Rod hits camshaft

JackFish

JackFish

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Putting the engine back together and advanced the camshaft 4°.
Turned the engine over with a wrench and found number 3 and 4 rods were coming into contact with the cam and blocking rotation. :x
I just came back from trying 2° advanced and they are just barely missing each other. Too close for comfort. :cry:

So was my camshaft not properly relieved?
There flat sides that correspond to the rod rotation.
I'll post a pic if I can get a good one.
 
Is it a new cam? If so, could it have been built with advance already in it, causing the clearance issues you are experiencing?
 
No not brand new.
I bought it from Mike quite a few years ago but it's newish being in the motor.
About 3000 miles. It's the 264/274/112° Clay Smith.
They (Classic Inlines anyways) recommends the 4° advance.
 
clunk01.jpg
 
Yeah looks like you would have to grind some clearance than.
 
I was thinking about turning the cam 180° to see if the other side has the same problem.
Would that not still function normally?
I've seen some utube videos where they do that with big block chevys.
 
Nothing was done to the crank, it's stock, just polished up.
TDC looks good everything lines up OK.
I degreed the cam and it checked out as per spec.
 
I was thinking about turning the cam 180° to see if the other side has the same problem.
Would that not still function normally?
Click to expand...

No.

Are your cam timing marks right with #1 at TDC? IE #1 cam lobes for the intake and exhaust are on the base circle.
 
Jack, recheck your cam degreeing.

If degreeing in checks ok, you have 2 choices, grind the flat spots of the camshaft for clearance, or grind the big end of the rod for clearance.

If you grind the big end you will have to do all six rods & check the balance weight on all rods so thay are the same on the big end.

If you did'nt increase the stroke by offset grinding what you have is abnormal.

The X factor is the camshaft is not relieved enough on the flat spot from the grinder??

Wild guess, but are the rods installed 180" from what they should be.

Did you place the pistons in so the knoch is toward the rear of the block & did not flip the rods to there in correct position. Bill
 
wsa111":26d0sxyg said:
Jack, recheck your cam degreeing.

If degreeing in checks ok, you have 2 choices, grind the flat spots of the camshaft for clearance, or grind the big end of the rod for clearance.

If you grind the big end you will have to do all six rods & check the balance weight on all rods so thay are the same on the big end.

If you did'nt increase the stroke by offset grinding what you have is abnormal.

The X factor is the camshaft is not relieved enough on the flat spot from the grinder??

Wild guess, but are the rods installed 180" from what they should be.

Did you place the pistons in so the knoch is toward the rear of the block & did not flip the rods to there in correct position. Bill
Click to expand...
Yup I sure don't want to balance the rods.
The pistons are not reversed.
No grinding at all.
My money is on the X factor.
I'll check the rods again but are they not symmetrical?
 
Some cams are indexed for use in 1970 and later engines when used in earlier engines they must be carefully degreed in. Than there were Cams are ground to pre 1970 settings too. I wonder if you have some miss match of year parts I also think that even stock Ford 200 cams had good sized notches cast in those cam shaft areas for rod clearance should be all right.
 
Well seen your pictures just now you have the notches in the cam so the crank gear must not be set in the righ key way. Hard for me to tell here but looks like you are about 90 degrees off.
 
In the pic on #1 the lobes are facing east west, more or less, generally speaking.
Both valves are closed.
Intake has just finished closing and the exhaust will open on the next up stroke.
 
The notch of the cam needs to be lined up when the rod is on that side of the engine. Do you have a stock timing chain set to try (with single crank key way)?
 
In the pic on #1 the lobes are facing east west, more or less, generally speaking.
Both valves are closed.
Click to expand...

Is the #1 piston at top dead Center too?
 
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