Where to from now???????

 

Firstly - sorry for the lack of updates. Life outside of the car has been really hectic so the speed of progress is less than I'd want. It's still happening.

I'm going to be going with ARP for the head and main studs. They do a set of head studs off the shelf that will fit. They do a stud & nuts to fit the inner M10 main stud, but not the outer M8 main stud, so I'm investigating custom ones.

On the piston side, I have a factory piston with Mahle in the queue to be scanned - they have a 92.5mm ring set and a forging that they usually use for turbo'd Subarus they reckon will work nicely, so it's looking good on that front.

In non-engine stuff, I'm in the process of learning TIG welding to modify a rather large universal aluminum radiator I've bought for the charge cooler. I'm also investigating hood vents for to try and combat some of that heat soak!

 

So I bet you all thought I'd given up - not quite there yet, but sadly the car has taken a bit of a back burner position these last couple of months. Here's a couple of progress photos though.




ARP studs/bolts for the main bearing caps



M10 main studs in place



A cap bolted in place with M10 studs/nuts and M8 bolts



Main bearing caps torqued down

I have a set of standard crank and rod bearings on order, they should be here in a week or so.

I've had a quick go with the dial bore gauge and the crank journals don't appear to be out-of-round, but I'll need to talk to ARP about what torque I should be using with the bolts before re-checking, because otherwise it'll need a line bore hone (which I'd rather avoid). I'm also thinking I may not be able to use ARP rod bolts any more as the rods are fracture-split, so you can't resize the big ends if you need to with the ARP bolts, and I'm not sure my budget will stretch to having custom forged rods made, especially with the additional time this will add to an already overrun project.

Not all this time has been wasted though, here's a spyshot of my Work-In-Progress attempt to address heatsoak in the engine bay




Needs a bit more work and then it should be ready for paint. I have a lot more photos of the process I went through to do this, so I can chuck them up once it's done.

 

glad to see your engine project is still alive .


regards
Ulrich

 

Hey Dave,
I have a 2016 Jaguar F-type with a bad connecting rod... We are attempting to rebuild it but its a nightmare sourcing parts. Any Suggestions? Let me know! thanks Ben

 

Out of warranty?

 

Water damage no warranty

 

As people will often tell you, Jaguar don't list or sell the block internals for the 5.0 engine, but that doesn't mean that you can't get them.

Main/Conrod bearings

Conrods

If you have piston damage then you can source new pistons from the eBay seller above, and they also sell Ring Sets.

For any other parts, I'd enquire with that eBay seller who have been helpful with me, along with maybe trying to contact Range Rover rebuilders, as they seem to rebuild this engine quite often.

 

Couple of quick pics

I test fitted the crank with new bearings to check clearances

Crank test-fitted in block with bearings torqued up


Plastigauge shows clearance of .0015" on all main journals, which I'm pretty happy with

This next bit I was expecting, but it's still a bit of a pain. The ARP studs foul the windage tray, as the factory clearance at the top of the main bearing caps was just enough for the OEM bolt heads. For 9 out of the 10 studs this is not an issue as I can cut necessary pieces out of the windage tray for it to fit, but for the last one in main bearing 1, there's a threaded hole right above where I need to cut out which is used by the timing gear:



My plan is to shave as much as I can from the bottom, and also inquire with ARP what the next smallest stud size is. If I can't get a suitable size I'll have to cut the thread of this one down, which I'd rather not do but can if necessary.

Next step is to re-check the roundness of all main bores with the ARP bolts torqued up to make sure line honing is not required, but it's looking like I might have got away with it.

 

Quick update: with some careful measurements, I reckon I'm at about 0.0007-0.0009" out-of-round on the main bores with the ARP nuts torqued to spec, which I think is a bit far out for my liking so I'm going to look at getting the block line-honed.

Also, I've decided against ARP for the head bolts, I'm just going to go for the factory ones, for a few reasons:
- the cost (!), the set that ARP found matching the measurements costs about 4 times as much as other head stud kits, I suspect because it's intended for a Porsche
- this kit is also intended for a comparatively low-torque application in this Porsche engine
- quite a few people recommend checking the torque on the ARP nuts after a few heat cycles, but on this engine that requires removal of the camshafts to access the heads of the bolts, and you'd have to remove quite a bit of the timing gear too.

Based on this, I think I'd rather just go with factory head bolts where I can torque them up and forget about them.

 

Honestly DT, I wouldn't cut away at the block I'd trim the studs, Just a quick rule of thumb I learned working on USAF spec equipment, the minimum thread count that must be seen on any nut and bolt being used for retention was 1.5 threads above the nut, that was considered full thread engagement. Just take the bolts to a good machinist and have them turned down to the length you need.

 

Ditto, or find a sacrificial nut to thread onto the stud and use a whiz wheel to cut the tip off. Then belt sand or file the cut at a 45 degree angle so the thread is blended and run the nut off to straighten the burr at the cut.

 

nope. I would go factory head bolts. First, your load factors are reversed using the set-up you are trying to implement. Think of a nut working itself loose. Also, having to shave down all those threaded pins wont be fun. why not the factory setup to begin with?

 

Think there's a bit of confusion going on here - I've gone with ARP studs on the main bearing bolts because the factory bolts are not available. The clearance issues are not with the block but with the windage tray, which I'm far less concerned about cutting down to allow clearance for the studs - the only problem is with one of the studs on main bearing 1, as there is a threaded hole in the windage tray which is used by the timing gear, so yes - I will turn down this one stud at the front. I'll try and get some pictures up to explain this better, but needless to say it's all in hand

The head bolts are a separate issue, and I'm going with factory bolts for them for the reasons I listed above.

 

Do you have any idea what caused the out-of-round condition? From my limited engine rebuilding experience, line boring or honing of the mains is usually not required since the mains are doweled or indexed to the block and it takes a lot to change their dimensions or position. I would be more concerned with the boring/honing process raising the position of the crank in the block relative to the seals and transmission input.

 

From my understanding, the increased clamping force of the ARP studs vs the factory bolts can cause this, which is why ARP recommend a line hone after using their main bolt kits (see the "FOOTNOTE" on the instructions for one of their main stud kits). From what I've been told, the measurements are so small here that it wouldn't result in much more than a "dust" of the main bores with the mandrel to bring it back into round, which shouldn't have any adverse effect on the position of the crank. I'll talk to some machine shops about this first though.

The reason I've gone with ARP studs/bolts on the mains rather than factory bolts is firstly that the factory bolts, like a lot of things, are not available from Jaguar and I'm also struggling to source them from rebuilders, but the other reason is that the factory bolts are torque-to-yield and they are generally only good for about 5 torque cycles, meaning I could probably reuse the old bolts maybe once if I was just changing a bearing out or whatever, but with the work I've been doing I've needed to torque them up multiple times, which is where ARP becomes a good as well as cost-effective option.

 

I'm not trying to question what you are doing but are you sure the bearing cap bolts are TTY? I looked at the manual and there's not much other than the torque and angle values for the M10 and M8 fasteners. Where you able to find something that requires the bolts be replaced?

 

It's a fair question, but I figured that the fact it has an angle in the spec is probably a good sign that they're TTY, along with the fact that re-using main bolts on any engine is generally considered to be not a great idea - the same applies to the conrod bolts, and Jaguar is pretty insistent about not reusing those.

Also, the rebuild manual for the 4.2 engine (since the 5.0 manual does not include rebuild instructions for any of the short block) states:

.

(the bed plate performs the same function as the main bearing caps on the 4.2)

I'm not speaking from any authority though, fastener sciences is beyond my level of expertise, and I'm of course open to all input!

 

I appreciate the willingness to discuss, often times these threads dissolve into valueless arguments when questions are asked. Just my opinion, but I would be concerned that using the new fasteners may have resulted in a change to the clamping force on the mains (42lb-ft +70 degrees vs 60lb-ft) which necessitates line boring/honing the crankcase. I'm sure there is a calculator out there (or someone smart on the board) who can calculate the equivalent torque for the 42lb-ft +70 degrees and compare it against what ARP specify for their studs. If there is no significant difference I can't see why the line boring would be required. If there is, you could be changing the stiffness of the crankcase in that area which could change it's response to loads. Is there any information on the Jaguar bolts that might indicate the material used?

 

I tried finding that kind of information but it was pretty much impossible. ARP's technical support were not really willing to give any kind of a torque figure based on a torque + angle measurement of the original bolt as they'd need a few OEM originals to perform tests on which I'd imagine don't come at all cheap.

I guess one thing I can do is refit the mains using the old OEM bolts torqued to OEM spec and measure the out-of-round again to see if it differs - you're not supposed to use them again but I suspect they won't snap. Personally, I think the affects on the stiffness of the crankcase are likely to be immeasurably small and therefore I'm less concerned about that, but good to cover all these bases.

The biggest issue at the moment is that the 5.0 workshop manual has general information of how to check bore sizes, but doesn't list the out-of-round tolerance spec.