line boring delima

[larry harding]

i am build an engine for my speedster project. after waiting and searching for months i have the main inserts. a friend has a line boring outfit, but has only done modern v8s not an a block. another friend has done several a blocks over the years, but doesn't see very well. we have spent several hours this week with me doing the grunt work, but only helped on another line boring job a few years ago. we have now removed most of the babbit, but i'm a bit uncomfortable with the way things are going and don't want to chance ruining my block. Is there anyone around western n.c. or east tenn. that can do the line boring right? there is a guy not far away, but he only does babbit. he wont bore for inserts. suggestions please.

[Fullraceflathead]

There's 2 critical dimensions the actual diameter for proper bearing crush and also the distance from the cam shaft to the crankshaft center line both of those dimensions are critical. You probably already know this.

[Fullraceflathead]

A person that is good at doing line boring on a regular V8 engine should be more than capable of doing the model A. as long as they are aware of the distance from the camshaft center line to the crankshaft center line.

[ThirstyThirty]

certainly an engine building procedure that must be done correctly! my '32 B engine has fresh new babbit bearings. once installed into the block and caps... the engine shop line bored it on original FOMOCO tooling/rig... and the operator was an old gent who did that very job on that exact tooling for FOMOCO back the the early days! I found the engine whilst up in CO on a ski trip. cook's tour of shop and saw their line boring set up. another engine was being readied....

like honing a cyl... often best final fit bore/piston is done by an operator that is also a machinist or has that background. if your situation was mine, i would begin calling as many engine shops as i could find and would be willing to travel to wherever it might be located, hopefully close or within ur state.

for me, i have honed more than just a couple of engines... 600 grit and gasoline... reline bored engine with crank and rod bearing brass shim stock (.007) with excellent results! ... and while never had to... always heard some bacon rinds well placed could get a Model A a few more miles!

i goggled babitt bearing services for NC. there were a handful of links that came up.

good luck with your engine building project.

[nkaminar]

You might try these people in Taylorsville. They do not advertise work on Model A's but they have worked on them.

https://www.harringtonsmachineshop.com/

[BRENT in 10-uh-C]

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Larry, I am no longer doing insert conversions due to the failures we have seen. The only experienced machinist that I would recommend in NC would be Randall Strickland over near Mt Airy. Otherwise, my recommendation is have the block poured by James over near you.

[Richard Knight]

My suggestion is to find someone with a Tobin arp TA-14 or 15 AND the alignment fixtures made by Tobin arp that centers the line bore in the block and gives you the correct distance between crank and cam centerline. There may be other fixtures and nothing bars but I am most familiar with Tobin arp. The Kwik way fixtures also establish these centerlines but I only used the Kwik way for Babbitt. The Tobin arp is made to bore blocks. Often modern shops who "bore" main bearings are actually align honing the bores and not actually boring. This is not a job for a beginner!

[ModelA29]

Dan McEachern makes gears to compensate in case you don't get the crank/cam distance just right.

[larry harding]

after chasing the bearings all winter, i am determined to go with them. i thought the guy with the body shop was going to do the job for me, but mostly he is letting me use his shop equipment and offering advise. i am only a backyard amatur machinest and don't trust myself on the critical part. the other guy is older and had experience but with failing eyesight things are scary.
we have remover most of the babbit so now hings get really critical. ithink i am willing to pay a pro to do it up right. we are working with a quickway boring bar and i'm turning the bar by hand rather than using a motor.

[nkaminar]

Larry, Give the people in Post #5 a call. Please let me know what they say because I have considered them for other Model A machining jobs.

[Gene F]

Originally Posted by BRENT in 10-uh-C

Larry, I am no longer doing insert conversions due to the failures we have seen. The only experienced machinist that I would recommend in NC would be Randall Strickland over near Mt Airy. Otherwise, my recommendation is have the block poured by James over near you.

Brent, if a fresh engine has inserts, about how long is life expectancy? If babbit (not diesel babbit) how long? Just an educated guess is fine. Let's assume the center main gets the little pressurized tube in each case, with a 30 lbs flywheel.

[nkaminar]

Here is a little graph that shows the bearing life as a function of the Babbitt thickness:

[BRENT in 10-uh-C]

Originally Posted by Gene F

Brent, if a fresh engine has inserts, about how long is life expectancy? If babbit (not diesel babbit) how long? Just an educated guess is fine. Let's assume the center main gets the little pressurized tube in each case, with a 30 lbs flywheel.

Answer my question first as I feel the answers might be similar. My question is; "If you & I were going fishing, how long will it take for us to catch a fish??"

[Gene F]

ok I see your point

[rich40701]

If it is not too far you could try Knoxville Rod & Bearing Co, it is located at 915 Cherry At I-40, Knoxville TN, 37917
Many years ago they babbitted new bearings for a T-model engine for a Speedster that I helped my neighbor with and they did an excellent job. I know they have been in business for over 40 years.

http://www.usa.com/frs/knoxville-rod-bearing-co.html

[History]

Randall Strickland did my inserts and I’m very happy with the results. He’s a member also of this forum.

[BButturff]

Originally Posted by BRENT in 10-uh-C

Larry, I am no longer doing insert conversions due to the failures we have seen. The only experienced machinist that I would recommend in NC would be Randall Strickland over near Mt Airy. Otherwise, my recommendation is have the block poured by James over near you.

I will 2nd the recommendation for Randall Strickland.

[Richard Knight]

Do you have the Kwik way alignment fixtures? Do you have carbide cutters to cut the iron and steel, how many towers are you using. Why aren't you using the power feed? The feed can be adjusted to .002 per revolution, that is a lot of hand cranking.

[Dan McEachern]

If you don't have the ability to bore the saddles to within .0005" and measure them to the same accuracy, you are probably better off sending the job to someone who can. Without being able to do that, you will not be pleased with the result. You don't need carbide cutters, but you do need to have reasonable skills to do the job properly. A babbit job is much more forgiving compared to inserts. Just my opinion. Randall does seem to know what he is doing, not to say others don't but...........

[larry harding]

the guy who is letting me use his equipment doesn't like power feed because you can't feel any kind of snag as with hand feeding and if you break one of carbide tipped cutters that is $100.00 gone and i understand these cutters are hard to find. my older friend insists we continue monday and see how things go. i'm in so far now, i guess we will keep going i just wish i had known how this would go, i probably would have farmed out the work and saved a lot of headaches, and maybe my block.