Shane Posted September 30, 2015 Share Posted September 30, 2015 So, with a MLS, what's to stop you using the SS middle layer from one gasket and add it to another so you end up with a 4 layer instead of a 3 layer and have the ability to create gaskets of varying thickness? My understanding of it is that its the top and bottom layers that are the all important parts with their layer of rubber and embossing. Had a read through this http://www.cometic.com/technical.aspx and this http://www.hotrod.com/how-to/engine/ctrp-1108-racing-head-gaskets/ Is there some magic formula or property that would make this beyond the scope of a diyer that I am not seeing? Surely as the middle layer of a 3 layer MLS is a flat sheet of pressed out steel, another identical layer could be added? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 30, 2015 Share Posted September 30, 2015 It can be done, and I have done it, although the resulting sandwich may not be as robust as a 3 layer with a suitably thicker stainless mid layer. Mr Rob Barker at Cometic UK will arrange custom gaskets, and as they presumably have the dies for the 2JZ gaskets it probably wouldn't be *THAT* expensive. The last number I have for Rob is 01255850020 or 07860544751, but I have not had cause to speak to "The Boss Man" for some time. Quote Link to comment Share on other sites More sharing options...
Shane Posted September 30, 2015 Author Share Posted September 30, 2015 It can be done, and I have done it, although the resulting sandwich may not be as robust as a 3 layer with a suitably thicker stainless mid layer. Mr Rob Barker at Cometic UK will arrange custom gaskets, and as they presumably have the dies for the 2JZ gaskets it probably wouldn't be *THAT* expensive. The last number I have for Rob is 01255850020 or 07860544751, but I have not had cause to speak to "The Boss Man" for some time. Thanks Chris, in fact what I have in mind isn't for a change relating to a 2jz, but a 3J Kia engine, a 4 pot 2.9 common rail TD. I have a head away for pressure testing and skimming. One source is telling me that if I skim the head (and I suspect its already had one in its life) then the valve seats need to be cut back by at least the same amount to stop the valves hitting the pistons. Looking at the head I can believe that. The engineering shop are saying it's possible but highly unlikely that a 4-8 thou skim will cause such an issue and also pointed out that if the seats are cut I may well have issues with the valve gap clearance and lifters, a valid point. Conflicting views and as I have 2 head gaskets here I got thinking that a simple fix to get over this on what is meant to be an absolute budget build is to make my own thicker gasket and to leave the valve seats as they are. Looking at the top of the pistons, I would say its pretty close anyhow with the cut outs for the valves. The head face: The pistons can be seen if you click on the image and zoom: Thanks for the details, although for this piece of Korean rubbish I wont be getting your contact to make me one up. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 30, 2015 Share Posted September 30, 2015 It should be fairly trivial to measure valve to piston clearance with the old gasket in place now, and work out what could come off the head. I would say 20 to 25 thou inch valve to piston clearance is the least I would want to see. You could just run two gaskets and chance it. Pocketing the valves is not a good idea, flow will be badly compromised. You may be able to grind the valve tips to keep clearances as stock depending on how much protrusion exists above the top hats and collets and the shim type, assuming it's an OHC engine. I am not familiar with it I am afraid. HTH. Quote Link to comment Share on other sites More sharing options...
Shane Posted September 30, 2015 Author Share Posted September 30, 2015 Thanks Chris. The head is away now for testing and works so not got that to hand to measure. Yes its DOHC I believe in this case it stands for Double Obnoxious Heap of Crap. And yes I wasn't keen on the idea of setting the valves further into the head and the engineering guy certainly wasn't. Also this would probably cost more than the car is worth together with the pressure testing, clean and skim. This was meant to be a quick head gasket change and cheap on the road motor, but costs are quickly stacking up. The original source of the info said that the collision takes place around the 3500 rpm mark, but that doesn't make sense to me, surely it collides or not. Thanks for the input, appreciated. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 30, 2015 Share Posted September 30, 2015 Clash may occur if it's revved high enough for rod stretch or valve float, but I doubt it will get into that heady RpM range Carbon build up may close down clearances too.You could pocket the pistons, but then that's a full engine strip and a lot of setting up of the pistons on a milling machine. More expense still.... Quote Link to comment Share on other sites More sharing options...
Shane Posted September 30, 2015 Author Share Posted September 30, 2015 Clash may occur if it's revved high enough for rod stretch or valve float, but I doubt it will get into that heady RpM range Carbon build up may close down clearances too.You could pocket the pistons, but then that's a full engine strip and a lot of setting up of the pistons on a milling machine. More expense still.... Thanks. No it won't be an engine strip on this. Think i will wait to see if it even passes a pressure test and if it does find out just how much they need to skim it and then go from here. I have found a complete head, cams and rockers etc from a running engine for 150 so that's plan b. I didn't want the bloody thing anyhow, the missus convinced me it was just the thing to fix up and leave in Romania at the house we have bought. She reckoned it was ideal with its 7 seats for when the family came to visit....... I think a moped woiuld have been better so they couldn't visit. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 30, 2015 Share Posted September 30, 2015 I suggest you abandon it here and now and claim it uneconomically repairable, and give her a workshop manual in case she doubts your words You have my sincere sympathy! Quote Link to comment Share on other sites More sharing options...
Shane Posted October 7, 2015 Author Share Posted October 7, 2015 Well its been a long week, late evenings after work and all of last weekend.....but it runs. The head passed the pressure test and they took 8 thou off. The machine shop guy was quite confident it wouldn't collide but couldn't guarantee it without seeing the engine, but others who know this engine said it would be an issue. I was quoted another 140 quid on top of the cost if i wanted them to sink the valves by 8 thou, so Ii decided to modify the head gasket. The head after skim The donor gasket that the extra layer was taken from Around 6 thou All the layers New water pump while I was at it Going back together So its back together and runs, sounds nice and not pressurising the water system now. Had it running for an hour or so earlier and it seems fine. The real test will be when I take it out and pout it under some real load I guess, need to do the rear brakes this weekend and then get an mot on it Quote Link to comment Share on other sites More sharing options...
Benjy Posted October 7, 2015 Share Posted October 7, 2015 Just keep the revs low and the pistons and valves will never meet lol Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 7, 2015 Share Posted October 7, 2015 Nice job, so did you buy 2 gaskets and make one thicker one? Quote Link to comment Share on other sites More sharing options...
Shane Posted October 7, 2015 Author Share Posted October 7, 2015 Nice job, so did you buy 2 gaskets and make one thicker one? Yes, £40 a go but felt it was the sensible thing to do. Almost forgot this Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 7, 2015 Share Posted October 7, 2015 What a stirring noise. Pun intended Looks like a joy to work upon! Quote Link to comment Share on other sites More sharing options...
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