Rotating Assy Rotating force

[buickboy]

Motor on stand. Crankshaft rotating force is fine (turns easily by hand), but when rods.pistons installed it takes a 18" breaker bar to turn over the motor. Rod bearing clearance is .0015. Chinese steel crank brand new, factory rods, forged pistons. Block align bored. All new stuff!. Looks like rod to crank and block side clearance is tight but have not checked it. Any experience or advice of what to check?

Mitch

 

[LOT]

check

rod side clearance on BOTH END--small end of rod could be rubbing side of piston---Chinese crank !!!!

 

[williambavila]

also if the rods were not resized you may have a egg shaped rod in the big end.you know the problem is not the crank mains so install one rod at a time and rotate all the way around then add another see what happens. if it spins freely with a rod then binds up your rod is most likely hitting the block or pistons.if its tough to turn all the way around then its a clearance issue with the large end of the rod. have the rods resized for sure

 

[justin84]

X2 Also sounds like there could be some bad machine work?

 

[williambavila]

Motor on stand. Crankshaft rotating force is fine (turns easily by hand), but when rods.pistons installed it takes a 18" breaker bar to turn over the motor. Rod bearing clearance is .0015. Chinese steel crank brand new, factory rods, forged pistons. Block align bored. All new stuff!. Looks like rod to crank and block side clearance is tight but have not checked it. Any experience or advice of what to check?

Mitch

you said all new stuff but it says here factory rods. they become egg shaped over time you cannot put a engine together with all new crank and pistions and not have the rods resized.. It will not last

 

[LOT]

also check

edge of rod bearing may be riding on the radius of crank--Chinese crank

 

[mikestertwo]

edge of rod bearing may be riding on the radius of crank--chinese crank

+1

 

[buickboy]

All good advice. Rods were resized by a machine shop that does lots of Turbo V-6's. Does not mean they cannot make a mistake though. Will check all suggestions. Thanks for the tips.

Mitch

 

[vkasm1]

What rod bearings are u using? That crank does not have the rolled fillets
Atleast mine didnt and I had to use the narrow rod bearings. The wide ones would drag. Something to check :wink:


Also its always going to be harder to spin when you install the pistons with rings. Normally I cant turn it by hand and would also use a 3/8 rachet and socket on the crank bolt.

 

[williambavila]

try this put one rod in at a time and rotate a complete revolution when you get the one in that makes it tough thats the one with the problem or look at a new set of rods there not much

 

[Chris Hogeland]

Take your rod caps off one at A time and look at your bearing you can tell if bearing is rubing on the radius it will leave A mark.

 

[Nick Micale]

...... but when rods.pistons installed it takes a 18" breaker bar to turn over the motor. Rod bearing clearance is.0015..............Mitch

My opinion is that your rod bearing clearance may be too tight.

This is a performance engine, not an economy V-6. Buick does list the "real" specs for turbo engines in their manual, and neither does the aftermarket.

The stock rods are rather difficult to resize, tolerances vary a lot from the hone to bolting them up. We check them 3-4 times or more during the resizing process to get them done properly.

In the hundreds of Buick V-6's we have torn down, never have seen a rod bearing or rod trashed because of being too tight unless they were set that way by the builder.

If you want a reference book, then at least use the 30 year old Buick Power Source manual which does address performance V-6 builds.

What you could try is to loosen a rod cap one at a time while turning the engine and see if it responds by taking less effort like mentioned, also have seen the bearings not chamfered for the China crank and cause this problem.

 

[buickboy]

Rod bearings are Calico coated bearings. narrow bearings which will not rub the journal chamfer. mains are the same brand. Just finished my motor with same components and no issues. This is a customers motor so I also want it right like mine. I am going to do the checking the motor again on friday so I will let everyone know. I like the chinese cranks so far. Machining tolerances are getting better with every one i work with.

Mitch

 

[buickboy]

Issue resolved

First i want to say that the Chinese cranks are getting a bad rap. Specs are right on the money. Issue was with the builder. I installed the Wiseco pistons with the P/N right side up like i did for my motor. Problem was that the machine shop installed the rods on the pistons with the cylinder numbers facing the wrong direction so when the pistons were installed the rods were 180 deg out (numbers facing in not out) causing a bind. Removed pistons checked everything and reinstalled. Rotation is sweet now. Big lesson for me and I will be talking to mach shop about how to install the pistons facing the correct way. Thanks again for all the posts trying to help. In the words of Ron White "You cannot fix stupid".

Mitch

 

[S2V6RACER]

Engine builder wasn't R.A.D was it??

 

[charlief1]

^^^ What he said please. I'm looking to do mine soon And I'm just south of you.

 

[buickboy]

Engine builder was me! Bottom line is I will be paying closer attention to the way the rods are installed in the future. Charlie f1 I will be glad to help if needed.

Mitch

 

[charlief1]

Needing machine work more than anything.

 

[buickboy]

Arlington Machine Shop does 95 percent of the Turbo V-6 work in our area. Very familiar with what is required (Journal specs, head/block surface roughness, align bore Etc.) Talk to Eddie. 817 261-9022.

Mitch

 

[LOT]

Just curious

Engine builder was me! Bottom line is I will be paying closer attention to the way the rods are installed in the future. Charlie f1 I will be glad to help if needed.

Mitch

I have heard of rods being put in backward--flipped or how ever you say it. I always though it would be next to impossible to get them in as the small end of rods would bind in the piston. Evidently not?