suprasize Posted October 2, 2011 Share Posted October 2, 2011 Okay, so ive been plotting to do a 1jz gte conversion on.my na and want a perfect candidate and think I may have found it until I got back the results of a compression test... the test found that 5/6 cylinders had readings between 0-10% which apparently very good.. =) however, cylinder 5 showed a leak of 40%... Im no mechanic but is that extremely bad or okay? He reckons Its good for a secondhand engine, but how true is that? Im not questioning this guy's ability and hes been so open and informative through this engine hunt.. Should I bite the bullet and take this? Need everyone's thoughts! =) Many Thanks Dan Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 2, 2011 Share Posted October 2, 2011 (edited) 40% leak sounds like it needs stripping to me depending on where its leaking from, could be either valves, piston rings, cylinder bore or head gasket Edited October 3, 2011 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
suprasize Posted October 2, 2011 Author Share Posted October 2, 2011 I can forward the email (my phone wont let me copy and paste) =(. He says it was from the exhaust valve which could either be pitted or a bit of carbon build up that should cure itself? =/ Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 2, 2011 Share Posted October 2, 2011 I think it'll need the head off and re cut the valves and seats, if you do that then you might as well do them all, engines rarely fix themselves. Quote Link to comment Share on other sites More sharing options...
suprasize Posted October 2, 2011 Author Share Posted October 2, 2011 Sounds fair enough ill have a word, if he doesnt then I have got a back up plan =) Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 2, 2011 Share Posted October 2, 2011 Back up plan ? Quote Link to comment Share on other sites More sharing options...
suprasize Posted October 2, 2011 Author Share Posted October 2, 2011 Another engine but not sure if they'll compression test it =( separate company btw haha you recon it's too bad? He said its in a acceptable percentage at 40% but im anal and what the perfect block =) Quote Link to comment Share on other sites More sharing options...
suprasize Posted October 2, 2011 Author Share Posted October 2, 2011 Okay another engine has came up 80,000kms from.an.auto, compression test came back 175psi across the board, is that more reasonable? =/ Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 2, 2011 Share Posted October 2, 2011 Who are you looking at buying these engines from ? i'd tread very carefully unless your there watching the test being done, very few engines have the same on each cylinder. If its true though 175 on all 6 is good Quote Link to comment Share on other sites More sharing options...
suprasize Posted October 2, 2011 Author Share Posted October 2, 2011 Thats good =) that one was on a private for sale thread on driftworks, the other with the 40% leak was from nickson motorsport off DWs webby aswell, I know what you mean though just want to find a perfect candidate for.my conversion =( everything is so expensive though =( Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted October 2, 2011 Share Posted October 2, 2011 Define expensive? Maybe if its expensive you shouldnt be looking to convert? Just saying, devils advocate and all that. 175 across the board is good for compression, there is a bottom limit but the difference between the cylinders is the key thing. Quote Link to comment Share on other sites More sharing options...
Guigsy Posted October 2, 2011 Share Posted October 2, 2011 My single had about 50psi on one cylinder when I got it. A bit of oil in it and after a while it slowly came good. Quote Link to comment Share on other sites More sharing options...
Yakky Posted October 3, 2011 Share Posted October 3, 2011 Do the compression test yourself, or else get a second opinion from another garage first. Get the cylinder number that has "failed". Be cynical first mate. Quote Link to comment Share on other sites More sharing options...
suprasize Posted October 3, 2011 Author Share Posted October 3, 2011 Okay, ive a had a bit of joy on the first engine. Apparantlythis test wasn't a compression test but a leak down test whereby a constant pressure of 100psi is passed through the cylinders constantly whilst all valves are closed. Thks should show any leaks including piston rings etc There was no leaks through the piston rings to the crank cawe whatsoever it was a leak on one valve out of 24 which apparently is very good, hes going to leak down test the other engine for me but strongly doubts itll have as good a compression as this one. He did say he would remove the head but it's an additional ,l £100 for the parts as well as a days labour to remove the head and work.on valves. Quote Link to comment Share on other sites More sharing options...
Dnk Posted October 3, 2011 Share Posted October 3, 2011 Spend the money and get the head off and re cut the seats and valves would be my suggestion if thats where its leaking from. Quote Link to comment Share on other sites More sharing options...
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