15 replies to this topic

[alex-95]

Due to a leaky seal I had to remove the timing cover and chain etc on my 1293, which I had to remove the cam retaining triangle plate. The below photo is what I found, Slightly excessive. I checked the end float when I was building it and was about 0.15mm (6thou) so within tolerance, I measured this without the oil pump fitted, is this correct? Other than the oil pump not being machined deep enough so therefore "clamped" the cam against the plate or the plate being too soft what else could cause this? I'm hopefully going to test the hardness of the new plate pictured against and original one tomorrow.

 

[Dusky]

Wasn't the crank end float checked on the build ?
Badly ground cam springs to mind.

[alex-95]

Wasn't the crank end float checked on the build ?
Badly ground cam springs to mind.

Guessing you mean Cam end float? If so as in the first post.

 

Ah right, will look into that.

[Spider]

The Plates do have a Bearing material plated on to them so will (and should!) test up soft on the surface.

 

Three Causes I can think of;-

 

i)     The Cam Lobes ground incorrectly (excessive Lobe Taper),

ii)    The Oil Pump seating too tightly in to the Cam. I've had one or two assemblies like this.

iii)   The Sprockets badly aligned. This can happen inadvertently as when check, you should thrust the Cam towards the Trust Plate gently with a lever.

[alex-95]

The Plates do have a Bearing material plated on to them so will (and should!) test up soft on the surface.

 

Three Causes I can think of;-

 

i)     The Cam Lobes ground incorrectly (excessive Lobe Taper),

ii)    The Oil Pump seating too tightly in to the Cam. I've had one or two assemblies like this.

iii)   The Sprockets badly aligned. This can happen inadvertently as when check, you should thrust the Cam towards the Trust Plate gently with a lever.

Cheers Chris, I'll have a look over the weekend, Pretty sure the sprockets were aligned but think I had problems getting it right.

[imack]

What cam are you using? There's been posts where people have cross drilled cams where the drilling is blanked off in the oil pump drive slot with a ball bearing that sits proud and doesn't allow cam end float.
Think it may cams ground by Kent that can be like this.

[alex-95]

What cam are you using? There's been posts where people have cross drilled cams where the drilling is blanked off in the oil pump drive slot with a ball bearing that sits proud and doesn't allow cam end float.
Think it may cams ground by Kent that can be like this.

Thanks. It's a kent 266...  Another thing to check. 

[alex-95]

I refitted the gasket, DSN cover and the triangular plate and there was no end float so the oil pump spigot, the cam slot depth or the DSN plate or gasket isn't right. At least I found what it was and will know for next time. 

[Steve220]

The DSN gasket is thicker than the OEM. I stumbled upon this during my build. Its vital to have the DSN gasket

[alex-95]

The DSN gasket is thicker than the OEM. I stumbled upon this during my build. Its vital to have the DSN gasket

Cheers mate, I remember reading that thread (This one is anyones interested http://www.theminifo...ft-pulley-shim/), I can't remember what gasket I used now but remember measuring them, Just didn't think about the pump pushing against the cam.

[alex-95]

So now I know to check the end float after I fit the oil pump, should the end float be measured without the oil pump and if it's within tolerance fit the oil pump back on and check again, then if the end floats reduced grind a bit off the oil pump so that then there would never be any pressure on the oil pump? Or just fit the oil pump and if there's end float in tolerance then leave it as it is?

[imack]

I'd check it without the pump, then fit the pump and recheck.

[Homersimpson]

Just as a thought, if this much damage has been done to the triangle plate will the end thrust have possibly damaged anything in the oil pump? Is it at lease worth removing the pump to check?

 

I may be wrong as its been years since I worked on an a-series.

[imack]

Just as a thought, if this much damage has been done to the triangle plate will the end thrust have possibly damaged anything in the oil pump? Is it at lease worth removing the pump to check?
 
I may be wrong as its been years since I worked on an a-series.

Good thought, unless it's perfect it's probably best replaced considering the relatively low cost of the pump compared with the hassle of getting to it.

[Spider]

Best to check without the Pump and again with the Pump fitted. You don't want any thrust from the Cam in to the Pump.