maddox710 Posted April 24, 2015 Share Posted April 24, 2015 Put the head back together with new exhaust valves in and in really really tight on the tolerance, its booked in for remap again on the 2nd , i need to know if the exhaust will wear into spec or will be okay??? Quote Link to post Share on other sites
5e colin Posted April 24, 2015 Share Posted April 24, 2015 if its within then its ok if its out you will hear a tappy top end amigo Quote Link to post Share on other sites
maddox710 Posted April 24, 2015 Author Share Posted April 24, 2015 Its under and tight but not a fat lot Quote Link to post Share on other sites
5e colin Posted April 24, 2015 Share Posted April 24, 2015 cold or hot ??? if thats cold then u might have valves not sealing right 1s the exhaust valve heats up and extends in lenght Quote Link to post Share on other sites
Phil Posted April 24, 2015 Share Posted April 24, 2015 I thought the tolerances where to be measured cold.?Phil Quote Link to post Share on other sites
morgey Posted April 25, 2015 Share Posted April 25, 2015 If youve changed the valves then the seating will have changed So would quite likely need reshimming. Look through rob H's sr turbo build he ran different specs to recommended so you might get away with it. Quote Link to post Share on other sites
maddox710 Posted April 25, 2015 Author Share Posted April 25, 2015 Yeah because the new valves are all slightly longer than originals in just out of tolerance Think im going to have to scap the ported head Quote Link to post Share on other sites
5e colin Posted April 25, 2015 Share Posted April 25, 2015 are the valves aftermarket ??? or stock if there stock its just a matter of rechimming phill thats best done hot if you set it cold it will be tighter them the spec 1s heated up !!!!!! Quote Link to post Share on other sites
morgey Posted April 25, 2015 Share Posted April 25, 2015 work out how much to thick each one is number each one bag them up and take them to a machine shop. Give them a list of how much needs taking off each one. They will then grind off the required amount off of each one, renumber Them and then you can just wack them straight back in. I could do it in like 20mins at my place so would be like £10-15 max Quote Link to post Share on other sites
maddox710 Posted April 25, 2015 Author Share Posted April 25, 2015 work out how much to thick each one is number each one bag them up and take them to a machine shop. Give them a list of how much needs taking off each one. They will then grind off the required amount off of each one, renumber Them and then you can just wack them straight back in. I could do it in like 20mins at my place so would be like £10-15 max wish it was that easy morgey, I live miles away from any machine shop. Plus it's all abit of a rush job atm arrgg, Quote Link to post Share on other sites
morgey Posted April 25, 2015 Share Posted April 25, 2015 Ahh that sucks the only other way is to measure them and then order the correct thickness ones or raid a scrappy for em. Both are time consuming though unfortunately :/ Quote Link to post Share on other sites
Rob H@RCH Engineering Posted April 25, 2015 Share Posted April 25, 2015 If youve changed the valves then the seating will have changed So would quite likely need reshimming. Look through rob H's sr turbo build he ran different specs to recommended so you might get away with it.I did mine to the toyota book spec but the n/a book but there sod all differance in the turbo spec to the n/a anyway. I would not do them hot tho as you would end up with very sore finges lol and the toyota book says to do them cold too. If there new valves on fresh cut seats they will tend to get tighter as they run in, not much tho if they where well lapped in. I did mine twice once when the enine was on the stand and again after around 1500 miles and most had got a bit tighter if anything. The engineering place that did the cutting and grinding on my valves did recommend setting the clearances after the running in anyway as all it will cause if there a bit tight is slightly lower compression. And theres no chance of contact of the valves anyway. So imo If there not daft tight I would build it up and get it tuned and then fine tune the clearances. But only if there not too tight! What do they measure anyway? Quote Link to post Share on other sites
maddox710 Posted April 25, 2015 Author Share Posted April 25, 2015 Cheers for good feedback rob, I could only get .27 under the exhaust Quote Link to post Share on other sites
Rob H@RCH Engineering Posted April 25, 2015 Share Posted April 25, 2015 That is a bit tight but not a million miles off, exhaust on the n/a should be 0.31 to 0.41 on cold engine and inlet should be 0.15 to 0.25 I think the turbo spec is a bit more but ive been running the N/A specs on mine for years at 230 whp and with cruise cams so it carnt be far out lol Quote Link to post Share on other sites
maddox710 Posted April 25, 2015 Author Share Posted April 25, 2015 They are the same I've checked, dunno what to do now I've got the old head of the car now, might have to just put new springs in ;( Quote Link to post Share on other sites
maddox710 Posted April 25, 2015 Author Share Posted April 25, 2015 Like some sort of divine intervention the shims out of the old head measure in bang on the make the new head work Quote Link to post Share on other sites
Rob H@RCH Engineering Posted April 25, 2015 Share Posted April 25, 2015 😀😀😀👌👌😅 Quote Link to post Share on other sites
maddox710 Posted April 25, 2015 Author Share Posted April 25, 2015 All is good now bar one, is only a slight bit tight Buzzin Quote Link to post Share on other sites
5e colin Posted April 25, 2015 Share Posted April 25, 2015 great news always handy having old shims lying around rob why would you have sore fingers checking clearance when hot ??? no need to touch them with fingers just your feeler gauge ( when hot ) Quote Link to post Share on other sites
Rob H@RCH Engineering Posted April 25, 2015 Share Posted April 25, 2015 I was having a laf! but thinking about it you would still need to take the rocker cover off and stuff with a hot engine so youd still have steaming fingers lol but theres very few engines that you check the clearances on when there hot these days and long gone are the days we used to check them on a running engine HSE would have a heart attack lol Quote Link to post Share on other sites
5e colin Posted April 25, 2015 Share Posted April 25, 2015 yes i know what you mean i learned my engine stuff on the old style push rod blocks always hot on them ha ha my very first car she was a gt turbo to ( r5 ph2 ) Quote Link to post Share on other sites
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