Has anyone rebuilt the bottom end of their V8?

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SLVRobin

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Hello all,
I purchased an engine to rebuild and am currently in the midst of tearing it down. I have the factory manuals and they all the sudden stop when you get to tearing into the engine block. After you get the engine stripped down to the short block the manual goes into putting it back together! There is very little information on the pistons, main bearings, connecting rods, etc. It does cover these things for the V6, but nothing for the V8.
I do not know the condition of this engine and it was purchased with the intent of a complete rebuild, so I am not real excited about just calling the short block good and hanging new or rebuilt parts on the outside!
Has anyone rebuilt their crank/bearing/piston assemblies and if so where did you get the information?

Thanks
Robin
 
The official attitude toward engine rebuilding is shown by the fact that you can't buy bearings, you buy a block and the bearings are in it.

I bought a 4.0 litre Jag engine (AJ 27) to re-do for my '02. You can get a fairly complete picture of my goals by reading 'Land Speed LS' in the HP section. I ordered bearings from England and had a crank done by Moldex. My rods are by GRP and pistons from Ross.

I may get inserts for the block to make possible the use of HP SBF main bearings. The smaller bearing journals slow down the surface speed and reduce friction. Feel free to PM me for info or post specific questions here and I'll try to answer them.

KS
 
I haven't torn one down but, I have a friend that is a diesel mechanic that bought one from his brother. The car had a bottom end knock. I want to say he put mains in it. He may have done it like mentioned above. I do know for a fact he built the bottom end and the car ran perfectly until he wrecked it.
 
Thanks for the info gentlemen.
Ken, I am beginning to read the Land Speed LS...great so far! I agree with you on one thing in particular. When I started breaking down the engine in my garage it was great seeing all of the Hot-rod things that were inside! Windage tray, main girdles, DOHC, aluminum blocks and heads...pretty impressive stuff for a Lincoln "passenger" car! Quick question...do you know if the main bolts are stretch bolts? I have not gotten very far into the other thread, so maybe it answers this but did you switch to main studs, and did you just follow a circular pattern in the loosening/tightening sequence? I don't want to warp anything by unbolting in the wrong sequence!
Thanks again guys.
Robin
 
I have found some info for jag engines. Go to jaguarforums and search for "jaguar university" and a download for "Engine repair course code 168" for v6/v8 engines. The description of the engine bottom end assembly is around 50th to 60th page of the download. This is for a JAG NOT LINCOLN LS engine. Follow at your own risk. I'm not liable for anything.

I have found that some stuff differs between 4.0 and 3.9 engines.

Good luck.
 
Sorry I missed your post. I believe the bolts are 'stretch' style. I went to ARP for studs and nuts. Started in the middle and went, alternately, to both ends.

KS
 
From everything I have read (not done) you can pretty much use the Jaguar 4.0L bottom end in the LS as long as you put the LS oil pump on it in the gen2. The cam timing control is oil operated and needs the higher volume/pressure pump found in the LS.

From what little information I have seen the 4.2L bottom end will work as well but might need some cooling passages drilled to match the LS heads. The 4.2L block also has oil sprayers that shoot up under the pistons to help cool it down and the higher volume/pressure pump for the oil-operated cam timing.

Keep in mind the only person on this board who has gone down this road and documented it is cammerfe. There was another guy who started but never updated his thread with anything past the discovery/researching stage.

The bottom end bearings are somewhat of a pain on these types of engines regardless of how you go. Honestly if you don't have the proper tools to measure everything you are better off having the bottom end rebuilt by someone else. The jaguar instructions, which are the only ones anyone can find, requiring measuring the journals to within 0.0001" accuracy. That's a pretty tall order for your standard run of the mill bore gauge. If you find a shop that is known for rebuilding Jaguar, VW, Porsche, or a 'boxer' style engine they should have the proper accuracy gauges to measure everything.

Plan B is to take meticulous notes of what color code bearing half is in each part of the engine on disassembly. Keep in mind the block side of the main bearing may be different then the cap side and may also be different from journal to journal. Same thing with the rods.

You should also get a ball hone (or dingleberry hone) to run through the cylinders on the jag block. The cylinders are chrome/nikasil so you can't really hone them much. Inspect the cylinders well for chips. Make sure you are moving the hone up and down fast so you don't burn the cylinder and use lots of oil or WD40 as lube. You don't want it to run dry. The ideal hone finish should look like 45-degree intersecting lines. Repairing the cylinders is expensive so look for something that was running and wrecked as a donor vehicle.
 
Jaguar only used the Nikasil process for a short time back around '98-'99. There was a period when the fuel available in Europe had high-enough sulfur content to cause damage to the embedded silicon in the treated bore surface and warranty claims went right through the roof. At that time there was a running change to cast-in-place ferrous cylinder liners. All 3.9 engines and almost all of the AJ series from Europe have the ferrous sleeves as well.

KS
 
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AJ engines aren't 'Mod' motors. They are, in fact, almost entirely different. Mihovitz has a deserved reputation as an engine builder but knowing about Mod motors isn't an automatic guarantee of similar skill with a different design.

KS
 
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cammerfe said:
Jaguar only used the Nikasil process for a short time back around '98-'99. There was a period when the fuel available in Europe had high-enough sulfur content to cause damage to the embedded silicon in the treated bore surface and warranty claims went right through the roof. At that time there was a running change to cast-in-place ferrous cylinder liners. All 3.9 engines and almost all of the AJ series from Europe have the ferrous sleeves as well.

KS
Click to expand...


Learn something new every day :)

I used to deal a lot with chrome/nikasil cylinders when I worked in a machine shop rebuilding marine engines. They were a pain to deal with. Get them too hot or hone to aggressively (or dry) and you'd end up ripping the finish off. Sleeved more engine then I care to remember.
 
Well, I appreciate the comments everyone. It has been a while since I have looked here...got a new job! Anyways, as luck has it I am now a Quality Engineer at Kurt Manufacturing (the machinist vise company) and we have a huge library of ultra-precise measuring equipment! The plan is to measure the crank journals to see what the worst case is, purchase a single bearing set to the closest standard undersize that I measured my crank at, see if the bearings physically fit in the block, have the crank ground to this size and purchase the rest of the necessary Jaguar bearings. I talked to my crank builder and in the far past you would bring in the block, caps, bearings, and crank and they would fit them all to the bearings, but he said that measuring technology and equipment has gotten so much better that he just needs the crank and undersize I am going to and they will grind it. Cammerfe, do you have an ARP part number for your main studs or were they made for your engine to your specs. I got their catalog but I don't see a part number for this application. It might be a slow go, but I will report everything that I see and do (torque specs and sequences, mods needed to bearings...if any, part numbers for the studs, bearings, etc.) so everyone has the information needed to replicate the process. If anyone has more information please keep it coming.
 
You don't buy a 'set' of main bearings for an AJ engine. I got mine from a source who have a direct link to England. You buy individual shells at about $6 each, mix-'n'-match for sizes, to come up with proper clearances based on the crank journal diameters and the finished sizes of the saddles in the block you have.

I called ARP and gave them the sizes of the fasteners I needed and they supplied me with what I asked for.

Please DO keep us updated. And congrats on the new job.

KS
 
Been a while since I looked but I think the Jaguar manual doesn't really have an undersized option. If the journals cant be polished or are out of round you might have to go shopping for a new crank. I want to say there was only like a 2 or 3 thousandth range in the stock main bearings.
 
Hey Kumba,
I gotta ask. Although I'll bow to no one in my admiration for cannolis, and I regularly carry a Kimber, I am a bit puzzled by the juxtaposition. Care to enlighten us?

KS
 
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leave_the_gun_take_the_cannoli_by_6amcrisis-d497euo.jpg
 
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