8 replies to this topic

[minivan69]

Tappet fouling short of the camshaft!

MINIVAN 1098
1969
hi all i hope someone can help? I've just bought a rebuilt 1098 engine block with new bearings, pistons, etc and unleaded head from a mini parts dealer/rebuilder and on reassembly using my good parts it seems the eighth tappet is fouling just short of the cam lobe? I am only getting around 2mm of travel from the valve so the 4th cylinder won't correctly fire etc. On inspection down the tappet shaft, there seems to be some kind of obstruction which looks an awful lot like white metal? Could it be the assembler has not correctly installed the camshaft all the way? It's interfering by about 2mm into the tappet shaft?
All the other tappets are working fine it's just the one nearest the flywheel that's the problem? Also tried to tap the interfering object lightly with a shaft and rubber mallet but it won't budge?
Any help greatly appreciated. :




no non-standard parts as far as i know

[mini13]

Without looking at a block I'd say it could be a misplaced cam bearing,

cam bearings should be pulled or pressed in gentley with a mandrel, if they are "knocked" in it is likely to damage them.

[cooperrodeo]

It is not unknown for a reground camshaft to be ground down so far that the follower, overlapping the edge of the lobe, can actually ride on an unground part adjacent to the lobe. If you get what I mean.

[minivan69]

Without looking at a block I'd say it could be a misplaced cam bearing,

cam bearings should be pulled or pressed in gentley with a mandrel, if they are "knocked" in it is likely to damage them.

thanks for the reply. Yes, It certainly is starting to look that way...
I resorted to lightly tapping the object as it appeared at first to be a fragment of metal or the like?
Now It appears that it is actually the bearing edge that is interfering with the tappet.

What actually determines end float of the camshaft...only the bearing position itself? Are there shims or thrustwashers between the camshaft and bearings to adjust this?
I can't find a detailed breakdown of the bearing ends and still coming to terms with having to pull it all out and strip it down again!...gheeze!
if you want something done properly...do it yourself?

cheers and thanks again for you help.

[1984mini25]

It could be that who ever has done the work on the engine has in fact fitted 1275 camshaft bearings in a 998/1100 block. Which is a problem as the oil pump end bearing is a lot smaller on the 998’s. so sounds like it need pulling apart and the correct 998/1100 camshaft bearings fitted instead.

[cooperrodeo]

As far as I can recall, the endfloat is determined by the fixing arrangement at the timing chain end.

[minivan69]

ok. Out it comes....
cheers all.

[bmcecosse]

It's rarely necessary to fit new cam bearings anyway - only in an engine that seized up completely due to lack of oil or water! Why did you have new bearings fitted ? But well done spotting this most unusual problem.

[minivan69]

It's rarely necessary to fit new cam bearings anyway - only in an engine that seized up completely due to lack of oil or water! Why did you have new bearings fitted ? But well done spotting this most unusual problem.

I didn't do it myself...should have though!

I simply bought a supposed reco engine as mine really needed a rebore and hone and I thought It'd be better to have the 'pros' do it or buy fresh reco engine to start from a good point !??
Boy was I wrong...Shonky job.

Now I have the engine out and restripped I can verify it definitely is a wrong sized bearing as it's pushed home but overlaps the tappet tube so the tappet runs on the edge of the bearing instead of the cam. This obviously means the valve only moves whenever the highest point of the cam lobe comes round. and never properly opens.

The reco-unleaded head they sent me also has a leak from a small plugged hole they've attempted at the top back of cylinder 1...if this an unused oil pressure tube of some sort?

argghhh.
they can sort it out...or $$$ back