Replacing head gasket questions

[rqsall]

OK, not wanting to hi-jack the "95 SWB smells like coolant thread" (95 SWB smells like coolant and blows air bubbles)
I have a couple of questions on replacing my head gaskets. Already posted this on rangerovers.net forum, but haven't got any actual answers there. Seening as the predominant topic here is head gaskets, I figure I'll try my luck here

Seems like the gasket blew at cylinder 1, between the coolant channel and the combustion chamber. Now I have the choice between going the original route of metal gaskets, or composite ones.

I am aware composite ones cost you a bit of compression, but I'm not worried about that. What I wonder though, is if I need to change anything else if I switch to composite gaskets:

1. Do the pushrods need to be replaced for longer ones, because the composite gasket is thicker, the distance from the camshaft to the rockers is larger? Or does the self adjusting nature of the hydraulic tappets take care of this?

2. Because of the reduced compression is the engine characteristic changed in such a way that the ECU needs to undergo re-chipping?

For completemess, it is a 1991 Vogue (non-US, same as Hunter in the US I believe) with the 3.9 efi engine. (14 head bolts, as opposed to the newer 10 bolt heads), compression ratio is the higher 9.35.

Another thing that puzzles me, is how the coolant flows out of the cylinder head into the intake manifold. According the the shop manual that is how it flows, but I can't see how when I look at the heads.

Thank you very much for any input.

[TerryS]

Originally Posted by rqsall

OK, not wanting to hi-jack the "95 SWB smells like coolant thread" (95 SWB smells like coolant and blows air bubbles)
I have a couple of questions on replacing my head gaskets. Already posted this on rangerovers.net forum, but haven't got any actual answers there. Seening as the predominant topic here is head gaskets, I figure I'll try my luck here

Seems like the gasket blew at cylinder 1, between the coolant channel and the combustion chamber. Now I have the choice between going the original route of metal gaskets, or composite ones.

I am aware composite ones cost you a bit of compression, but I'm not worried about that. What I wonder though, is if I need to change anything else if I switch to composite gaskets:

1. Do the pushrods need to be replaced for longer ones, because the composite gasket is thicker, the distance from the camshaft to the rockers is larger? Or does the self adjusting nature of the hydraulic tappets take care of this?

2. Because of the reduced compression is the engine characteristic changed in such a way that the ECU needs to undergo re-chipping?

For completemess, it is a 1991 Vogue (non-US, same as Hunter in the US I believe) with the 3.9 efi engine. (14 head bolts, as opposed to the newer 10 bolt heads), compression ratio is the higher 9.35.

Another thing that puzzles me, is how the coolant flows out of the cylinder head into the intake manifold. According the the shop manual that is how it flows, but I can't see how when I look at the heads.

Thank you very much for any input.

The difference in compression between the two gaskets is very minor, but if you are concerned, you can have your heads planed. It's always a good idea to have them checked for cracks andflatness anyway, so while they are out, have them take off .012-.015".
The new gaskets are not even punched for the bottom row of holes. Use the new torsion torque head bolts, not your old ones. I don't think LR has yet made a torsion bolt to replace the special one used at the alternator mount.

The hydraulic tappets will adequately compensate for the extremely slight increase in distance. Some purists insist that the rocker arm mount pads on the heads need to be milled down.
Little can be done apart from expensive performance chips, to the 14CUX ecu. Splitting hairs, in my estimation, and little is gained for the money.
I did the 3.9 over in my 110 and did nothing, and never saw the difference. When I built the 4.2 for the truck, I took .025" off the heads (intentionally) and that engine is killer (non stock cam, but standard rockers, flat wound diesel engine valve springs, so no spring pocket milling necessary)

Even though there is a water passage port in the head at the front of the heads, there is only a vent hole in the block, not a true passageway. Water travels to the heads via the ports at the rear of cyls 7 & 8. It then goes into the intake via ports at the corners.

Heres a trivia question: The idea of 14 headbolts is a Land Rover stroke of genius. How many head bolts did the original Buick engine use?

[sven]

Originally Posted by TerryS

Heres a trivia question: The idea of 14 headbolts is a Land Rover stroke of genius. How many head bolts did the original Buick engine use?

Is it 14

[rqsall]

Thank you for the great reply. Yeah, I am going to have the head planed, but just enough to make sure it is flat. Going to use new bolts as well, the special one for the alternator mount is a stud right? There is no torsion replacement for it?. Not worried about the loss of compression in terms of performance btw. Was just thinking about the consequences of the thicker gasket. Also, the intake mounting and gasket is not affected by the added thickness either?

I see where the water passage port in the head is now. I mistakenly thought it was an intake port, guess I need to learn to count before working on Land Rovers

No idea how many bolts the original Buick engine had, but I doubt Land Rover changed much.

Thank you very much. I think I'll be going for the composite ones, although the original metal ones held out 120k miles. I'll be happy if it does that again

[TerryS]

Sorry for the delay to answering the Trivia question re the # of head bolts.

It was 18. Each cylinder was equally surrounded by 6 bolts (at 60 degrees apart, duh) which is very logical. LR dropped that pattern, and without logic, kept the bottom row of 4, and altered the spacing around the cyliners, not smart when engines were producing more HP, with the resultant increase in cylinder pressures.
When it became evident that the bottom row of 4 bolts was the likely cause of so many head gasket failures, due to the uneven tension, they dropped that row, because there were so many engines out there.

I have one of the old 18 bolt Buick blocks (and the heads) and I justify not having junked it out by telling myself, since it's a good block, that someday I'll build an engine from it. Later 14 or 10 bolt heads won't work. I took a picture of the block deck to post here but the picture turned out to be 1.72 MB, and I'll have to go retake it in some other mode.

[rqsall]

18 bolts eh? Go figure. And then to think that Land Rover (actually British Leyland) bought the design from Buick, because they were unable to design a reliable V8 themselves (Triumph Stag anyone?), and still thought they could make an improvement to an already proven design, gee...

Thanks for the answers

[boxer]

I have (2) 95 classics SWB and one of them also has leaking head gaskets. My local estimate was $1800, didn't even bother going to the local dealer.

We are going to be selling the nicer one next week (on ebay...shameless plug I know) so we defiantly want to keep the other so we will be fixing it soon.

My thought was to buy a 60K mile engine for $2000 from a place I found in Florida that could send it to me for only $200. I know someone who will do the work on the side at a really good price.

Any thoughts on buying a used low mile 60K engine instead of doing the rebuild of the original 135K mile engine? Any downside I do not see?

Thanks in advance

[TerryS]

No downside, except you should have NO trouble at all finding a good engine for a third of what you're thinking