rings, install the ring with the gaps at the pin -, 180 degrees apart.
(The second rings gap at one end of the wrist pin, the top rings gap at the opposite end of the wrist pin).
This puts ring gaps away from a thrust wall/surface, avoiding potential damage.
Oil ring scraper ends about 1 inch either side of the expander end, again favoring pin (low thrust)area.
Cheers.
Mainly not knowing how well the factory bore was done and if there was any taper, and because it's a 318 remaining stock, i'd personally rather do a full cleanup and get 70/100k out of it knowing that's the last rebuild i would do on that engine.Why would you run right to +.030" when it appears the wear at the top of
I had warranty issues with a few WAR engines. Pull them out and send them back to be checked. Get them back stating no problems found but still knocking on a rod or main or burning oil. That is when I pulled them apart and found cranks ground 0.005" to 0.008" undersize. So the clearances were way too much. The Ford dealer had found the same problem and we decided not to use WAR rebuilt any more.
Had problems with the engine machine shop in Yorkton also, so ended up taking dismantled engines to either Saskatoon or Regina to get machined. The Ford dealer could do valves and guides.
I do agree there are many wannabe mechanics with just enough knowledge to be dangerous. Like brake shoe leading and trailing shoes installed in the wrong positions or both leading on one side and trailing on the other.
About 45yrs ago i managed a A/C Delco warehouse in Maryland and got great prices on Target engines. I installed a few for people over a couple years without issue, but one 350 was for a show car Monte Carlo that had to be chromed out so before i installed the new oil pan i checked the rod bolts and found 3 hand tight. This was back when they were painted blue and iirc were assembled in Mexico. Needless to say i stopped promoting them and never used another.
Yikes. Glad you were there for that one. They were great engines. My bud with a Duster bought a 65' 327 Vette with 4.11's and bought a full crate LT1 and that car went 12.40's at 110 with nothing more then side pipe headers and slicks.That's nothing. One of my friends, Chuck, always wanted an LT1 engine. He saved up and bought a new short block from Chevrolet. Came with a missing upper main bearing. Luckily, I was crazy enough to check everything.
Yikes. Glad you were there for that one. They were great engines. My bud with a Duster bought a 65' 327 Vette with 4.11's and bought a full crate LT1 and that car went 12.40's at 110 with nothing more then side pipe headers and slicks.