The average shadetree guy isn't going to be doing the machining. Just the assembly. Given properly machined parts, I don't doubt that there are folks on here capable of assembling an engine. The equipment required to do the machining is out of the reach of the home builder. So it takes the machinist to properly prepare the parts to begin with. I suspect the person who builds every week will be faster, but may not be any better than some home builders.

69 chevy. PM me your e-mail, I want to show you something.

 

And that's exactly what I said. Absolutely anyone in their home can assemble as good as a professional. It's not rocket science. What I did say was that it will be no better than what the professional can do. I don't care how much longer it takes you to do it and how many times you bath the parts, it doesn't get any better.


Some here seem to think that they posses some kind of special skill by being able to put the round pegs in the round holes. In the spectrum of the skills a good tech carries and the jobs he will perform, engine assembly ranks pretty low.

Steve g

 

Indiancreek, you've noted a few times you're a machinist. At your shop do you typically chamfer bolt holes, deburr the oil drainbacks, etc? When you do final ***'y, do you double-check the machine work to ensure it's correct? Do you check the valvetrain geometry, adjust bearing clearances to ideal, etc.?

Additionally, possibly you can share your shop's practice regarding parts going out to a home builder. Is your expectation that the builder can start final ***'y directly from the parts as they arrive from your shop with no further cleaning or checks?

Final ***'y isn't just bolting things together. Certainly anyone can assemble an engine - it's a skill, not an art - but in my experience extra care in final ***'y ensures no machining or other errors slip by and make a real difference in the final product.

Thanks!

 

Curious, how do you "adjust" bearing clearances to ideal?

Who ever mentioned putting together an engine without checking clearances? Checking clearances is part of every engine assembly whether it's a 383 sbc making 500 hp or a diesel engine in a 60 hp John Deere tractor. That's the job,it's not "extra care".

We disagree only on how many times a part needs to be disenfected before it can be used.

Experience, there's no substitute for it.

Steve g

 

It's pretty common during final checks to find a bearing clearance here or there that's a *little* on the tight or loose side. Clevite (and I assume others) make .001 +/- bearings to allow getting it right where you want it - mix the shell, and you've got an +/- .0005 adjustment.

A shop guy on the clock is going to look at the clearance, see that it's in-spec and be done.

There's always new stuff to learn

We disagree that every machine shop provides cranks, blocks, etc. clean and ready for final ***'y...and other stuff, of course.

How about starting a new thread on this stuff?

 

What he said.

I have found doing my own final assembly is the only way to verify to my own satisfaction that errors don't end up going into a build of mine. In addition, letting the machine shop(s) know I'm going to check behind them has all but eliminated finding anything wrong in the first place.

 

Show me a .011, or an .021 brg. I've never seen that, in my experience or in a parts catalogue. Pull up a part number for those.

You will find a .001, or a .002 to accommodate crankshaft wear in a case where you do not want to grind the crank. But as soon as you go to an oversize the bearing manufacturer has always made the assumption that the crank grinder knows what they're doing and supplies them only in the direct undersize.

Obviously some here reap the benefit of learning things more than others.

Steve g

 

Gen I SBC, Rod bearings (Clevite H type):
http://www.summitracing.com/parts/CLE-CB663HN11/
http://www.summitracing.com/parts/CLE-CB663HN21/

Gen I SBC, main bearings (Clevite H type):
http://www.summitracing.com/parts/CLE-MS-1038H-21/
http://www.summitracing.com/parts/CLE-MS-1038H-11/

Something we agree on 100%

Of course, learning requires an open mind, a willingness to learn and above all respect for others' experience and expertise...even when it differs from our own.

 

There are some very intelligent folks on here. I sure won't say that they can't read, research and understand the correct way to assemble a sbc. What I do see is the novice, so to speak, makes it harder than it really is.
If I make the parts the correct size and properly prepare the heads and block, there is no reason for me to believe another person can't assemble it. Some folks don't have the best tools, but I've loaned some things out before if I trust them. I always recomend a final cleaning before assembly. I allow calls if they have questions and have let some use my equipment to port a their heads or balance their rods. Things like that.
Getting involved in their engine really makes them understand and appretiate the process. Chamfer the holes, chase the threads all that little stuff is done long before it leaves.
It's my place, I own it so I can do what I want. If anyone thinks these engines were perfect when they left GM, with regard to balance and clearances, they are in for a suprize.

 

GM did some of the 0.001 and 0.002 over bearings to make oil pressures work. For example th 82 to 87 Caddy 4.1 ran very bad oil pressures. They made the #1 and #5 main in + 0.001 and + 0.002 to bring up the pressure.
Creative crank grinding would do the same thing. Buy the 0.010 over bearings and turn #1 and #5 0.008 or 0.009 giving the same effect.
Under warranty, they just replaced the entire short block.
I don't think adding a 0.001 or 0.002 to change the clearance of a worn crank isn't a great idea. As the crank doesn't wear round. So part of the journal will have a different clearance than the rest.

 

Well I stand corrected.

However, those are not intended to be mixed and matched to "tweak" the oil clearance. According to the literature they are available to accommodate polished cranks (.0.011) and situations where an additional .001 of oil clearance is desired (.009). They are to be part of an engine build design. Not a correction for sloppy work.It's one thing to know what parts are available, it's another totally different thing to know how to use them.

If you are having to use these to clean up your machine shops work I would change shops. If I get a crank back that does not meet the required oil clearance that I was expecting based on the bearings I'm using, I would send the crank back or have the rod and main bores rechecked and send them back. If I was having the crank polished to below the nominal undersize those are the bearings I would order and there should be no surprises when I check it at assembly.

I've got an open mind about learning things. That's how I got to where I am today. I think it was the main bearing radial loading wear pattern that set the stage. I learned something now and I hope you now learned how to use these items properly.

Steve g

 

Sounds like you run a great shop.

I agree that home builders spend more time than is strictly required, and typically get further into details - some of value, some not. But they're risking a lot of their own money, so they double- and triple-check things and work towards the best they can deliver.

I always tell owners that engine building is a partnership with the machine shop to be an informed consumer and work together to do a good build.

 

http://www.carcraft.com/techarticles...e/viewall.html

http://www.popularhotrodding.com/tec...rol/index.html

There are others - but it's a common build process. The good thing here is that it's not about what's "in the book" like it is for a shop rat - but what can be achieved with the tools at hand

 

Agree...anyone who expects long term endurance and reliablility out of their HIGH Performance engine builds, will clean all parts thoroughly before Final Assembly. Never get in the practice of thinking "Someone else already did that". If you don't double check the machinist's work and verify all work was machined, cleaned, clearanced and assembled to it's final form, WHO WILL? The Machinist? or the new kid in the back. Way too much casting trash and crud still found in supposedly ready to go parts or assembly's.

If you think a High Perf. engine was expensive the first time...try doing it twice! The phrase "I don't know, I didn't check it" has no place in high output perf. motors. ....Oh and Glyptal, has allways worked well for my limited oil capacity motors in the past. Very tenacous and no it won't flake off if prepped before application.

As I recall "Glyptal" is a Insulating varnish, made by GE originally for coating Electrical motor armature windings. How to "Hotrod BigBlock Chevrolets:
Was one of the first to claim it's virtues as a coating for the valley and heads. Generally Used as a coating to facillatate oil drain back. Old School, today with alloys not so much. Looks cool and in the day worked well.

Dave

 

Stay on topic gentlemen or I'll start handing out vacations from the forum.

 

The OP asked about Glyptal as a rust preventative, and I think his question has been answered as far as that goes, then the topic shifted over to whether painting the inside of the engine was a good idea or not.This Glyptal substance sounds like a pretty rugged coating, and it has been noted that it has insulative properties, also. Can anyone comment on the pros and cons of painting the bottom of an aluminum intake manifold with Glyptal? Would it be worth doing in order to insulate the intake from heat?


Scott

 

Interesting thought Scott, So now I wonder if the ceramic spheres like the type in Lizard Skin product, if mixed in with the Glyptal would even increase the insulation factor.
I'd sure hate to have it rain ceramic into my oiling system though.

 

I'd think the cost of a factory-supplied coating would be low enough such that if there was a genuine performance benefit the intake vendors would offer it for an added cost.

 

I wouldn't try it on a customers car, but I'm building something for my 75. I may try it normal, take a temp reading and pull the intake , coat it, re assemble it and get another temp reading just for the hell of it.
If I do, and there is a reasonable difference, I'll post it as a new thread. Unless I come to my senses and talk myself out of it.

 

Such experimentation is the essence of hotrodding