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BBC Cheap fix?

2K views 12 replies 9 participants last post by  64SS427 
#1 ·
Last summer at the track my big block lost oil pressure and I pulled it out, but as of yet have not disassembled it. I'm hoping I lost a rod bearing rather than a main. Now I need to get it together for my Henry J just to prove to the better half that it will move under its own power in my lifetime.

If I have lost a rod bearing as I think, I know the crank and one rod will be damaged. I have another crank I can put in, and I'm looking at rods, but can pistons be changed from one rod to another without ruining them? These are SRP's nothing special shelf pistons which I'm pretty sure are pressed pins but I haven't looked at them for a few years. I just looked up the part number on Summit's website, 212135, and it appears they can be either pressed or floating.

So, can I press the pistons off the rods if needed without damaging them, or am I looking at pistons too?

Thanks,

Devin
 
#2 ·
Yes you can have the piston pressed off and back on on a new rod. Just make sure you use a good shop to do the work for you.
 
#3 ·
probably floating, you don't need a machine shop. stick your pinkie in the end of a wrist pin, see if you can twist it. If you can it means they're full floating. in that case you'll need to have the replacement rod honed to the correct diameter on the small end. The pistons will have pin locks visible at the ends of the wrist pins.

If you can't twist the pin and there's no pin locks visible it has pressed pins. have a shop press the piston off the old rod and on the new. IMO it's unlikely the JE/SRP pistons will be pressed on. If they are it's a little tricky to press them off since they won't have a pads on the sides for pressing.

Either way, you'll need to get the pan off to see.
 
#4 ·
Tom & Marcus are way smarter than me about this but I had that problem on a work van reman engine and it was cam bearings that were worn, had good oil pres until under normal temp and maybe a half to an hour of running in traffic then at traffic lights the pres would drop to zero, it was a ford inline 300 six from autozone, they warrantied the engine, cost me another $$$$, come to think they didn't warranty I had to deal with REMAN motors. IIRC
 
#5 ·
Last summer at the track my big block lost oil pressure and I pulled it out, but as of yet have not disassembled it. I'm hoping I lost a rod bearing rather than a main. Now I need to get it together for my Henry J just to prove to the better half that it will move under its own power in my lifetime.

If I have lost a rod bearing as I think, I know the crank and one rod will be damaged. I have another crank I can put in, and I'm looking at rods, but can pistons be changed from one rod to another without ruining them? These are SRP's nothing special shelf pistons which I'm pretty sure are pressed pins but I haven't looked at them for a few years. I just looked up the part number on Summit's website, 212135, and it appears they can be either pressed or floating.

So, can I press the pistons off the rods if needed without damaging them, or am I looking at pistons too?

Thanks,

Devin

Stock rods?
If pressed the answer is maybe
Yes they can be pressed off with the correct fixture which is one that hangs on the rod so you do not press against the piston which is a very bad idea
Assuming the proper fixture the only other issue is that the press in the rod can gall the pin & this can in turn damage the bore in the piston.
Unlikely but it is possible so I always inform people it can happen
If it is pressed send it down & I will see what I can do,,,
I rarely screw them up >:)
 
#6 ·
Thanks for the info guys, and thanks for the offer Mike. Right now the motor is residing in the engine compartment of my Henry J, but no mounts are yet built. I need to finalize that before i can pull it out and tear it down.



The rods in it are stock 3/8" with the beams polished many years ago. Being that, I suspect that they are pressed. I should upgrade to some better rods, but that means taking the chance pressing them 8 times if I reuse the pistons. But the block truly needs to be bored out anyway......

This stuff gets the ball rolling real fast!

I also have a stock 70's truck 454 I could use for the purpose. That would probably be smarter.

Devin
 
#7 · (Edited)
Would it be possible to cut the wrist pins next to rods. If that could be made happen then all you would need is new wrist pins and a set of floater rods. It may be easier to split the rod on the wrist pin and push the pin out of the piston. You may even reuse the pin, the rod should crack open before cutting into the pin allowing it to be removed easily.
 
#8 ·
Why not justif take the one rod to the machine shop and have the big end resized with the piston left on? It might put the one piston down the hole about .005 of a inch but I doubt your motor is going to notice that little bit.
if you have the bypass blocked off it could have been something as simple as a collapsed oil filter. Jim
 
#9 ·
I can get them off with no damage and no special tools or fixtures. I use some big washers cut in half to a C shape. I use those to support under the piston in a press, then heat the small end with an induction heater, a propane torch would work too. The pins pop right out with minimal pressure on the press.

To get them back in I put the pin in the freezer over night and heat the small end of the rod. They go together by hand.
 
#12 ·
SRPs are floaters. When I was a punk kid apprentice at a shop, we always rebuilt the rods, or at least checked them, when we pressed pins out. But my boss was a "blueprint nazi" on engine assembly. These days, its a simple thing on a Sunnen machine, with a minimal charge.

BTW, Wolfie's shop isnt far from you. I dont know the man only his reputation, but like the old cigarette commerical, " I'd walk ( drive ) a mile ( hours) for a Camel ( timberwolf). "

With the right jig and some thermodynamics, deflection is held to a minimum.

Have fun with that crazy Henry J !
 
#13 ·
Mike's shop is about an hour and a half drive for me. He has my "real" Henry J big block there- the bottom end at least. The heads in the pic are AFRs that need to be used for mock up of header placement before they can be pulled and sent out for some work to support the new bottom end (532 ci)

Devin
 
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