Bishopsrock Posted June 20, 2006 Share Posted June 20, 2006 I am off to buy my second R33 RB26DETT motor tomorrow. The first one (although running) turned out to have a cracked head so second time lucky for me - I hope! I want to do a compression test on the new engine but don't know what figures I should consider to be a pass and what the threshold for a fail should be. Please can anyone help? With thanks in anticipation Quote Link to comment Share on other sites More sharing options...
turbo_fb Posted June 20, 2006 Share Posted June 20, 2006 It was mentioned in a post just a few lines below your thread. http://forums.hybridz.org/showthread.php?t=111956 Quote Link to comment Share on other sites More sharing options...
Bishopsrock Posted June 20, 2006 Author Share Posted June 20, 2006 Hi thanks for responding, I read that post but I still dont have a guide as to what I should consider a pass and what is considered a fail? If my second hand engine comes out at the same figures as the RB manual says then great - but I somehow very much doubt that it will. Im gonna have to make a decision on the spot with a lot of cash at stake and so any further guidance would be appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
BirdmanZ Posted June 21, 2006 Share Posted June 21, 2006 standard value: 171 psi @ 300 rpm limit value: 128 psi @ 300 rpm Limit value is the lowest acceptable result. If it makes less than that then it needs work. Quote Link to comment Share on other sites More sharing options...
Bishopsrock Posted June 21, 2006 Author Share Posted June 21, 2006 Thanks Birdman Z. I will post the results with the stated engine mileage when I get back tomorrow. Quote Link to comment Share on other sites More sharing options...
Bishopsrock Posted June 27, 2006 Author Share Posted June 27, 2006 Ok here are the results. The engine had a damaged radiator and broken intercooler so it was only fired up for two minutes to demonstrate that it worked. I removed all plugs and got the following readings on a battery crank without depressing the accelerator. Taking the cylinder closest to the engine fan as No 1. 1 - 150 2 - 150 3 - 140 (148 at second attempt after re-tightening the tester) 4 - 148 5 - 148 6 - 148 Does anyone know if this small amount of difference in compression between the sets of cylinders is anything to worry about? or why it happens? The engine was said to have convered 52,616 Kilometers. I checked the gauges and there was no sign of the instrument cluster having been opened or tampered with! Thanks Quote Link to comment Share on other sites More sharing options...
BirdmanZ Posted June 27, 2006 Share Posted June 27, 2006 The service manual allows a variance of 14 psi between cylinders so i would not worry about 2 psi. Test figures look very good. Also, IIRC you are supposed to have the throttle open while doing a compression test so the figures you got may be lower than what it really has. Either way looks to be a healthy engine. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted June 27, 2006 Share Posted June 27, 2006 Man I want one sooo bad I can taste it. Quote Link to comment Share on other sites More sharing options...
BirdmanZ Posted June 27, 2006 Share Posted June 27, 2006 You and me both. Bishop, how much is that r33 engine? Quote Link to comment Share on other sites More sharing options...
Bishopsrock Posted June 27, 2006 Author Share Posted June 27, 2006 Hi Birdman z Thanks for the re-assurance. I have high hopes for this engine. I bought it from a UK specialist supplier of complete JDM engines for transplant. It cost £2,475 GBP for everything under the bonnet that I wanted including the loom and ecu. The reason I bought a second engine is purely down to time. Its summer here right now but there is only 3 months of this left and i want to drive my car. I am twin tracking the rebuild of the head on my first engine and will soon have a complete engine to sell for transplant myself and so hopefully recover most of the cost. I think that anyone buying one of these engines absolutely must check the radiator for signs of emulsified oil and also do a compression test to identify any signs of failure in the head hasket due to warping or any alarming compression differences between cylinders. I will of course post my impressions of the engine once its running. Thanks Quote Link to comment Share on other sites More sharing options...
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