Rebuilding an early GT6 Mk1 Engine

[Mike Lester]

Hi guys,

 

I'm no stranger to rebuilding engines from the ground up, I've done several 105 series Alfa Nord blocks, but never a Triumph block. They look relatively simple. As it's a Mk1 block I'm not going crazy with the rebuild, no hot cams needed, it's just a road car and will never be raced. Main reason for rebuild is it leaks from literally every gasket and compression is very poor, piston rings are dying in slow but spectacular fashion.

 

I did consider the TSSC engine rebuild service after speaking to Garth at the AGM but considering the high cost and the fact I can do this myself (I would just be being lazy if I opted for it) I have put this option aside.

 

So I was going to just buy an off the shelf kit but I noticed all the ones for sale (Rimmers etc) are listed as "Mk1 Late > KC5000", but mine is an early engine with number KC4034F. Is there such a vast difference that the later kit won't fit? I only need a short block kit, not the full engine one, as the head already has unleaded inserts and has been de-coked recently so doesn't require attention, the valves are all lapped in and in perfectly good condition. I already know about the recessed and non-recessed block differences, but didn't know the later Mk1 blocks were any different to the earlier ones. Are they?

 

The car itself is a bit of a mish-mash thanks to a previous owner. It has a later gearbox and overdrive, for example, likely off a much later model. Those will also be pulled for a rebuild as currently choosing a gear is like stirring pudding with bits of rocks in it.

 

 

[Clive]

I would have a look at teh engine once apart, as you know many will benefit from just a hone and rings, and even just a bearing replacement.

 

Be careful about suppliers too, buy th ebest bearings you can, often the county hd (trimetal), but they should be better than their std offerings. Payen gaskets where available and so on. 

Chris witor may be able to help, as can canleys and no doubt james paddock. 

 

As to gear change, that will be a simple remote rebuild kit, about a tenner and an hour at most.

[thescrapman]

The early engines used the Vit 1600 bottom end.

 

This is good!

 

You can still buy Vanvervell VP2 bearings for the bottom end.

 

The engine is much "sweeter" and revs more freely.

 

So check your crankshaft dimensions.

 

Cheers

[Pete Lewis]

there are two diameter cam followers early small and late   bigger 

 

with the head nuts get some  deep HD ones from canley and hard washers the small 3/8 studs take 46lbft and any weeny nut will strip and washer deformation will add to loosing  torque/clamp

 

upside down wheel nuts make a good  cheap  everlasting job , but they are too big  by the pedestals

Pete

[Mike Lester]

Cheers guys, I'll favourite this thread and go through it once I have the engine all apart.

 

I'll know more what to get once I have it apart and can see what it already has. I have no idea what the previous owners did to it, if anything. I highly suspect it's never been rebuilt and ragged everywhere.

[Darren Groves]

If you want engine parts, take a look here: http://gbhspares.co.uk/Start00.html he's worth a call, he has huge stocks of NOS parts and only sells quality items, no rubbish.

[Mike Lester]

Cheers Darren, that looks like an extremely valuable resource, I didn't know about that guy before.

 

The only other thing I'm having trouble with is getting the Mk1 head to be oil tight on the pushrod tubes. On this engine they're removable and I had to get most of them replaced at great cost as they were crushed and generally in very bad condition. The problem is that they leak as if they weren't there at all, I understand this is oil squeezing through the gaps at the top and bottom when under pressure while the engine is running, and I have been told they can be sealed using an appropriate compound.

 

But no one can tell me what the best thing to use to seal them is. Something that needs to withstand both oil penetration and the heat of a running engine, obviously.

[Pete Lewis]

back in the days of production and solving oil leaks we used Loctite 574  

 

this solved everything joint or sleeve faced  conditions once and for all,  thats after years of testing every other setting non setting 

 

this goes off when air is not present and makes a very permanent  leak free joint

 

Pete 

[Dick Twitchen]

Mike, 

Echo what all the above have said.  When I rebuilt my early mk1 engine I took it one step at a time but sourcing decent replacement parts was the biggest issue; in the end I avoided R......... and stuck with either suppliers of NOS or those who actually do work themselves.  Clive's comment is particularly perinent; I was already psyched up for a re-bore but on dismantling a hone and some over size rings from Jigsaw (preferred supplier even if slightly more expensive) was sufficient along with a re-grind on the crank (same source of bearings and advice).

Dick

ps Loctite 574 cured my leaks!