308 engine out major service

How much oval and taper? How much P/W clearance? Ring end gaps as removed? How much wear on the pins at the small end wear point?

Stuck choke at some time in its life, filthy air filter, running diluted oil and not changing it often enough..... Many possible answers to the wear. Answers to the above will start to point to the cause.

Dave

 

Great news. If it were mine I would straighten the bores with a Sunnen hone and have .005" O/S pistons made for it. Plan ahead for what fuel will be available in the coming years, I am dealing with the same problem right now with my white 77B. I am torn between bumping it a bit or leaving it a fairly stock rebuild that is blueprinted.

My 3rd replacement engine is on the way and I have hopes that it will have enough parts useable to build a proper engine, this one is only 6 numbers away from the original engine number. The first 2 engines were lumps that contained good parts but the heads and blocks were marginalized beyound what I wanted to deal with for this project. That said, I should have enough rods and such on the shelf that making a matching set with your good ones is a possibilty. Break out a triple beam and let me know what weights you are in need of.

Good bet if someone would only grind a few journals (who the heck would do something like that?) to .020 that the crank was never re-nitrated. Sound like you have a Bitsa engine and analizing the wear will be impossible. I would have been delighted to find what you have with any of the engines I ended up with.

Dave

 

I am in need of pistons as I have not had any made yet. I will see what the liners in the engine that is in route are like. It was sold to me as a "15K mile engine" just like the other 2 I bought. Let me know what direction you plan on going, I might have a home for the Wiseco set if I bump this engine. I have a complete shim under valve train setup and cams roughly based on the 77 specs I have been waiting to try on a street engine. Best I do it on my own car and not a customers. At this altitude I can run a good bit more CR safely.

Careful with the LM type. If they are the "slipper skirt" style Borgo's as used in the 275 era, they eat rings in short order when street driven, fantastic for race applications. Been there!

If anyone will have a Bitsa engine, it will be me. Bits of this one and bits of that one. Heck, who knows, maybe this last one will be a virgin... Right!

Dave

 

FYI WSM says need to re-nitride/harden the crank if it's had this much meat taken off it . . . hopefully you don't have to remove all the cross drill plugs if this is the case. Not real easy cleaning the crank properly with them in, but can be done.

The way it sounds like this motor was put together, doubt they did that.

When I had my crank cleaned and magnafluxed, all the crap settled in the plugged blind holes of the oil passages . . . ended up picking it all out myself with a piece of stainless wire and lots of brake cleaner instead of pulling all the plugs like someone suggested to me. Something I never worried about on every other motor I built 'cause could see right thru the oil feed holes to each rod journal (no cross drill/double oil feed like Ferrari and race cranks).

See if a bunch of grinding crap is stuck in the blind holes still or does it look like the drilling plugs have been replaced?

Sean

 

here's an idea for blowing crap outa blind holes. I've used a ball needle air fitting, the one used to put air into basketballs etc.. and with some cleaner in the hole put the needle down near the bottom and with 150psi the crap will come flying out.

 

Thanks for these pictures.

It's nice to see the guts of these engines. I've never done anything like this but at least these threads serve as a distant second to the real thing.

And now back to your regularly scheduled program...

 

I noticed your piston crown edges were contacting the cylinder walls, too much piston to wall clearance there allowing it to rock in the bore. Im assuming you arent re-using them?

 

It just so happen I have such a crank and rods for sale

 

Mine is or was a 308 QV. I'm told the 360 crank will fit and can be had starting at around $1000....but if you start down that path I think you'd be better off just buying a good runing 400 engine

 

I had a running 400, it had low compression on 2 cylinders, so it was just a core engine....clearly it would have been much easier to keep the 400 heads on it....even if I decided to move the intake ports it still would have been easier.

 

The "15K, turns over smoothly, freshen it up and go" core number 3.

You have mis-matched rods and crank journals, but have you ever seen a piston that was welded and filed flat from previous damage?

Owners wonder why some of these cars prove unreliable?! WHO would do this work??

At least this time I bought one from a friend that will get me parts to make the deal whole. Looks like I finally have a core I can build.

Dave
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Lord have mercy........

 

Not sure it's necessarily a trade off . . . if you get it clean, you get it clean. Blowing air in there would not get the crap out of the crank I cleaned . .. the drilling angles of the passages makes it where you can't get the pressure pointing straight down the blind hole . .. you also have to plug a bunch of other holes simultaneously to try and get the pressure to go where you want it 'cause cross drilling.

During an internship I remember a pro engine builder feeding a wire thru the oil passages just to double check a crank was clean . .. a piece even broke in the crank one time . . . I could feel this wanting to happen when I was cleaning out my crank 'cause it seemed like I was actually having to pick the crap out of the blind holes. A lot of debris came out of there but also could have just settled in there the way the guy had put it in the hot tank for cleaning . . . just glad I double checked it.

Great you got an extra crank and you could just have the hardness checked on the one that's undersize.

Like the idea of the 360 crank in a 308 . .. definitely not up for any V12 conversion yet

 

Yup.

Mint, one owner, virgin......... The bar has been raised!

Dave

 

What's the difference between a pipe cleaner and small brush? Our friends McMCarr have all the cleaning brushes you'd ever want . .. still won't help in the blind holes though.

As much as I like to measure and re-use parts . . . don't think I could get myself to weld a piston like that . . unless it was to settle a bet like cheapest/shoddiest 308 rebuild ever Also, with Fchat and all the forged piston replacement going on, there's plenty of good used standard pistons to be had cheap

 

Its a different time I guess. I too have a hard time coming to grips with this type of work but I am coming around to accept it these days. Imagine trying to antisipate this type of thing when putting together an estimate or game plan. It surely isnt how I was taught to service these cars.


Really rather common these days. How about a 2V head where the valve seat was welded back in while still in place so the head wouldn't have to be stripped. Vintage 12 cyl engines where a spring retainer was MIG welded to the valve stem because a keeper was lost. A rod bolt replaced with a grade 5 nut and bolt, at least the end of the bolt was peaned over to act as a saftey lock nut. Double knurled pistons in vintage 12 cylinder engines so the liners wouldn't have to be dealt with? I guess it worked in all these instances but I couldn't get myself to single knurl the pistons in my 49 Ferguson tractor with a 2800 RPM rev limit.

Are we guilty of over repairing / maintaining / restoring? Its an interesting question, whats good enough?

Twice this last year I have had lengthly conversations with very good friends / customers regarding weather the standards I use are too high. We pulled out the manuals and compared the wear limit specs with the current specs. "Its only .003" out of limit spec, thats not much". No, it sure isnt. Four grams isnt that much weight. Nope, sure isnt. Parts could have been reassembled without glass beading and treating all the mating surfaces, would anyone ever know the difference? Yup, one person would. Will it make a difference? Yes. Enough to justify the effort and labor charges? Hell, I dont know any more, where does one put the blinders on and what's good enough? In my world, Good is simply Inadequate and I can live with criticism that evolves from that.

I'm not a smart enough person to answer the question for anyone but myself. Got to give credit where its due, the above instances DID work, while Not my cup of tea. Personally I would rather be guilty of a high standard than hold my breath on the first Redline pull on a test drive. Life is just too short and for goodness sake, there ARE Ferrari's not Ferguson's!

Dave

PS, After drilling the plugs on a 12 cylinder crankshaft, it takes 4 or 5 sessions, soaking in between, with gun barrel brushes and carb cleaner before the solvent comes out clear. I have tried to clean a crank with air, pipe cleaners and solvent and then finally drilled the plugs to end up with piles of debris after using the barrel brushes. There is only one way to do it right, few do it. The last 7 engines still had the OE plugs in place and had gone through multiple rebuilds.