Barely turns!!---Normal??

[fourbangerbob]

I have 3 connecting rods plasti-gaged to .001 and connected. I can barely turn the crankshaft! Is that normal?

[Patrick L.]

Not much info.

What about the 4th ? And how about the mains ?

Have you tried loosening all the caps slightly on all the rods and mains and see what that does ?

What has recently been done ? New rings maybe ? Has this monster been sitting for a long time ?

[fourbangerbob]

engine ran ok when I got it.---low compression 45 psi. eng sat for 40 years. no ridge in cyls---finish hone- new pistons and rings. did not touch mains. Is this normal ? may have to pull to start

[Bruce Lancaster]

Disconnect or merely loosen all caps, tighten one main at a time and rotate after each, continue on with rods until you find out where the drag is. If you find a tight journal, loosen and continue in case more than one is tight.
And of course it is possible that drag is upstairs and coming from ring or piston misfit.

[Mike V. Florida]

Well tight is normal after a rebuild but clearance of only .001 ? Are not the shims at least .005?

[Kohnke Rebabbitting]

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Originally Posted by fourbangerbob

I have 3 connecting rods plasti-gaged to .001 and connected. I can barely turn the crankshaft! Is that normal?

Your rods are set to tight, they should be set to .001-50, minimum, and .001-75 Max.

Herm.

[Dave in MN]

Many times on an engine that has some use the rod journals may not be round anymore. This condition will give a false reading with plastigage. You may actually be tighter during part of the crank revolution. The same is true of the mains but I have not seen as much of a difference in main journal roundness as I have at the rod journals. Something to consider or check if you have not placed a micrometer on the journals. Solution...loosen them a bit.
Good Day!

[Roadster Rich]

Are you turning over with the starter or by hand? I recently helped someone who had worked on his engine and trying to start, it would just barely turn. What I found was his timing was off and firing too soon. Cranking with the ignition off spun really well. We retimed and all OK.

[fourbangerbob]

Thanks for all the good advice. I think .001 is to tight and the journals are not round. I will go for .001-75 and should free up---will let you all know----

[Marco Tahtaras]

What torque setting are you using on the nuts?

[hardtimes]

Originally Posted by fourbangerbob

Thanks for all the good advice. I think .001 is to tight and the journals are not round. I will go for .001-75 and should free up---will let you all know----

Hey Bob,
Why not go with what Herm said, i.e.- .0015 ? That IS what Ford set them at , if I remember correctly.

All good thoughts given here , and the info that you gave about NO ridge ring says a lot also. The mains may have been set just right and I would not disturb those , until you find that all else is OK !

I'm wondering...did you put NEW rope seals in block and pan ? If so, you will get a lot of resistance after either or both of these are installed..which , IMO, you can understand will happen. Or is your hard turning without these seals ?

For an example, I just put a short block together ....mains/rods at .0015. ALL turned well, until I installed new rope seals at front of crank...wow, what resistance then !!

Here is a 'tip' that I got from a race engine builder. after EVERY step of assembly , turn engine over by hand twice to see what if any problem exists. Works for me..

[CarlG]

Educate me! What is .001-75?

[Joe K]

Originally Posted by Dave in MN

Many times on an engine that has some use the rod journals may not be round anymore. This condition will give a false reading with plastigage. You may actually be tighter during part of the crank revolution. The same is true of the mains but I have not seen as much of a difference in main journal roundness as I have at the rod journals. Something to consider or check if you have not placed a micrometer on the journals. Solution...loosen them a bit.
Good Day!

This EXACTLY the case on my original red Sears engine which came with the car. After some more wear, I would set the crank up so that it just "bind" as it passed the tight spot - but a push with the hand would send it past.

This an engine which had acquired the classic "whuppa-whuppa" sound when idling. And rods about 3 thou egg shaped.

I guess I used the engine until it seemed like the whuppa whuppa was just a little too much. Traveling down the Mid-Cape Highway at 55 plus (3.54 rear) suddingly the whuppa-whuppa grew EXTREME. A step change in audibility. Not thrown a rod but alarming in it's contemplation.

I nursed it home not exceeding 35. A tear down revealed that I had lost one of the rod nuts and the rod cap was being held by only one side.

"Engiine done" I thought to myself.

I found the missing nut - AND the pieces of the cotter pin - in the bottom of the oil pan - of course.

Joe K

[Joe K]

Originally Posted by CarlG

Educate me! What is .001-75?

Closer to 0.002 than 0.001.

(heh - 0.0175)

Joe K

[Kohnke Rebabbitting]

Originally Posted by CarlG

Educate me! What is .001-75?

1 and 3/4 thousandths.

Herm.

[George Miller]

Originally Posted by Joe K

Closer to 0.002 than 0.001.

(heh - 0.0175)

Joe K

0.0175 would be 17 and one half thousandth. or a little over 1/64

.00175= 1 and 3/4 thousandths. Which is what Herm said.
The rule of thumb is .001 clearnce per inch. crank dia. crank is 1=1/2
so that would be .0015 min like Herm said.

[fourbangerbob]

I was told this is a "Sears" engine!!! it was red!! I reshimmed #2 and got close to a .002 with the plasti ( at the bottom of the stroke)--tightened to 42 ft lbs---to tight!! All others loose.. AT WHAT CRANK POSITION SHOULD I ADJUST TO GET A TURNABLE CRANK?