The 'E' Type Forum

Morning all,

I am currently looking for a series 1 or 1.5.

I know that at some point the engines on the later used long studs, and that this can usually be determined by the fluted cam covers as opposed to the shiner ones.

Can anyone point me in the direction of an engine number cut off? I have looked at SNG’s website but the parts list foe series 1.5 shows only short studs, but I was under the impression that series 1.5 phased in long stud engines around 1968?

Anyone know the definitive answer please!

Steve.

Parts catalogue gives the engine number cut off numbers...easy way is look at the block core plugs.....oil filter side.....5 for long stud 3 for short.....Steve

Out of interest (yes, I’ve tried searching) why were the long head studs introduced? They seem to be disliked but must have been fitted for a reason. Perhaps to save a couple of pennies on the cost of building the engine
I’m sure Heuer will know the answer, please

Geoff

Geoff...you arnt very good at this searching lark https://forums.jag-lovers.com/t/long-st ... ock/367849

I thought all the answers regarding E Types and their engines would be on the E Type Forum. Therefore I didn’t realise I would have to extend my search to a website on the other side of the pond

I also question a comment in the linked AJ6 Engineering page where they question the RR Merlin. Saying it was plagued with problems and needed an enormous amount of development. That development was due to the ever increasing demands of wartime where an engine originally aimed at 1000 hp with a single speed single stage supercharger of +6 lbs boost ended up with over twice that power (up to 2500 hp) with two speed two stage blowers giving +25 lbs boost and even up to +30 lbs. Without increasing the capacity. That was why development was needed.

mgcjag wrote: ↑

Thu Dec 04, 2025 6:40 pm

Geoff...you arnt very good at this searching lark https://forums.jag-lovers.com/t/long-st ... ock/367849

Thanks for posting this link. I read this previously, and having worked on these as an apprentice can confirm the reasons as correct. Basically they had some issues with gaskets, so in order to increase the clamping force dropped the studs into the block (Shame it didn’t work on the late MGF 1.8 motor!). The problem occurred when the cars got older and people either let the coolant concentrate get low or in most cases ran them on neat water. This caused the studs to corrode and in some cases snap off. The cast iron blocks used to suffer with what we used to call ‘Shailing’. The neat water would cause surface corrosion which would flake off leaving a sort of ‘shail’ in the lowest part of the coolant jacket, I.e where the stud screws into the block. The water pump didn’t help as it was a really old design, not really moving coolant around like a modern one would. I used to abandon the idea of getting the old stud piece out of the bottom of the block if they snapped as when the stud was fitted it had a chamfered plain section on the bottom to help it seat in the block, effectively meaning once it was in and tight, if it snapped it was never coming out…

We used to drill the top of the block and tap out & fit a helicoil which would take a shorter, earlier stud. Never had an issue with them after that plus you could fit the existing nut as well.

What this link doesn’t tell me is when the cut off point was, I.e engine number change over point? I don’t want to buy a long stud motor due to the nightmares I had back in the day, and as a series 1.5 may now be in my sights, I need to know this.

I’ll call SNG today and if I can obtain a definite answer I’ll post it on here.

Thanks all

Steve.

I posted the answer above.....if you dont have a Jaguar parts catalogue then look at the ones in the Knowledge base section......Steve