I spent the better part of yesterday in battle with a rounded off upper starter bolt that a previous owner left as a fun surprise. As the restoration has progressed I've found that the biggest headaches always arise from previous bodge jobs and not from anything inherent in the car's design.

Case in Point:




Based on the evidence (rounded off upper bolt, original starter dated 21/86, tool marks on the starter flange), it would appear someone got frustrated and tried to pry the starter out, cracking the engine block in the process.

The engine is about to come out to be stripped and rebuilt. Does this look like it can be welded? Looking closely the starter flange has dropped a fraction of a millimeter around the crack. Or is it time to start looking for a donor engine block?

Not a fun day in the garage.

 

It could be welded, but if the engine is coming out to be rebuilt anyway, it might be better to find a good running engine and drop that in.

I suspect that wouldn't be an easy thing to weld, you'd need to find a skilled aluminum welder.

 

I got one! Sad part is I'm half way across the country from you. LOL! I'm in Northeast Arkansas, by the boot heal of Missouri. Cali is about 2000 or so miles from me. So it's not just across the street. Good Luck. As stated it can be fixed, but that is one of the most highly stressed areas of an engine block due to the torque required to start the engine. Ask any Chevy lover about breaking the flange off at the starter. they will tell you it's a nightmare and very few of them ever stay fixed for very long. Just some food for thought. Hope it helps.

Jack

 

I had very similar crack on my series 1 xj12 probably 40 years ago.
As with you it was discovered prior to rebuild so l used a replacement block. Not worth welding unless replacement is not possible.

 

Thanks for the input, I suspected as much.

There's a 1988 parts car (So Lucas Ign) for sale near me, that engine block should be identical right? I'd still be rebuilding it and I'd have the benefit of using the best internals between the two.

As distressing as this discovery was initially, I guess I'll finally get to make that V12 coffee table I've always wanted :-)

 

Identical block.

 

For what irs worth, that's an easy welding repair for any decent tig guy.

 

Due to my many limits I rarely weigh in on situations like this. But help me understand...

Are you saying that you intend to scrap this entire engine block for THAT crack? Has this engine ever been spun over with a starter bolted into that block with that crack? 1x,,, 1000x? How many times?

If 1000x and it's been this way for years, and the crack is showing NO signs of widening or deforming is it really the judgement and idea that the whole engine be written off and scraped... I think that's nuts.

I hate waste. Especially waste of beauty, craft, skilled engineering, all the heat, materials and tooling that goes into every bit of an automobile... It's one of the reason that I took the 4 cars I have. They were all going to the crusher and needed to be rescued... All driving today, all good.

Weld the crack and (literally) keep it moving.

 

I understand where you're coming from, but welding thick aluminum isn't as easy as thin material. Generally the parent metal has to be clean, and any oil impregnated into the metal will seriously compromise weld strength. Cleaning that piece to the standards required to return the parent metal to it's original strength is very difficult. Then I would be concerned about warpage, as it is very easy to warp metal from the heat input of welding. The surface will have to be machined back to flat no matter what, as the weld bead will always be proud of the joint

It's starts to become a balance, as this is a specialist welding job for a skilled TIG welder, and it will be an expensive job. I expect it's actually much cheaper to simply replace the block. There are lots of specialist welders in the part of the world I'm in who could do that job - for $1500-$2000. Could it be done? Yes. Does it make much sense? No.

 

I'm not a welder. I've watched some folks weld all sorts of high stress aluminum and what they seem to be doing is opening the material up creati g more surface and just welding it, then cleaning and reshaping the part being welded... If someone tried to charge me 1700$ for this I'd hit em in the snozzzzzle. But that's me. NYC must be affecting me, lol...

How long has the crack been there ya think,,,? And how many times do you guess the starter was run with the crack as is? Just wondering

 

I’m of the opinion that it is easily weldable as well. as already said that crack does not seem to have propagated and a good welder could lay a bead on the outside that would tack it together to give you additional support. Flatness not necessarily critical at that point. you just want to have the starter flange sit flush. I would definitely try to weld it And no way with anybody charge you anywhere close to $1000 to weld it. it looks like a $200 job.

 

It would take 15 minutes to prep it using a deburring tool, 5- 10 mins to fill it up. 5 mins to reshape it. Not a big or expensive job. Upto you but that's the top and bottom of it

 

Where I am there are a lot of highly skilled welders, and they also get paid very well. I used to work at an oilfield equipment fabricator that operated in many countries and had about 1000 employees. The only people who made more than the specialist welders was the President and CEO. The VP, and all the Processional Engineers made less than the welders, simply because the welders were in such demand. In my city, finding a TIG welder willing to do that small a job would be difficult.

I knew some pressure vessel welders working on a remote project that was a fly in-fly out camp up north who were making $80,000 a month....

 

If you want a numbers matching engine yes weld it. But the reality is I’ve got a spare good block you can have for $200 add crating and shipping from Mpls. it’s there. But there has to be hundreds of them local to you.
Nothing wrong with them except the mechanic can’t figure out how the EFI works and yanks it to put a Chevy in it. ( ‘cause he know’s those)
That or the car was wrecked or rusty.

 

I really do appreciate the differing opinions here. One of the reasons that this forum is such a valuable resource is the varying backgrounds and expertise on offer here.

Even though our XJ-S's are unlikely to ever attain the status and collectibility of XK's, MKII's, XKE's, etc. we are seeing values rise and I would obviously rather have a numbers matching car than not. That being said, my plan for this car has always been to tear it down and "do everything right, do everything once" so that I can enjoy the car for many years to come without major headaches constantly popping up. I've owned several XJ-S's and I intend to keep this one forever. There's ample evidence of negligence and carelessness throughout the mechanicals of this car and my goal is to put everything right so I don't have to worry about anything on long road trips etc. etc. (not least of which the starter flange breaking off someday)

I was already in the market for a parts car before discovering "the crack", and this recent development has "sealed the deal" so to speak. I can use the spare IFS and IRS to transport the car while I'm working on my own suspension, and having a second engine will be good insurance depending on which route I take with the cracked block. I'm thinking that I'll strip the block down and get a few quotes on welding it before I make a final decision. I don't like the idea of "wasting" the original block either but unless I can get someone to guarantee that they can make it as good as new I'll be swapping it out. Yes I agree the crack has most likely been there for years and hundreds of start ups but it doesn't make sense to go to the expense and effort of a full rebuild on a block that's compromised in any way, especially when V12's are still a dime a dozen where I'm located.

On a lighter note, the IFS is complete; photos below. Next up is the IRS with the engine work proceeding in parallel. (Ignore the disorganized garage- I'm without a garage at the moment so the project has been relocated to my mother's house for the time being)

 

Very very nice job, congratulations.
As to the crack: from the two photos it seems the crack as well runs down to the bottom in a sort of L shape, as well as just straight through the casting as it looks to in the first photo:

If I am right, then the entire weight and any reaction to the starter's work is being taken by the "outside" side of the hole the starter bolts up to. Thus the bottom thicker part of the casting is doing nothing in the way of supporting the starter. Now I agree that a good welder can weld anything, and as long as a wide V is ground ALL ROUND the crack and then welded and filled I am sure it will be strong enough.
Another option before welding (or even instead of, if a welder is hard to find or not confident) though it is hard to see if this would be possible except if actually looking at the engine for real, is to drill and tap a hole (tapping just the part of the hole attached to the main engine casting) and insert a bolt through the main part of the crack and lock it in with the super duty high strength Loctite that cannot be undone without 500 degrees C heating. This would do the job fine, IF there is enough meat there to do it. Or even the placing and welding in situ of an external strip of metal along the bottom edge of the casting, as shown in the pic in this post.
Remember also, that the starter turns (looking from the front of the engine) COUNTER clockwise, as it is turning the ring gear and engine clockwise. Therefore, I think, and I am open to correction as always, the torque of the starter motor is tending to push the crack closed, NOT lever it open. This also means a decent repair should work, as the repair is not taking tension when the starter is used.
I suspect that had the crack been at the top of the hole, the thing would have failed very quickly.
I believe the main danger of the crack, in fact, is that the casting actually snaps off when going along, as a result of the vibration of the engine/chassis gradually making the unsupported top part of the "hole" fail.

 

Greg, I think you are correct that the "twisting" force of the starter puts positive pressure on the cracked area, and if it were the other way around would have likely failed a long time ago. Perhaps this pressure on startup is responsible for forcing the starter flange ever so slightly lower than the block, shown by the ridge along the cracked area. I remain skeptical that a repair to this area can meet my admittedly obsessive standards, but it's in tension with my desire also to keep the original engine with the car so, "we'll see".

I'll come back to this thread once I have a definitive answer, but with the pace of life at the moment it may be a while before I have the engine down to the block and can bring it to some shops for quotes.

 

Introducing, "Return of the Saint" XJ-S!

I picked up this 1985 example for a grand. 63,000 miles, been in a barn since 2002. The car is trashed on the inside and there's a good bit of rust on the body so I have no qualms about salvaging it for parts. In fact the interior is something of a biohazard so I'm eager to strip it for parts and be rid of it as soon as I can.

Before purchasing I verified that the engine turned over freely (by hand) and the engine oil dipstick and coolant passages look excellent. Haven't done a compression test yet but since I plan on rebuilding it anyway, not a huge concern. I was told it was parked when the old lady that owned it started having trouble getting in and out and then the rear brakes went metal to metal.

No final decision yet on which block I'll end up building, mating to my Tremec TKX, and dropping back into old "Blackjack", but it feels good to have options (and 2 sets of everything).

When I have removed everything I need off the car I plan on making a new thread offering up all remaining parts to the community for only the cost of shipping & handling. Whatever is left after that will go to the salvage yard. Ideally I'd like as little as possible to go to waste.

 

Really good find. I bought a parts car and it saves loads of money, loads of time, and all those little trim and other parts that are NLA are there.

 

Just don't scrap the old block - that is totally repairable, just needs the right person - crack needs to be ground back, the ends of the crack need to be identified but once the block is squared up then welding it up isn't that hard but the weld needs to go deep - a surface only weld will fail again.

This helps you keep matching numbers even if it sits at the back of the garage / store for a time.

Just add one experience here - I have a two car garage full of parts that I'm falling over and it looks like you will have a fair amount, labels are mandatory, don't throw away any nuts or bolts and label those too - trust me some are hard to replace and are easily lost. Store the parts in assemblies and don't break them down too much, if you have the space don't be in such a hurry to be rid of the car - it is the best place to store things and also provides an 'assembly' reference so getting somebody in to deal with the biohazard may be a better option. If you can't then store the entire front hub as an assembly or even the entire IRS and IFS - don't tear it down beyond your needs, even the engine - but for the engine consider changing the oil for new stuff, removing the plugs, crank the engine to circulate the clean oil and make sure the bores etc get oil filled prior to storage, the cooling system needs to be totally dry or you should use a 75% concentration of 'anti freeze / anti corrosive', the fuel system needs to be fully purged / filled with a zero ethanol fuel such as 100 octane aviation gas (injectors don't like to be stored dry for prolonged periods), I spray all 'oiled' surfaces with a heavy cycle chain oil - that means cams etc etc, even the outside of blocks and transmissions - any metal surface will attract rust or corrosion, I spray trim and fittings with transport wax and do not store above open ground or grass.

Consider selling off some parts to fund the project (I lack this discipline - my place is like Hotel California for car parts - they check in but they never leave).