Lotus Elan Central

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

by **paulwatkins** » Fri 13.04.2007, 09:14

Doc,
The issue here is that the head gasket supplied as part of kmc's kit is DIFFERENT to the Lotus branded head gasket.

I dont think the gasket set that kmc supplies may be an Isuzu branded set.

I had one of each, a kmc and a lotus gasket side by side, to compare during my engine rebuild and they not only look different (as can be seen in the picture above) but also feel different and are obviously made form different materials.

The fact that you either have to remove the insert in the kmc gasket or the dowel in the block clearly demonstrates this.

Paul

I am reading this thread with interest because I decided to go with the lotus branded gasket in the end - because of the dowel/insert issue - even though the kmc gasket appeared to be a 'better' looking item. I am going to recheck the torque of my head bolts and I am extremely interested in what I will find!

by **Doc Fizzix** » Fri 13.04.2007, 15:33

paulwatkins wrote:The issue here is that the head gasket supplied as part of kmc's kit is DIFFERENT to the Lotus branded head gasket.

I was just answer the comment that the heads ar different (different pins) and I know this is not the case, they are the same. Also, since I did my work I know the gasket sets from Isuzu and Lotus are the same thing.

It sounds like who ever made the kmc gasket made an error with one of the pin holes because I bet the Isuzu users have to also remove the same piece to get thegasket to fit.

by **Monty** » Fri 13.04.2007, 15:36

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

Geoff, u never talk Bollocks mate, i was just worried that removing that insert would weaken that section and just thought it wasn`t worth risking. But looks like it`s a ok to remove according to Kmc :roll:

I do question why the headgasket was reproduced since the Isuzu ones seem cheap

Think i`ll stick to the Lotus/Isuzu type in the future

by **paulwatkins** » Fri 13.04.2007, 20:38

I'm glad to say that upon checking the head bolts on mine, they were still set correct (this was with the Lotus brand gasket) at 78Nm.

Only problem was the effin leads coming apart in my hands....even when knowing about the problems and trying to grip down low! :evil:

Luckily I kept the old set and refitted them. I will have to order up a new set and replace another time. But for now, happy motoring again, and worry free! For now!

Cheers, Paul

by **kmckmc** » Sat 14.04.2007, 23:14

Hi,

I talked to the vendor of those gasket sets earlier today and asked him if there will be any negative consequence associated with removing the cooper washer/insert from the head gasket. He said it does not matter at all; it is okay to remove the washer/insert. The head gasket will not be weaken due to this washer/insert removal.

In the future he will remove those washer/insert before he packages these gasket sets.

Cheers,

by **lotuska** » Sat 21.04.2007, 19:27

Right, had last weekend off, my 40th birthday...welcome cheaper insurance.

Anyway, I've been doing some more work today and part of this has been a little more work looking at the head gaskets and I've come up with some issues.

Firstly I checked the thickness of each head gasket using my trusty micrometer...

Thickness of gasket material
- Lotus Original 1.22mm
- kmckmcs replacement 1.65mm

Thickness of "metal" bits around cylinders etc
- Lotus Original 1.35mm
- kmckmcs replacement 1.75mm

I've also been taking a closer look at the area where my original gasket (lotus original) failed, this was on No.1 cylinder, between the piston and water jacket.

I've noticed that the Lotus original gasket seems to have some voids (or gaps) for lack of a better term at various points around the gasket. These appear to be in the layers of the gasket material itself, picture below might help (Lotus original is all grey, kmckmc gasket is the one with yellow in it.

It also appears that the lotus gasket has been "crushed" in lots of places. Difficult to explain this but where there are holes or the metal reinforcements the gasket looks depressed and almost cracked, picture below might help explain.

Anyway I decided to use kmckmc's gasket, I removed the metal insert that was preventing the gasket fitting over the dowel and it now fits perfectly.

by **lotuska** » Wed 25.04.2007, 20:51

More project creep.....

by **lotuska** » Sun 29.04.2007, 20:52

Moving along I've now been working on the hydraulic valves, taken some pictures and a bit of video, don't know if its of any use to anyone....

by **Monty** » Sun 29.04.2007, 23:14

Great vids Mark, I`m sure they`ll come in handy for many people.

BTW, on the head gasket, IMHO i`d stick to the Lotus/Isuzu gasket

Lotus Elan Central

Valve Stem Oil Seal Replacement

Who is online