My wonderful TR7 has blown it's head gasket so I was of the mind to replace it myself. I know the head will need skimming in case it has warped.
But, before I get to that stage, has anyone any tips for the job in hand, be it preparation for dismantling or tips for re-assembly ?
I have a Haynes manual but as we know, some of those "Simply remove the...." phrases can turn into 2 hour tasks and lots of scraped knuckles.
Advice (other than "the scrapper will give you £30 for it") much appreciated,
Regards,
Stu
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Seems the ideal time to think about finding a 16v head at the same time.
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I did one years ago and I remember it's not the easiest of jobs. The camshaft is chain driven and I recall having to remove the front cover to retrieve the chain which dropped, or they used a spring loaded tensioner which fell apart. Something like that.
Must've been more than 20 years ago now....
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I have done it on a Dolomite Sprint though it was 20 years plus ago, I recall having trouble getting the waterpump out which I wanted to change at the same time while the inlet manifild was off, although the Sprint is 16v it only has one cam sprocket because one set of valves are actuated via rockers so while the head is bigger it is a similar job to the 1850 or TR7.
As has been said why not get a Sprint head or a Sprint engine, add a pair of 45 DCOE's and you are really flying.
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I clearly remember holding off buying my first SAAB until this Coventry engine was replaced by their own (reliable) version of it.
Having worked on a few, there are some wrinkles, but the most dire feature is that one row of cylinder head studs is inclined at an angle to the axis of the bores, and the other row is parallel to this axis. The consequence of this is that the angled studs have to be unscrewed and removed completely before the head can be lifted, which is why there is a visible screwdriver slot in the ends of these studs. (All of the studs are external to the cam cover).
Do not underestmate the difficulty of removing these studs in an old engine. Bi-metallic corrosion sets in, making these almost impossible to shift, and many heads have to be cut free. The screwdriver slot is a real joke! Of course, the uneven clamping force provided by these angled studs makes gasket failure more likely in the first place.
The timing drive on this engine is a simplex chain which drives the oil pump via the jackshaft. It is not up to the job, especially considering the poor sprocket angle wrap of the chain on the crank sprocket of this configuration, and wears rapidly - replace all parts. In fact, there is a very neat bracket arrangement built into the engine to take the top sprocket whilst the head is removed - copied by SAAB. SAAB used a trouble free duplex chain in their version.
Water pumps (gear driven) are also a problem as you need a tool to hold the impellor whilst you unscrew the (LH thread) retaining nut. If you don't do this, the gears strip. You then need a puller or a slide hammer to get the pump out of the block. The bearing/seal assembly is complex with lots of O rings - you need new ones all round.
I don't want to be a prophet of doom, but this was one of the poorest engine designs to come out of Coventry. I've worked on a few in the past, so can assist with advice as necessary. Go very carefully, don't bodge and trat the cooling system very carefully indeed when you have finished.
659.
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Oh dear :-(
So it's going to be a lot more difficult & troublesome than the last 2 cyl heads I replaced on a Montego and on an A-series before that then (I haven't done one for about 6 or 7 years).
It's had some top end work done about 5 years ago so maybe the studs won't have seized solid in the block, maybe just very tightly.
The AA guy who came out to it had worked on a few before and he said they were known for head gasket failure.
Thanks very much for the advice. I shall ponder the consequences of all your comments.
I don't think I'll be fitting a Sprint head just yet however. The car has seen a number of bodges performed by the previous 18 recorded owners which would require attention prior to any such upgrade.
Thanks again,
Stu
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>>It's had some top end work done about 5 years ago so maybe the studs won't have seized solid in the block, maybe just very tightly.
If you are lucky, the void between the tilted studs and the head will have been packed with grease to prevent/reduce the corrosion of which 659 speaks when the head was last off.
If not, good luck!
Number_Cruncher
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You can't make a 16V engine just by fitting a sprint head, the pistons & a heap of other bits are different, generally cheaper to find a sprint lump. But it deffo needs upgraded brakes if you go down that route.
99% sure that both Sprint & 7 have single row chains, generally the chains are not a problem anyway.
Yup if the head has been off recently then you maybe OK but getting the angled studs out an be a complete PITA!
If the head gaskets blown their is probably a reason eg. a clogged rad or knackered water pump.
Worth considering an exchange head from Robsport or S & S as its completely recon & all shimmed up, can be a lot quicker than doing it piecemeal.
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The single row chains were underspecified for the job and gave a lot of trouble on the early SAAB 99s which used this engine, initially as a 1709cc unit.
This engine was so grief-stricken in other areas that the timing chain problem probably never fully emerged in the Triumph applications. In the SAAB, the cooling system was rather better designed, with the result that head gaskets tended to last (a little) longer so rattling chains were relatively commonplace.
659.
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The timing drive on this engine is a simplex chain>>
Are you sure, IIRC the Sprint was duplex.
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The Sprint engine was duplex, but the 8v engine wasn't.
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