[Mguilicutty]

Hey guys, I've been a LWB owner for about 9 years now but after someone rear ended me (not catastrophic) and two weeks later the oil pump went out I decided to put the LWB away for a little while and add a second Rover to the fleet. I came across a 2000 HSE that is in very good shape other than the engine. The shaft on the water pump had come loose leaving the pulley dangling off the end of the pump. The previous owner had his friend work on the truck, and it appeared he was intending to do the head gaskets and gave up hence the reason for selling the truck. The AIS pump had been removed, the upper intake was partially removed, as well as the maf and all related plumbing. Nothing was missing, the EAS pump was recently replaced, the engine would turn with a wrench with the plugs removed, and everything else seems to be in good order. I picked up the truck for $2500 and towed it home.

I decided to go ahead and do the head gaskets, as the work had already been partially done. I disassembled the rest of the way and everything went smooth except the rear 3 or 4 bolts on each head came out very easily. I took the heads to the local machine shop and they cleaned and pressure tested them, ground the valves and the seats, put in new seals and surfaced the heads. I do not know how much he surfaced them.

Everything was going well until last night I went to put the lower intake back on and it does not seem to line up. I put the new gasket seals in place, positioned the clamps, and bolted but not snugged them in. I put the valley gasket in and it would not line up correctly. It seems like if I line one side up, that it is too wide and over shoots the bolt holes on the other head. I figured maybe it kind of pressed into place once the lower intake is pressing on it so I go and put the intake on and I seem to be finding the same issue. And it's driving me nuts.

The heads can't be in the wrong place as the are located by studs in the block. When I bolt one side, the opposite side does not line up, I can see maybe 3/4 of the hole the bolt should go in, maybe more. I can force the bolt in without cross threading things, but not all the way, and upon removal, the bolts threads were starting to cut into lower intake. Is it possible that the shop ground the heads down so much that the intake no longer fits?

If so, and I'll be calling them on Monday, what am I looking at? I could conceivably machine the lower intake a bit and it would fit, the valley gasket might be a challenge. New heads? Taller gaskets? I'm going to go look at it with fresh eyes here in a bit, I was about 6 hours into it late last night. Thanks for reading my long winded post, and I have pics of the whole process if anyone is interested.

 

[viperover]

Its possible that the heads are over skimmed but the intake manifold can trimmed to fit, a good engineering shop how do alot of these motors will know what to do

Please also note that there is a special tightening sequence for the manifold and new head bolts must be used

 

[Mguilicutty]

An issue with the heads being over skimmed is my compression ratio could be way out of wack now. Is there a way to test this without removing the heads again? I'm following the workshop manual and I did get new bolts for the heads and the rocker shafts. Also, if I take the heads off again should I get new bolts again?

Thanks!

 

[viperover]

I wouldnt remove heads and if you do new bolts woulb be required although you havnt started engine, as a matter of course I would...

If its over skimmed you'll have slightly more compression but its not going to be drastic
Have you tried getting bolts on one side of inlet manifold and noted how mush out the holes are out by

After all the work you have done so far I would get inlet manifold sides lightly trimmed

 

[Mguilicutty]

Okay, so today I went back and took another look things, and snapped a few pics that might be useful. First, the left head, apparently I had already put the right one on before I remembered to grab the camera.

[attachment=4:3dwvurcr]IMG_2597.jpg[/attachment:3dwvurcr]
[attachment=3:3dwvurcr]IMG_2598.jpg[/attachment:3dwvurcr]
[attachment=2:3dwvurcr]IMG_2599.jpg[/attachment:3dwvurcr]

Unfortunately, I do not have pictures of the heads from before I sent them to be machined, in my defense, it was around 0 degrees F outside when I took them off. Next up, I took some pictures today to show how the lower intake is lining up. I removed the valley gasket before I took the pictures so we can see down the holes better. In the pictures, the intake is being held in place by two bolts on the front and back of the right cylinder head, and I pushed it over as far as possible before finger tightening the bolts.

Here, it is kind of hard to tell, but on the right head (left in the picture) there is about a 1/4 or maybe 3/8 inch gap between the edge of the intake manifold and the machined edge on the head where the rocker cover mounts. On the left head, there is no such gap.

[attachment=1:3dwvurcr]IMG_2612.jpg[/attachment:3dwvurcr]

This better illustrates the lack of space on the left head, it is about 1/16 of an inch. You can also see down the second bolt hole on the manifold, and how far off it is.

[attachment=0:3dwvurcr]IMG_2611.jpg[/attachment:3dwvurcr]

 

[RRToadHall]

The first that comes to mind is that they must have shaved one heck of a chunk of head material to be that far off on the intake. The intake is very forgiving in it's alignment. This will also present a possible issue with valve clearance. Before going any further very slowly turn the engine over a few times and make sure you have no valve/piston contact. If not you are at least going to have quite a compression ratio change. Many times folks shim their rocker arm posts to compentsate for the head shave. ALthough not necessary it will be your main option if you have valve contact.

 

[Col]

The first that comes to mind is that they must have shaved one heck of a chunk of head material to be that far off on the intake.

Slightly worrying that because according to Rave maximum re-face limit is 0.50mm or 0.020" which ain't a lot.

Cheers

 

[rtkraken]

I just checked a very similar set of photos of my heads before I put them on. It's hard to be exact, but the cupped casting depression and valve cutouts appear to be about the same. That is a heck of a lot of mis-alignement! :shock:

Please pardon the stupidity of this question... did you use the composite head gaskets or perhaps somehow got ahold of a tin set? Can you spin any of the valve pushrods with your fingertips or are they all pressed tight?

 

[RRToadHall]

I went out to the shop to look at a couple of sets of virgin heads and a couple sets that have been skimmed. In looking at pic 2597 your intake casting edges on your head have been shaved as well. On my virgin heads these casting edges aren't close the head surface level. On the shaved heads they are naturally closer, but still are rough cast edges and were not touched by the skimming/shaving process. It jsut really looks like they took a HUGE amount of material off in the skimming process. Those heads must have been mighty warped to have to go that far... unless there is another explaination that is escaping all of us thus far.

 

[viperover]

Many times folks shim their rocker arm posts to compentsate for the head shave. ALthough not necessary it will be your main option if you have valve contact.

Never skim rocker posts, when skimming heads you can shim up the posts if you like, RPI website describes this in detail.

Heads in pics need to be measured as there is a min thickness they can operate at, Ive seen worse hole alignment and worked well after a skiming of inlet, your only issue is finding someone who is willing to go the extra mile

 

[rtkraken]

In looking at pic 2597 your intake casting edges on your head have been shaved as well. On my virgin heads these casting edges aren't close the head surface level. On the shaved heads they are naturally closer, but still are rough cast edges and were not touched by the skimming/shaving process.

Ditto in the pictures of mine. I noticed that too, but wasn't sure if maybe the machining process was stopped before it got to the intake edges.

If this leads to replacement heads I've got a good source for a clean set of remans. $199 pc (plus core charge).

Hopefully they won't be needed...

 

[ferret]

there does not seem to be any shims mounted, did you check for lifter preload?

 

[RRToadHall]

Many times folks shim their rocker arm posts to compentsate for the head shave. ALthough not necessary it will be your main option if you have valve contact.

Never skim rocker posts, when skimming heads you can shim up the posts if you like....

:? Isn;t that what I said?

 

[viperover]

errrr, I missed that bit somewhere....

 

[diff]

If the shop can not or will not tell you how much they took then you may be forced to pull one and measure the combustion chamber volume and compare the volume to a published standard. That would likely assist in determining the amount cut.This really seems like a nightmare in the making and I can only offer moral support at this time. I hoppe rr is correct and its just something simple that hasn't been thought of yet.

 

[ferret]

from Rave, not sure if it will help

 

[john Faturic]

Hi my 2 cents worth intake manifold not same as 4.6 on my 96 is it posible that it is wrong,
good luck.
John.

 

[RRToadHall]

Hi my 2 cents worth intake manifold not same as 4.6 on my 96 is it posible that it is wrong,
good luck.
John.

:think: If it came off the engine before the rebuild, shouldn't it go back on?

 

[Mguilicutty]

Sorry guys, I didn't have time yesterday to spend on the truck, today, I have about an hour so I'll try to respond to everybody. First off, I can rotate the engine by hand with no apparent mashing of pistons / valves. Though I would be concerned it may be possible at high revs and that the compression ratio may be so far out of whack that running without pinging may not be possible.

I did use composite gaskets. I purchased the Elring gaskets from AB. Also, I can spin all the pushrods except for 4 or 5 of them that are up on the cam. I did not check the preload, I'm not real sure on how to do that but I do remember reading about it at RPI.

I contacted the shop yesterday and they do not have records and can't remember how much they shaved off. Ferret, I'll be sure to take those measurements and post them here if I end up taking them back off. And finally, the intake changed mid 99 with the introduction of the Bosch EFI.

I'm still hoping for something simple to pop up! However, I think I'm going to be stuck having to find a new set of heads, and the air injection heads seem to be far more expensive than the regular ones. My wife is going to kill me... Skimming the intake I think would be possible, but I think too much material has been removed from the heads for the motor to ever run right. The valley gasket would have to get pretty mangled and might not seal correctly, and if it didn't work I'd be out an intake as well.

I'm going to give it a few more days for the collective RR mind to stir something up but I think thats where I'm at. So far, the RPI stage 1 heads are looking pretty good but shipping may change that equation. RTKraken, where are you finding rebuilds for $199? That would sure lighten the beating I'm going to take from the wifey. :doh:

 

[Keijo]

Mgguillicutty,
The heads are obviously lower and closer together as a consequence of the skimming.

It is possible to compensate for this by shaving the heads again but at the face that mates with the intake manifold.
There would be more meat there than shaving the manifold itself.
By doing this you will separate the head inlet faces slightly and allow the inlet manifold to drop lower and the bolt holes to line up.
Additionally, if you then line up with the original untouched manifold, you know your gasket will also fit

Some simple measurements and geometry will give you the amount needed to be removed.

This of course wont fix any issues you may have with compression ratio but I feel that may not be too big a deal.
Anyway, it's another low cost option to consider.
You may even be able to get the shop to do it for nothing, seeing as they overdid the first job, eh.

Cheers,
Keijo