Sleeving a block & piston locations

[Brad S.]

When a person sleeves a block, and if you can reuse the pistons, do the pistons need to go back in the same cylinder that they came out???
Thanks guys.

 

[freebird01]

i would think you would give the pistons to the shop doing the work and they would bore it to match your piston. even though your boring it for a sleeve, typically the shop will need to do a clean up bore on the sleeve itself. due to the fact that pressing it in may cause it to warp and not be completely round anymore.

 

[icanfixall]

A sleeve needs to be bored to fit the piston no matter reusing or installing new pistons. That being said your used pistons must be in like new condition. Otherwise your wasting the work of boring the cylinders to fit old used pistons. Nothing worse that doing a short cut and ending up with a piston slap knock. then its to the boot kicking your own butt award pole.. If you doing all this work why short cut things. I can understand if the pistons are in great condition but not seeing them or measuring them my thoughts are go new or go home. Its very difficult to see thru the computer to what a member is telling us. but words will help us to understand. Please use more of them...

 

[Brad S.]

Your right Gary about the pics, they will soon be coming. Last night I was tearing down the motor, had the oil pan off and looking "up"/down at the bottoms of the pistons etc.
For a engine that is mostly a daily driver, is there real big advantage to balancing.???
(part of the reason for the question, the bottoms of the rod=rod cap, looks much shiner that rest of the rod, will have a pic of that too.)
Normally I would equate balancing with a engine that spends a lot of time in a higher rpm range.

 

[icanfixall]

Balancing an engine increase the useable hp at the crank. Line boring the main webs to straighten them increases hp to because the drag has been reduced. Look at the mains when you remove the caps. You probably will see some heavy wear thru to the copper on one edge or the other. That bearing is not square with the crank bearing so it drags and wears off the edge. Now look at the rod bearings. If the same thing is seen there like it probably is then that tells you the cylinders are not bored square to the crank. They lean towards the front or back of the block causing a wear pattern like that on the edge of the bearing. So deck the block. Line bore the mains and line bore the cylinders to the crank. Most every V8 engine block has a slight twist from front to back. The measurement from the top of the block to the center line of the crank is 11.137 to 11.141. Thats 4 thousands. Not much can be removed and still be withing factory tollerances. Remember decking the top of the block changes the crank to cam gear spacing. Probably less than 1/2 thousands differance is done to the crank when the main webs are tured up because usually the shop cuts 2 thousands off the main caps. then they torque them to the block and machine out the bor openings to the bearings. So not much if any movement of the crank is done upwards in the block. The most difficult problem with the 11.137 measurement is finding it. One can't just drop in a depth gauge and get it. You need a dummy crank that straight with no rod bearing throws plus the location where the rods belong has to be the same size as the crank bearing journals. Then you measure down to that shaft. Then you have to subtract half the diameter of the shaft to find the center of it. Lots of work when most shops will bolt it in a fixture and take a cut to true it up and tell you yeah... Its straight now. We had to take a little bit off but its ok.. Ask them to prove what they took off and you will get the dumb look and asked to leave or be thrown out. Some shop machinists don't like being asked questions like that. Those are the ones you want working on other peoples engines...

 

[riotwarrior]

Multiple issues...

A rod bearing showing a SHINY spot on the bearing is usually an indication of OUT OF ROUND rod cap.

Having TRUE square, and round holes and all weights equal is good for any engine regardless of RPM you want to run the engine at. It all equates to less wear and tear and more freed up HP/TQ due to less internal friction and cylinders making an equal and balanced amount of power.

Thus, boring and then sleeving and utilizing old pistons and pins does not equate to a quality build sorry to say.

Just sayin...

Al

 

[Brad S.]

Wow lots of good info, thanks.
I'll be sure to get some pics of the mains & rod bearings.
Not trying to generalize to much but, could cylinders 1 & 2, 7 & 8 be the ones to watch for uneven wear on bearings.
I'll watch all the bearings.
Not that I want to do this can we (IDI owners) offset grind crank to pull the piston down in the bore to gain some cubic inches..??? or does that weaken the crank too much.

 

[icanfixall]

A machine shop on the east coast called Barnett Proformance has 2 stroker cranks for our idi. They have a fine web site too. So the answer is yes. Now Mahle who is the oem piston supplier for our engines has a low compression piston. It drops the hieght of the piston 10 thousands in the cylinder by machining the pin location 10 thousands higher up in the piston. So it drops the piston by that much. I have never heard or seen a piston thats lowered the pin location in the piston to increase the stroke. That would raise the piston that much more out of the block. As it is we have pistons coming up out of the block by as much as 30 thousands already. The only reason we don't have a piston to head contact is the thickness of the head gasket keeps that from happening. Our heads are flat. So figure a gasket compressed thickness of say 70 thou and a piston up 31 thou.. you see the clearance is 40 thou.. Not much but a miss is as good as a mile...

 

[Brad S.]

Ok get your pics hot off the digital presses.

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rear main cap with bearing

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Crank 7&8 throw

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Rear main crank journal

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Rod caps 8 on top & 7 on bottom
Ok this is all I could get off tonight, something about the better half being home and wanting to spend time together. meh
Just a couple of info bits, I've had this pickup for about 11yrs and I put about 125k miles on it, it has 267k total.
The crank journals have no scratches or grooves.
Didn't have time to get these two pistons out cause of ridge in the cylinders.
Tell me what you think.

 

[icanfixall]

Those mains are showing some edge wear so I sure would have at least line honing the main bearing webs. That takes off less material than line boring the main webs. The rods look ok in the pics. Probably have true cylinders to the crank so little if any edge wear.

 

[Brad S.]

Thanks Gary, I'm really curious about the rings so I'll be getting to those quickly.
The black RTV around the oil pan almost makes me think someone did a bearing replacement. It just doesn't look factory.

 

[Knuckledragger]

Installing used pistons is asking for problems. not only from exterior wear, but because the ring lands are already worn. A new set is about $250 on fleabay.

The cost of balancing an engine is worth it ($200-$300 should do it). If they only work on the pistons and rods, you aren't getting a balance; you need the flywheel, crank and harmonic balancer checked and dealt with as well.

 

[icanfixall]

Proper balancing is everything that rotates. Main bearings don't rotate hopefully but rods do. So if it spins its part of any balance shot. Even our cam gears are balanced better now.

 

[riotwarrior]

Well after a really thorough look at your pictures I've got some observations and I could be wrong cause the glare may be causing me to see things that are not.

two rod caps picture, that upper cap in that picture, can you confirm to me if that is the rod on the RIGHT SIDE of journal? the lower rod is LEFT side of the pair? I'm guessing but I have suspicions based on the marks in the bearings and on the crank.

It appears the bearing on the upper cap in picture is starting to fail and is wearing through to the copper layer.

Again this is just an educated WAG if such a thing exists. Suppose that's like Microsoft works or jumbo shrimp...an oxymoron?

I won't say for certain however my suspicion is that at some point some bit of crud was picked up and passed through the oiling system, or the filter's bypass opened up and allowed some unfiltered oil to pass through system.

The other thing it could be was a burr on the cranks oil journal and may need some light champhering, again with no real good image of that spot yet, it's supposition.

Crank looks ok and likely will get by with a good micro polish, I'd not be grinding it as it has a hardened surface. Look for a replacement crank if fault is found that warrants it.

Main cap could have been machined just off square by looks of things as Gary mentioned align hone would be nice.

Again untill the whole enchilada is there to see it's difficult to say. Doing things right the first time when this deep in can mean the difference between 10000 mile ??? engine and 200K+ engine!

Keep the pics coming and we will surely keep the commentary up too.

JM2CW take what ya want...leave the rest.

Al

 

[Nrliftedranger]

how much do these stroker cransk cost?? i couldnt find them