Compression & Ignition Question

Can't do that when changing bolts. have to re size rods.

 

The rods get honed similar to the crank line in the engine block.

Material is machined from the connecting rod beam side and the rod cap so the hole is undersized.
Then the cap is installed and the rod bolts are torqued to specification.
Then the hole is honed to the correct size with no more than .0001" runout.
I see you read the thread "ARP Rod Bolt Question". Good imformation from JW

Google "connecting rod resizing" and watch some of the videos.

Pistons:

If you use these pistons again, won't they scratch the cylinder walls again?
Usually there are imbedded particles in the piston skirts from whatever damage was done the first time

We just had to replace a set of pistons because a roller lifter failed and all the cylinder walls were scratched from particles.
CP made a set of .005" over pistons so we could rehone the cylinders. We didn't want to bore the cylinders any further on this particular engine.

If these are .030 oversize pistons then you could use the .040 piston and bore and hone the walls for correct clearance.

Did you check the piston ring end gap before you installed them on the pistons?
The gap should have been .017"-.018" (.43mm to .45mm)

Let us know about all the cylinder wall measurements.

Paul

 

Definitely worth checking big end roundness, but don't assume they're out of round due to the wear pattern seen. It's quite common to see bearings designed with eccentricity, i.e. inside diameter at the parting line is larger than at 90 to the parting line. Because of this, when contaminants scratch the bearings as seen here, sometimes the damage appears to be less at the parting line.

Devon

 

Increment #1:

Torque all bolts to 30 ft/lbs in sequence​

Increment #2: ​

Torque all bolts to 55 ft/lbs in sequence

Increment #3: ​

Torque bolt #'s 1,3,5 to 110 ft/lbs, and all others to 100ft/lbs in sequence

During the next couple days we recommend re-torquing the heads three more times. First within 6-8 hours (or overnight) and once approx. 24 hours after that,
and then again in another 24 hours or as time permits.
In the torque sequence, one at a time, break the bolt/stud loose 1/8 of a turn, then re-torque it to full torque spec. with one pull.
I.E.: break #1 loose 1/8 turn then torque to 110 ft/lbs, break # 2 loose 1/8 turn and then torque to 100 ft/lbs, etc... DO NOT let the bolt/stud stop moving until it reaches full torque.​

This info is from the TA catalog​

 

I have measured the cylinders. (Up, middle and 0.5" from bottom)
I can upload the page with all numbers if is required.
The Average measure from all 8 cylinder:

Skirt-Side: 110.31mm -> 4.3429"

Pin-Side: 110.28mm -> 4.3417"

With only re-honing i will get a piston to wall clearance of 0.04", is that to much? Piston slap?

I guess the machine-shop bore to 4.317" and that was to less space for these pistons. In another thread click <--- a member means that the speed pro piston haven't enough wrist pin clearance from factory... any experience about that?

All cylinders are wided out only on the skirt side.

Then i found second mistake, i torqued the rod bolts only with the factory spec #. After re-torque i measure with the bearing inside a "out of round" from 0.03mm > 0.00118"

thanks for help and suggestions

Robert

EDIT: Exhaust Collector from 400cu 69 the same as one from a 70 455 ?

 

Robert,
You have PM.

Ron

 

Update:

After disassembling the pistons i noticed that not all pistons shake on the wrist pin without a resistance. I asked Ron about that, and he tell me that is a clearance issue from Federal Mogul. Now i very disappointed about Federal Mogul!

Now i will check the wall thickness, if they are enough thick i would like to use SRP Piston 0.38.

I tried to calculate the new CR with these pistons, correct?

regards

Robert

 

Robert

That is correct

Very nice piston choice!

Paul

 

That's really jumping to conclusions about FM being bad. The pistons should have never been installed in the engine if they were tight on the pins. It is up to the machinist to do the final pin clearance (along with cylinder wall clearance).

I've heard it way too many times on many items, on this site and in the real word, "They didn't make the part right!" But, when it came down to it the part wasn't installed correctly.

I'd say some are tight now because debris from the cylinder wall scratching has migrated its way into the pin area. It only takes a small amount to tighten up those tiny clearances.

 

Robert

Will you please polish the combustion chambers so there are no sharp edges or rough castings to cause pre-ignition.
You need to get rid of the ridges that are around the valve heads.

Here is an example from Larry's engine.

Paul

 

Robert

When you get the new pistons, and after you bore and hone, make sure ring end gap is .017" to .018" by placing the rings in the cylinder and then measuring.

Be sure to use a torque/hone plate, TA 4100R when boring and honing the cylinders.

Here is another example.

 

@Mike, now i know that Federal Mogul never do the last machine work to get the proper pin clearance. Its the work of the machine shop. We have 5-8 machine shops here in Switzerland. They know how to rebuild a old jaguar straight six, but if you want a performance engine they dont know how to build correctly. But they dont tell me that, im a electrical guy and i haven't enough experience to do that like you. This is the reason to go to a machine shop, because they know what they do. And all difficult things should they do, not me. BUT now, they know much less about buick like me...
This Forum is my last Help to complete this engine successfully.

Back to the cylinders. Im not sure, but i remember the ring gab was 0.6mm = 0.023". I will measure this and sonic check asap.
Now i want to check all clearance self.

Paul what you think about new pistons, CR?

regards

Robert

 

Robert

Those are the pistons I would have recommended the first time.
The spherical dish is a better design than the regular dish.
They have valve reliefs also

Be sure to use a torque/hone plate, TA 4100R when boring and honing the cylinders.

The compression ratio is right at 11:1 so you will need to polish the combustion chambers to decrease the chance of detonation. See post #190

If you don't have anyone to resize your connecting rods then use TA reconditioned rods, TA 1629A

Paul

 

So i was today at the machineshop.

Ring gab was 0.023" and they not bore and hone with the plate. :spank:
Paul, i cant find the TA 4100R on the TA Performance page.

 

Robert

Download this catalog to your computer

http://www.taperformance.com/PDF/TAPerformance_Catalog.pdf

The TA 4100R is on page 176

The TA 4100 is for purchace and the TA 4100R is for rent.

.023" ring gap is a little wide but still alright.
We do not want the gap tighter that .018"

Paul

 

After a bore and hone I would remove the cam bearings to fully clean as I can't see how metal debris won't get trapped behind them.Unless there is a way to seal off the lifter bores.
Jamie

 

So yesterday i received 3 boxes from TA. New rods, pistons, gasket, honeplate.....

I hope Paul and the rest of the pros are still alive to support me :Comp:

regards from switzerland

Robert

 

Robert

Good to here from you. we are all still here to help.

Very nice parts. The Crower rods will be a nice addition

Do not deck the block any further. These pistons should be .015 in the hole which will be OK.
The compression ratio will be right at 11:1

Have you done any work to the cylinder heads?

Paul

 

I will start on Monday. The heads are disassembled and all valves are polished for a better fitment in they seats.
I know i should find and eliminate all edges heels in the combustion chamber.
The piston are much lighter lighter as the speed pros, looking very nice.
Should i replace all bearings?

thanks

Robert

 

If I have an engine apart like that I always replace all te bearings, make sure to use a dial bore gauge and an outside mic to check your rod and main clearances and check thrust clearance dry once it's good remove the cap and put assembly lube on the crank surface and upper shell