The V8 Owners Forum -

Hi. 94 disco, crank driven oil pump, ten bolt heads, dissy, signs of previous work ( washers under inlet manifold bolt heads, spanner marks on boltheads) had split bottom hose and faulty vac adv, hence overheated, and my cheap purchase. Appears to have tinplate head gaskets, havent pulled the heads yet, but very small gap between block and heads.
Where the engine number should be there are no markings.
My suspicion is previous work, maybe skimming the block removing the numbers, and incorrectly fitting tin head gaskets. This should have composite I believe with ten bolt heads. It would also be 3.9 not 4.0 as it has no cross bolts and hotwire?
Any ideas?

either skimmed but it takes around .040" to remove them which is a lot for a casual skim or its a new block which don't come with numbers or obviously they are removed to loose its identity. Does the block have the round bosses for the cross bolting? if not then its a old type block just with the newer front cover on. If it has them then it will be a late 3.9. If it has been skimmed that much and has tin gaskets on the newer heads you will have very high compression possibly for a gas conversion?

Thanks. It does have the bosses but not drilled. I dont think it has ever had gas. I guess I will have to get the heads off sooner to see whats up. It is going to be used for parts to complete the 4.6 block,(crank, rods and pistons) I am getting.

if its the block I think it is then your 4.6 stuff isn't going to fit without extensive machining. The 4.6 crank journal is a different size to even the late 3.9 which is what i think you have for a block.

I will use the 4.6 block, just need the front cover, sump , heads etc. Cheers.

Ah sorry missed that bit, you have nothing to worry about then really.

Engines out, drivers side head off, first, as that one had the most oil leakage. HRC 2479 heads, tinplate head gaskets, outer row of bolts barely tight.
Whoever has been in this engine obviously new nothing about what they were doing, used old style gaskets and used the torques for old style heads, no wonder it was getting hot, high compression and no advance.
The oil way at the back of the block is not drilled in this block, the tinplate gasket wasnt sealing and the oil was making its way around the gasket and pouring down the side of the block.

The outer row should really be left out completely, so having them barely tight is OK.

But it should have a composite gasket and stretch bolts for sure.

Chris.

It only has ten bolt heads, though the block is tapped for 14.
Definitely no markings on the block so will have to try to work out the compression, was thinking of putting some 14 bolt heads on with composites and an old front cover so it can be put to use again.

Comparing the pistons to a 8.13 3.5 piston the bowls are much smaller so I am guessing it would be a 9.35, so the composites with the old heads should still be workable, just as a spare for the 110 until the new 4.6 is built.

Decided to put the 3.9 block into the 110 with the auto until I get the new engine and chassis completed. Fitted the front cover from a 3.5 and thought I would need a spacer for the crank bolt but found with the pulley fitted all was good. Seems the serp pulley (damper) removed from the 3.9 is much shorter than the 3.5 damper (the amount that protrudes behind the seal), is this normal or is this perculiar to the interim engine. I was expecting the crank to be longer.

The problem that may arise is that I want to use the interim cover and damper for the 4.6.

Hello Paul,

The nose on 3.5, 3.9 and 4.2 cranks are all the same length, but the length of the keyway will vary. Later engines have a longer keyway.

The nose on the 4.0 and 4.6 cranks are longer than all of the above.

Ron.

Thanks, I guess I will need a spacer for that damper on the 4.6 crank then.
Cheers.