Changing rods and pistons engine in car

caribe94 · Dec 23, 2009

Searched and found that by jacking the engine up high enough you can remove the oil pan andd address oil pan gasket issues. But I couldn't find threads saying if you can you actually change the rods and pistons with the limited clearance? In the past I have changed rods, pistons, and rod bearings on cars with the engine in the car. Don't have a problem right now but....

Anyone done this on our cars?

Thanks

BlownFiveLiter · Dec 23, 2009

You need to rebalance the rotating assembly when you change those items, unless the new pieces weigh the same as the pieces you removed.

2002BLGT · Dec 23, 2009

pull the engine

revhead347 · Dec 23, 2009

It's doable, but it's a pain in the ass. You don't need to rebalance the rotating assembly, because pistons and rods don't rotate, the reciprocate.

Kurt

Tanus · Dec 23, 2009

be about 100 times harder like that,
dont have to balance it, but you need to bore the cylinders and add oversized pistons, do you have blow-by or rod knock?

302Feen · Dec 23, 2009

Tanus said:
be about 100 times harder like that,
dont have to balance it, but you need to bore the cylinders and add oversized pistons, do you have blow-by or rod knock?

He doesn't HAVE to bore the motor, a lot of times you can get away with just simply honing the cylinders.

There should be no reason to keep the engine in the car when you remove the internals. It will make your life much harder!

caribe94 · Dec 23, 2009

Yikes. Sorry guys. I don't have a problem right now. I was wondering if it was possible only for informational purposes. Have in the past, had to chaange a blown piston, or connecting rod bearings on cars where the engine was in the block. Had a DSM laser that had ballance shaft bearings failing causing low oil pressure. Ended up eiminating he ballance shafts, and changed the rod bearings in the car because they had overlay wipeout. Engine ran great after that. Track duty, street thrashing, and sold car to a kid that beat it up more than I ever did and all was well. I know it is better to remove the engine when overhauling it, but sometimes life's little emergencies require "unusual or unconventional" thinking. Most rod and piston sets come in match sets and don't require major ballancing unless you are looking for a max effort, high rpm application. Also, a block that has been treated well for it's lifespan usually ony requires honing to clean up the bores.
Anyway, just knowing I have access to the internals just in case I need to get to them is a relief. Sometimes I have access to a lift, sometimes I don't.
I do agree though that lifting the engine out of the car is the best way to overhaul/rebuild it.
Thankyou gentlemen for all of your inputs. Have kept this car running with help from many of you here.
God bless America

99FiveOh · Dec 23, 2009

revhead347 said:
It's doable, but it's a pain in the ass. You don't need to rebalance the rotating assembly, because pistons and rods don't rotate, the reciprocate.

Kurt

On the contrary, you do have to have them balanced as well.

Engine Balancing - Tech - How To - Terminology - Circle Track Magazine

revhead347 · Dec 23, 2009

The_Mustang said:
On the contrary, you do have to have them balanced as well.

Engine Balancing - Tech - How To - Terminology - Circle Track Magazine

No, rotating assemblies get balanced. Things like the crank shaft, flywheel, drive shaft, wheels go on a balancing machine. Pistons and rods get weighed and shaved if necessary, but there is no way to balance them.

Kurt

Tanus · Dec 24, 2009

yeah, what kurt said, they get "balanced" by making them weigh the exact same weight.

caribe94 · Dec 24, 2009

I wanted to thank the guys who responded to my question of " can you change rods and pistons with the engine still in the car?".

Want to clarify a few things as I had a problem with responses to this exact question on another site.

I believe that the problem came from my wording of the title actually so sorry about that.

If your engine needs a total rebuild, it is best to find a way to get it out of the car to do that.

The reason I asked that question was just to know how much space you could gain by jacking the engine up high enough. Since you can take the pan off, could you actually remove any one of the rod caps, and reinstall it and torque it down to specs.

There are a few scenarios where you might want to do this, and I won't even try to list them.

Ideally, it would be better to remove the engine to change the rods and pistons when overhauling or upgrading any engine to that degree but....

When I was in college in the 80's (late 80's) my roomate and I ended up changing the rods, pistons, and camshaft in the parking lot of our apartment complex at night to avoid management detection. The car ( a 1968 or so Ford Fairelane/ 390) ran very well for years after that.
Not optimal conditions, but it worked.

When reading this thread whoever you are, remember that the point to it was to provide information about if you absoluteley had to remove a rod or piston, could you do it in the car.

You can buy ballanced sets of rods and pistons, and vendors like CHP and DSS offer matched and ballanced reciprocating assemblies.

I will say this. While it's not a total waste of time changing the rods and pistons in the stock 5.0 block, the evidence seems to support the idea that the block itself is the main limitation to how much horsepowwr you can make. The factory simply did not make it strong enough.
However, that hasn't stopped guys from making in eccess of 500 whp on the stock shortblock blocks can hold up, but at those extremes if you have a mishap (lean condition, detonation) the stock short block will probably fail.

Hopefully the answers already provided will satisfy someone elses request about actual access to the engine internals with the engine still in the car and this thread won't descend into chaos like my other one did.

Love these cars by the way. And some of you have done some great things with them!!
Thanks guys

revhead347 · Dec 24, 2009

The answer is yes. The trickiest part is getting the oil pan off, which means you will probably have to pull the transmission, but it is doable.

Kurt

Changing rods and pistons engine in car

caribe94

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BlownFiveLiter

have car, will race....wait, it doesn't run

2002BLGT

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revhead347

Apparently my ex-husband made that mistake.

Tanus

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302Feen

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caribe94

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99FiveOh

revhead347

Apparently my ex-husband made that mistake.

Tanus

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caribe94

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Apparently my ex-husband made that mistake.

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