Frax Posted June 20, 2011 Share Posted June 20, 2011 Got a new head gasket today and proceeded to remove the head. All went well – head removed and given a good clean. When I unpacked the new gasket I found that it was metal plate which sandwiched some other material. I have now put it on and replaced the head but not torque it up as yet. Are they normally metal ? Does a metal to alloy give a good seal – just seems strange to me but I have not done one of these before. Regards Frax Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 20, 2011 Share Posted June 20, 2011 You have got what is known as an MLS gasket (Multi-Layer Shim steel). By far better than the composite type, but the mating surfaces have to be near-perfect. Les. Quote Link to comment Share on other sites More sharing options...
Frax Posted June 20, 2011 Author Share Posted June 20, 2011 Thank you Les. Frax Quote Link to comment Share on other sites More sharing options...
Boydie Posted June 21, 2011 Share Posted June 21, 2011 A word of caution, use NEW head bolts, discard the old ones! The degree method of torque settings is designed to stretch the head bolts - and they dont take too kindly to being stretched a second or even third time, my bitter experience is that they will be soft and the head gasket will fail! Quote Link to comment Share on other sites More sharing options...
Frax Posted June 21, 2011 Author Share Posted June 21, 2011 Hi I did check the rav manual and it said that the that the bolts can be used upto 5. I do not know how many times the head has been done before but it has 117k on it. Has anyone else had the same problems. Regards Frax Quote Link to comment Share on other sites More sharing options...
Boydie Posted June 22, 2011 Share Posted June 22, 2011 Yeah, I read that too in my works manual, and I knew my bolts were the original and had done 230,000 kilometers before the head had to come off due to a shot valve and the experience cost me a AUD$200 head gasket, a cylinder head and an expensive tow 100 kilometers home. Given that can be the cost of head bolt failures I think the cost of a replacement set at around AUD$80.00 is money well invested. A question here, a paternmaker pal of mine who has access to a quality foundry is willing to cast me a steel cylinder head with improved waterways, the idea being to port the steel head to match the cylinder block waterways between the cylinders that are closed off by the alloy head. Given that the cost of a "Generation 2" alloy cylinder head is around AUD$1250.00 (and cannot be machined)and the steel one he is proposing will cost the same are there any interested parties? The head would be drilled and machined and valve guides and seats fitted but the valve sets would need to be transfered from your existing head and lapped in and new valve seals fitted, a "guestimate" of the additional weight is around 9 kilos over and above the alloy unit. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 22, 2011 Share Posted June 22, 2011 It's a bit unlikely that the head has been off 4-times in that kind of mileage (but you never know ) A new set isn't that expensive - £20-odd quid I think. Les. Quote Link to comment Share on other sites More sharing options...
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