Lotus Elan Central

by **lotuska** » Mon 09.04.2007, 12:04

A quick question about the head gasket.

Both the old and new gaskets have a couple of circular holes for water but the holes both in the head and block are nothing like circular. Also looking at the old gasket its obvious that there has been quite a build up of crud around these.

Is it possible to enlarge the holes to match the block & head? and could there be any issues doing this?

A couple of pics might explain. The holes I'm wondering about are between the 2 head bolt holes, kind of triangular in shape.

by **lotuska** » Mon 09.04.2007, 13:42

Hit a problem...

The gasket set that I got from kmckmc doesn't seem to fit.

2 problems, firstly the gasket won't fit over one of the dowels and secondly it has a hole missing that the original has.

Any ideas?

by **GeoffSmith** » Mon 09.04.2007, 15:02

'kinell Mark. I've just checked my gasket and it's the same.

Check out the Stripey II thread - Monty had identified the circular vs. triangular holes so enlarged the holes but he did not report the lack of holes! As well as pressurising the cooling system, he's also suffering from water in the pots. I suspect that the lack of gasket hole may be to blame!

Geoff

EDIT: is there a hole missing from both gaskets in the same position on the top cylinder?

by **GeoffSmith** » Mon 09.04.2007, 15:05

Is the build up in crud on the old gasket because the hole in the head is circular?

by **Monty** » Mon 09.04.2007, 15:43

Mark,

I enlarged the holes in Kmckmc`s head gasket buy laying the gasket on to the block and used a stanley knife.

On u`r last photo i never noticed that hole missing on the gasket :shock:

is that a water passage or the head bolt hole?

Could explain why i had temp and pressure problems on track :roll:

and nother thing i`ve noticed that the original gasket seemd to have more of re-enforcing built in

To be on the safe side go for the Lotus one there about £25

ps i had to remove the locating dowel to fit Kmckmc gasket

by **lotuska** » Mon 09.04.2007, 16:02

The missing hole is a water one, I have also noticed that the original lotus gasket has much more re-enforcement around the various holes.

After all of my work I think I'll go safe and get a Lotus one, hopefully PM will have one in stock.

by **Monty** » Mon 09.04.2007, 16:19

lotuska wrote:The missing hole is a water one, I have also noticed that the original lotus gasket has much more re-enforcement around the various holes.

After all of my work I think I'll go safe and get a Lotus one, hopefully PM will have one in stock.

arrhhhhhhhhh for Fook sake, so that could be the cause of my problems :twisted:

and i bet i`ve damaged the head to top it off :roll:

by **GeoffSmith** » Mon 09.04.2007, 16:31

geoffsmith wrote:Is there a hole missing from both gaskets in the same position on the top cylinder?

geoffsmith wrote:Is the build up in crud on the old gasket because the hole in the head is circular?

by **Monty** » Mon 09.04.2007, 16:42

geoffsmith wrote:
geoffsmith wrote:Is there a hole missing from both gaskets in the same position on the top cylinder?

geoffsmith wrote:Is the build up in crud on the old gasket because the hole in the head is circular?

Looks like geoff is right on the bottom photo the hole below the locating dowel is missing on both gaskets

what the hell is going on with these gaskets :roll:

Mark, could u compare both gaskets to the head rather than the block?

Geoff on u`r 2nd question, think thats just wear the original gasket is just wearing through as the holes are small like the kmckmc one

by **lotuska** » Mon 09.04.2007, 19:13

Right, good news on the gasket issue...

I've taken pictures of the head, block, new gasket & old gasket and checked off all of the holes.

Colour coded them as:
Yellow - Bolts holes
Green - water holes
Blue - oil holes
Pink - the missing hole on the new gasket
Red - holes that are in either the new & old gasket or block

The important bit is that there are no missing or blocked holes going to the head - therefore should be ok.

Sorry Monty doesn't look like this is the cause of your problems.

by **lotuska** » Thu 12.04.2007, 14:32

Right I've managed to "borrow" a Lotus genuine head gasket and I've compared the holes etc....good news is that the new one has no additional holes and matches the one kmckmc has been suppling exactly (in terms of the holes).

There are differences...

1. Hole in the bottom left where a head bolt passes and one of the 2 dowels is - this is larger on the lotus one so that it will fit over the dowel.
2. several holes on both gaskets have metal or plastic type rings round them - they are on some different holes on each, whether this makes a difference I don't know.

by **GeoffSmith** » Thu 12.04.2007, 17:53

Mark,

Could you measure the diameter of the locating dowel holes on the two gaskets, to see how close the kmckmc one is?

Geoff

by **dapinky** » Thu 12.04.2007, 18:56

Geoff,

There's no need to do any measuring.

If you look closely at the picture, you will see that the actual gasket has the same cut-outs - but the kmc one has a metal insert (like a copper washer) in that hole.
This can be pushed out of the gasket, leading to the same fit as the genuine one.

I had the same issue with the one i used (NOT from kmc, but from USA, destined for an impulse turbo). i can only assume that Lotus used a slightly different head locating dowel system than Isuzu, but it can be used if you modify it. The insert pushed out with finger pressure easily.

by **GeoffSmith** » Thu 12.04.2007, 19:01

dapinky wrote:The insert pushed out with finger pressure easily.

by **Monty** » Thu 12.04.2007, 19:45

Don`t think i would recommend removing the metal ring as it`s very close to another hole only IMHO, i removed the locating dowel on that side. It`s wierd that one locating hole fits but the other doesn`t

by **GeoffSmith** » Thu 12.04.2007, 20:41

Monty wrote:Don't think i would recommend removing the metal ring as it's very close to another hole only IMHO, i removed the locating dowel on that side. It's wierd that one locating hole fits but the other doesn't

If you check out Mark's colour coding, it's only a bolt hole next to it and there is a seal around both so I don't think it's a problem. Like you, I was sceptical but yet again Pinky is right!

by **Monty** » Thu 12.04.2007, 22:52

geoffsmith wrote:
Monty wrote:Don't think i would recommend removing the metal ring as it's very close to another hole only IMHO, i removed the locating dowel on that side. It's wierd that one locating hole fits but the other doesn't

If you check out Mark's colour coding, it's only a bolt hole next to it and there is a seal around both so I don't think it's a problem. Like you, I was sceptical but yet again Pinky is right!

Sorry, but i`m not with that one. I`ve had the gasket and the gasket between the two holes is very narrow which is why went against removing the insert. Don`t think it`ll be a good idea getting the hot coolant to the head bolt (thats if u can keep coolant in the head to start with lol). More than likely the one Lotus sell is made different using different materials and does not need the insert

Thats why i`ve ordered the lotus version

by **GeoffSmith** » Thu 12.04.2007, 23:02

Think you're right Monty. I was talking bollocks. :oops:

by **kmckmc** » Fri 13.04.2007, 02:57

Hi guys,

Many people have spent time discussing about head gasket in the past few days. I am glad to know that the head gaskets I supplied to other LEC members are almost identical to that of the Lotus/Isuzu ones. I use the same head gasket on my engine. It is fine. 2500km thus far. I believe my mechanic took out the dowel.

The vendor who supplied these gasket sets to me sells these sets to Japan and Africa. These gaskets are for Isuzu Impulse Turbo. I did inform him the LOWER LEFT cooper washer/insert issue. He assures me that either taking out that washer/insert or removing the dowel in that place is FINE. He said that no one ever mentioned this issue to him. Well, no other Elan M100 drivers had approached him previously... In the end, he agrees to remove that LOWER LEFT washer/insert out of the head gasket before he packages the set in the future. This vendor also sells head gasket in different THICKNESS. whoever is interested could contact me.

These gasket sets are not ISUZU branded; they are generic gasket sets designed specifically for ISUZU IMPULSE TURBO.

If people have questions, please contact me.

Cheers,

by **Doc Fizzix** » Fri 13.04.2007, 04:00

dapinky wrote:I had the same issue with the one i used (NOT from kmc, but from USA, destined for an impulse turbo). i can only assume that Lotus used a slightly different head locating dowel system than Isuzu,

The answer ---- NO! (they are the same)

The block and head are basicly the same in every way. I even bought the Isuzu Turbo gasket set in order to compair the Isuzu gaskets with the Lotus set during my Hot-to-trot motor rebuild. Both gasket sets are the same in every way including the head gasket, Lotus does not use its own set, they just use the same Isusu gaskets. The only difference between the two gasket sets was that Lotus put a "Lotus" sticker on the Isuzu gasket set box.

http://www.lotuselancentral.com/forum/v ... php?t=5564

and

http://www.lotuselancentral.com/forum/v ... c&start=40

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