Faiyaz.123 Posted November 11, 2017 Author Share Posted November 11, 2017 (edited) Need some info I've tried looking it up .but can' seem to get a spot on answer. I have 74.5mm wiseco pistons with scat rods and head work done including Billet camshafts 8.8-9.0mm lift and 272 degrees duration im trying to do a compression test and my results are showing 8.1 which is about 125 psi across all cylinders Abit puzzled where I'm going wrong any help would be highly appreciated Edited November 11, 2017 by Faiyaz.123 Quote Link to post Share on other sites
maddox710 Posted November 11, 2017 Share Posted November 11, 2017 8 minutes ago, Faiyaz.123 said: Need some info I've tried looking it up .but can' seem to get a spot on answer. I have 74.5mm wiseco pistons with scat rods and head work done including Billet camshafts 8.8-9.0mm lift and 272 degrees duration im trying to do a compression test and my results are showing 8.1 which is about 125 psi across all cylinders Abit puzzled where I'm going wrong any help would be highly appreciated What material had been took off the head then? Quote Link to post Share on other sites
Faiyaz.123 Posted November 11, 2017 Author Share Posted November 11, 2017 1 minute ago, maddox710 said: What material had been took off the head then? Assuming you want this info Full race spec head (extended port and polish, faced, valve seated and shimmed, including): Uprated Valve Seals Uprated Valve Springs (suitable for high lift billet cams) Uprated Valve retainers Solid buckets with lash caps, and shimmed Billet camshafts 8.8-9.0mm lift and 272 degrees duration This was all done by zisco. Also the compression test we done was with engine warm . What doesn' make sense to me is if they was something wrong then why get the exact same figure across all cylinders .We just doing some test before changing the tune. Quote Link to post Share on other sites
maddox710 Posted November 11, 2017 Share Posted November 11, 2017 Well if they'e taken meat out the combustion chamber on the heat then effectively they have decreased the compression ratio by increased the space the cylinder has to squeeze the mixture Quote Link to post Share on other sites
Faiyaz.123 Posted November 11, 2017 Author Share Posted November 11, 2017 1 hour ago, maddox710 said: . Quote Link to post Share on other sites
Faiyaz.123 Posted November 11, 2017 Author Share Posted November 11, 2017 Sorry bout that don't know what happen with that reply . Ok so this means it' fine to have the trading I have now ? Quote Link to post Share on other sites
Faiyaz.123 Posted November 11, 2017 Author Share Posted November 11, 2017 1 hour ago, maddox710 said: Well if they'e taken meat out the combustion chamber on the heat then effectively they have decreased the compression ratio by increased the space the cylinder has to squeeze the mixture Sorry bout that don't know what happen with that reply . Ok so this means it' fine to have the trading I have now? Quote Link to post Share on other sites
maddox710 Posted November 11, 2017 Share Posted November 11, 2017 You could use a smaller headgasket, or skim head and block and used domed pistons. Obviously all clearance need to be checked before hand Quote Link to post Share on other sites
daniel_g Posted November 11, 2017 Share Posted November 11, 2017 Are you using the 9.1cr wiseco pistons? Quote Link to post Share on other sites
Flower Posted November 12, 2017 Share Posted November 12, 2017 On 11/11/2017 09:24:00, Faiyaz.123 said: Need some info I've tried looking it up .but can' seem to get a spot on answer. I have 74.5mm wiseco pistons with scat rods and head work done including Billet camshafts 8.8-9.0mm lift and 272 degrees duration im trying to do a compression test and my results are showing 8.1 which is about 125 psi across all cylinders Abit puzzled where I'm going wrong any help would be highly appreciated As previously said. Work on combustion chambers will affect C:R as well as HG thickness etc. To reduce the C:R you could use a thinner HG, skim the block or head. I have read somewhere before (maybe corky's engine tuning book) that if uprated/different spec cams have a lot of over lash this will affect static compression due to the scavenging affect of the cams. I'm not saying this why but could be a possibility ? Quote Link to post Share on other sites
Faiyaz.123 Posted November 16, 2017 Author Share Posted November 16, 2017 On 11/12/2017, 2:36:17, Flower said: As previously said. Work on combustion chambers will affect C:R as well as HG thickness etc. To reduce the C:R you could use a thinner HG, skim the block or head. I have read somewhere before (maybe corky's engine tuning book) that if uprated/different spec cams have a lot of over lash this will affect static compression due to the scavenging affect of the cams. I'm not saying this why but could be a possibility ? I agree to this it makes sense we have gone over it and have found no bad effect besides lag and cr but motor is still health and going higher. Thank you for all the inputs .now back to stressing about gearbox Quote Link to post Share on other sites
Faiyaz.123 Posted July 17, 2020 Author Share Posted July 17, 2020 (edited) So maybe it's time a update this . After my fall down with my previous 4efte engine bending the crank (don't know how) I've gone 5e will post some pics currently running .I've stopped at 1bar of boost and rev limit at 8krpm .gearbox doesn't seem like to like it but yeah we know there's no alternative to it hence why I lost interest in it. I've gone side exit its fun even though the person stuck it out the bumper instead of it sitting flush . Currently trying to figure out out why my p/s belt keeps splitting its a 4efte p/s am I using the wrong length or is there a spacer to be added. Help would be appreciated. I think this is my stopping point before I ended selling or stripping. VID-20200628-WA0006.mp4 Edited July 17, 2020 by Faiyaz.123 Quote Link to post Share on other sites
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