John Eales front pulley, oil seal run out

[PhysDoc]

Hi all,

I am building a 5L Wildcat engine for my Chimaera. I was having problems with valve gear and springs. Got that sorted now.

Just one problem after another with this build though, which I expect, but they are problems that should not occur.

Long version --

I bought a performance crank damper from John Eales. The rubber in the old damper was starting to show signs of degradation. The JE item is slightly larger than the standard item, so I had to slightly relieve the timing pointer a bit to get it to clear. It's a serp fromt cover.

I had timing marks machined on the damper, and a hole for a roll pin for the pulley.

I fitted a trigger wheel this weekend. I have had to space it off the damper a bit, so I had a spacer machined to fit between the damper and trigger wheel. The trigger wheel no longer locates on the damper in this configuration, so I had an alignment tool made that centres on the oil seal journal, and welded the trigger wheel to the spacer. Worked well.

I was measuring up to make a bracket for the sensor today, and noticed that the trigger wheel has runout, despite my alignment collar. Upon investigation...


Short version --

... it turns out that the oil seal journal on the JE damper has 17 thou of run out. Runout of the outer part of the damper is about 2 thou, so the bore is concentric with the damper, but the seal journal has been machined off centre.

My question is, how much run out on the oil seal journal is permissible? Close to half a mm seems way too much to me.

[Belle427]

Only john eales can answer this question really.
Welding not warped something has it?

[PhysDoc]

Definitely not, I only lightly tacked the trigger wheel whilst it was on the pulley so as to not melt any rubber.

[RobXjcoupe]

Did you check runout before welding to it?
Only way to correct is pop it in a 4 jaw on a lathe, clock up the centre bore and front face and see what is out and possible correct with a skim of sorts.

[PhysDoc]

No, I didn't, but I did not weld directly to the damper. I tack welded the trigger wheel to the spacer, then removed it to weld properly. I could still pick it up after tack welding without burning my hands. If I had got it hot enough to warp it whilst tacking it, the rubber would have melted too.

I can also measure the eccentricity by measuring from the ID of the bore and the oil seal journal, at 2 points 180 degrees apart. The oil seal journal has definitely been machined off centre.

Edited by PhysDoc on Monday 11th August 08:17

[PhysDoc]

I think turning it down in a lathe to correct it by 17thou will make it undersize, unless a sleeve is fitted. The problem with that I think is the keyway has been machined much deeper than it needs to be, and I think turning it down to sleeve it will break through the keyway.