Single piston swap

[Quickstop [UK]]

Long story short...

Used vortec 4.3 1999 Blazer block with bad piston damage in #3 - can't afford a full rebuild so am thinking of buying a stock replacement Fed Mogul piston and swapping it in.

What do you guys think? Bearings etc will have to wait for £££. (1.6 * $. )

 

[Damian]

Re: Single piston swap

I have a stock piston with rings that have very little miles on it that I posted for sale a couple months ago. If you want it, let me know.

 

[Quickstop [UK]]

Re: Single piston swap

This is off a vortec motor so prob won't work but thank you. I may still be interested - need to check what rods are on the old pistons from the trashed block. It had TRW .030 and may have had stock rods. Could you PM me with the price and details please?

 

[midnightbluS10]

Re: Single piston swap

This is off a vortec motor so prob won't work but thank you. I may still be interested - need to check what rods are on the old pistons from the trashed block. It had TRW .030 and may have had stock rods. Could you PM me with the price and details please?

Yep. The piston he posted for sale is a stock syty piston.

http://www.syty.net/forums/showthread.php?t=90016

OEM piston, was told it might only have 20k on it when I bought it. Comes with rings and all. It is in great shape. $50 shipped.

 

[Quickstop [UK]]

Re: Single piston swap

101 views and no thoughts?

Balance?
Reusing the rings?
Willl it work?
Oil loss?

What else is there to worry about with this?

 

[s106banger]

Re: Single piston swap

i have quite a few vortec pistons, i actually scraped 6 from the last engine i had because i have so many. theyre still on the rods too, most with rings if i remember right.

i wouldnt be worried about balance for what your doing.

but i would tear down the whole engine and hone the cylinders, but im sure it would still run if you just swapped the piston and rod assemblies without doing much of anything else.

i think it depends on how far you want to take it really, but if you need a piston pm me and we'll work something out.

 

[Quickstop [UK]]

Re: Single piston swap

Thanks man, appreciate it.

The engine shop near me agreed - throwing a replacement piston in with new rings should be fine. Question is, do I take the crank out or pull the head again?

I don't want to do a full rebuild due to $$$ issues at the minute and if I'm going to hone then I may as well do that. I'll check with the shop but I'm prob going to pass on the honing and new bearings unless bearings are easy and cheap - any thoughts?

PM to follow...

 

[s106banger]

Re: Single piston swap

easiest, cheapest way. pull the head, drop the pan, and swap it out. id replace that one bearing, its cheap anyways for just one.

id be worried about getting crap in the rest of the engine when honing just the one cylinder...

 

[qbnkiller]

Re: Single piston swap

101 views and no thoughts?

Balance?
Reusing the rings?
Willl it work?
Oil loss?

What else is there to worry about with this?

Just weigh the old and new piston. Check out the rings you have. If they look fine, reuse them. Dont sweat it too much mate...you'll be fine.

 

[Damian]

Re: Single piston swap

As long as the bearings are fine on that rod, reuse them. Just make sure to put them back in the same way.

I did what you are doing on my old Mitsubishi and I was pushing 10.5psi on stock n/a internals.

 

[Quickstop [UK]]

Re: Single piston swap

Just weigh the old and new piston. Check out the rings you have. If they look fine, reuse them. Dont sweat it too much mate...you'll be fine.

Excellent - thanks Alex. :tup:

easiest, cheapest way. pull the head, drop the pan, and swap it out. id replace that one bearing, its cheap anyways for just one.

id be worried about getting crap in the rest of the engine when honing just the one cylinder...

I'm going to have to do an oil flush after all this anyway - after drilling the vortecs to match our intake and now this, I'm pretty sure there is a tonne of crap in there.

As long as the bearings are fine on that rod, reuse them. Just make sure to put them back in the same way.

I did what you are doing on my old Mitsubishi and I was pushing 10.5psi on stock n/a internals.

That's good to know.

BTW... here is the pic in case you guys didn't see it in my Syclone build thread.

There doesn't look to be any cylinder damage but the piston debris appears to have accumulated on the top of the piston and smeared off...

:dunno:

I'm going through the credit card company at the moment to carry out a chargeback. So far the engine has two cracked heads and heavy piston damage. It was sold as a running engine. :tdown:

 

[bezerk]

Re: Single piston swap

that cilinder looked scratched as ****,

 

[bezerk]

Re: Single piston swap

 

[Quickstop [UK]]

Re: Single piston swap

Hmm. So a hone is needed after all?

 

[bezerk]

Re: Single piston swap

can you actually feel the scratches?

 

[Quickstop [UK]]

Re: Single piston swap

Yeah, I think I can. The mess at the top is the remnants of the piston from detonation.

:rant: ripoff engine

:tdown:

Install - destall...

 

[Ty 1885]

Re: Single piston swap

From the looks of that cylinder, i would completely disassemble that engine, clean it and have a machine shop check everything out! If you install another piston the way it is, that thing will kill all the mosquitoes in your neighborhood!

 

[jklein68]

Re: Single piston swap

I've got a bunch of vortec parts that you can have, just cover shipping. pistons, rods, rings, etc. all used. Not sure if a hone would clean that up, especially if you can feel the grooves. Vertical grooves are really good at preventing the rings from working properly.

 

[s106banger]

Re: Single piston swap

yea, im going to have to agree with everyone else. that looks pretty bad...

 

[Quickstop [UK]]

Re: Single piston swap

So having thought about it and reading people's thoughts on here, I decided to tear the engine down.

My Dad helped me. It took me a decent amount of time to assemble but less than 10 minutes to strip with the air wrench.

#3 big end

#4 big end

This doesn't look normal/good:

The crank looks ok?? What do you think?

So we put the whole block in my Dad's car along with the heads.

I'm hoping to just replace all the bearings and possibly throw in some used pistons. Thanks for the offers guys - I'll know more when I get back from te shop tomorrow. If the scratches are no good then I guess I will bore it to .030 and try and install the TRWs from the blown motor if possible. I need two more and two rods. I don't know if I have stock rods or something else on the TRWs.

So much for a cheap motor I can throw in. :rant:

Thanks for looking, guys. What do you all think?