Fitting 6.0 timing chain idler assy to 5.3 block


My llatest crazy question is: Can I fit a 6.0 timing chain idler assy (EBC11024) to a 5.3 block? The reason I ask is that I will be deleting the distributor based ignition system. Looking at the parts diagram for the 6.0 (X300 model) it is not obvious from the image how the 6.0 timing chain idler assy mounts to the block or whether the 6.0 block was modified in this area from the 5.3 block, which has an auxiliary drive shaft and bushes that drives the distributor. I don’t want to order the idler assy only to find it will not fit.

(baxtor) #2

Why not simply remove distributor itself and leave jacks haft in place?


A good point. The reason for the question is that the engine is stripped down to a bare block and needs to be throughly cleaned. When I spoke to the engine guy he said there was a risk of damage to the auxiliary shaft bushes as he would have to remove them and they are no longer available, but the 6.0 idler shaft assembly is.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #4

I was unaware the tensioner for the 6.0 was different. If so, somebody needs to post some photos of it so we can discuss retrofitting it into a 5.3, as many have had their fill of the 5.3 tensioner.

I realize the last year 6.0 had no distributor, but it still must have had an idler gear where the idler shaft went; the timing chain didn’t take a shortcut across the top of the engine! I’ve long presumed some sort of idler shaft, perhaps shorter than the one that drove the distributor, was used just to hold the same idler sprocket as before.


Ah Kirbert1, it is still the same old tensioner I’m afraid. It is just the auxilary (distributor drive) drive shaft that is not fitted in the 6.0 Litre engine and an idler shaft assy instead.
I have found that SNG Barrett sell the 6.0 idler assy (EBC11024) as a kit.


(baxtor) #6

Also worth pointing out we should be more specific as some 6 litre engines had distributors and drive for same and some did not.
It’s a fair bet the pictured kit will bolt straight into the forward jack shaft bearing bore on distributor engines.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #7

I agree, looks like it’d bolt right into a distributor engine. But I think doing so might be a huge mistake! Presumably there are oil passages drilled in the block to lube the bearings all along the jackshaft in a distributor engine. Presumably those passages weren’t drilled in the non-distributor 6.0. And presumably installing the short idler shaft in a distributor block would leave those passages uncovered, dumping oil pressure. Correct?

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #8

EBC11024 sounds like a pretty late part number, does it not? Did Jaguar update the design somewhere along the line?

(Mark Eaton) #9

I “think” the front bearing was lubricated with a pressure feed via a hole in the block. But I “think” the pressurised oil was fed down the jack shaft to the rear bushes. Like the cam shafts.

Therefore the shorter jack shaft should still work.

Just my recollection. Need to confirm looking at the real thing. I have a block and 2 jack shafts on my bench, so I could report back if I remember.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #10

Who would buy that idler kit? If I had a V12 apart and was never planning on having a distributor on it again, I’d just take the old shaft out and saw it off. If I didn’t have it apart, I’d just leave the full-length jackshaft in there, it won’t hurt anything.