I was reading in the S-Type section where someone said he had his V8 crank welded and recut to Jaguar green size. This is no longer necessary. Racing Green cars offers oversize bearings for both mains and rods.

http://www.racinggreencars.com/

Click parts website, find your model and click engine and ancillaries, bearings are the first thing to come up. Very popular.

 

Thanks for the info!

 

Well i got my crank machined down .25mm to match the .25mm oversize bearings and they DID NOT fit. My crank was originally 53mm and their bearings were for a 56mm crank (big end). This Left me with a large bill from my machine shop and an engine that is now useless. I cannot get any bearings from anywhere to suit it now it has been machined the .25mm. I was advised that they WILL fit before i got the crank machined and spent all the money on bearings and machineing. It turns out there are a few different sized cranks. So im now out of pocket a lot of $ and have an expensive boat anchor thanks to racing green.

 

What does a new crank run, $1,200.00 (WILD guess)?

 

any success stories?

 

The con-rod bearings of the AJ26 and AJ27 (and AJ28) were all a nominal diameter of 56mm but the later 4.2 litre not only increased the stroke but also reduced the diameter of the big end to 53 mm.

This 53mm only applied to the 4.2 litre cars and never the earlier 4 litres (there was never a running change before the newer engine-that would make no sense and would involve alot of other new components for pointless complexity at Brigend)

 

Hey Count I like your taste in cars!

Good info. It makes sense to go with smaller diameter on the con rods, that's why I'm partial to grinding them down and fitting oversize bearings.

 

when you regrind a crankshaft, you also grind away the surface hardness, leaving a very soft surface, that can score and wear easily.

not good for a performance engine,RIGHT??

when this is addressed properly, we can go into the OVERSIZE bearing thing!!

 

I honestly don't think that it's a problem. From what I've read these are cast cranks and not forged. Also, when you look at the way these motors are built the main caps are very sturdy and the block seems to have good webbing by the mains. Since all the caps are tied together that also minimizes them from walking and from excessively stressing the crank.

 

HMM, Jaguar cars actually put a nodular cast iron crankshaft in a semi performance engine!! Ah, gotta be a Ford thing.

ford does have a lot of experience in cast cranks tho!
as does GM after ford proved it worked for semi performance engines.

on that note,i have never seen a cast crank, in a German or Japanese engine(might be but havent known of one).

also OP talked about welding crank, welding cast iron can lead to small fracture cracks that once torsional twisting starts can only lead to serious cracks,AKA broken cranks,

the reason most hi-performance engines use hi-quality forged cranks. it can flex without cracking.

but on a somber note,HEY go for it ,whats the worst that could happen .

also newer techniques in welding cranks has come a long way.

so you have to ask yourself, should i spend $400-500 for a welded reman, or $800-1000 good used, or $1200. for new.

darn i hate decisens.

 

Several comments. First, I am re-doing an AJ 27 engine for Land Speed Racing. Since the engine will be turbocharged substantially and burn not only gasoline but also methanol and nitrous oxide, I have gone to GRP aluminium connecting rods and had Moldex re-do the crank. I had them cut the rod throws to the Honda nominal 1.9 that is much-used in Pro-Stock drag racing and I'm using F-M HD bearings. (And around here, last I looked, I could get a used AJ crank for less than $100.00)

KS

 

If you can find a federal mogul book you may find a bearing that will fit your crank.It takes quite a bit of time as you will have to match diameter,width and the bearing thickness(all are listed in the book).If some are available they most likely will cost less the most other bearings.

 

hi Cammerfe, sounds like it should be a great engine.

GRP rods just about the best.

i may have been ahead of the curve in 1964, i bought a MOLDEX forged steel crank new, 1/2" stroker! chevy V8. and i used forged aluminum M/T rods with offset angle serrated lower end with pins. cant remember the bearings i used prob FM, but do remember had to drill the anti-spin holes

made close to 1000hp on 30-70, Nitro and methanol. 671 blower.

i am aware that Nascar engines use a cut rod journal to Honda size , but not heard of the idea in a Jaguar.
cant see no reason it shouldnt work tho.

and good bearings should be available to fit, just gotta measure everything carefully. and keep things lubricated.

recently i have tried to use KING engine bearings, check them out , talk to people there , i'll bet they got some good ideas. online catalog.

pic of my jag V12 during build.

good luck with project,, hope for 200mph,, big boy territory! haha

 

Thanks for the good wishes. I race ECTA and, at present, hold the E/Fuel Competition Coupe/sedan national record with my '02 Lincoln LS. I'm stepping up to the blown class with a pair of turbos, expect to have in excess of 1K HP and my goal is to go 200+---in one mile.

KS