I've fitted a 2.7 that was built using a 325 block, eta crank etc. I has a fast road cam but sadly I don't know what spec? The dyno sheet that came with it shows 198bhp @ 5400 and 202ft/lbs torque.
This was running a bastardized k-jet / motronic mix which is being binned in favour of MAF etc and live re-map.
My question concerns a vernier and whether I should fit one? If so, what benefit should I see? I am on a tight budget so need to know things are going to work before I spend out on them.
Vernier m20
Moderator: martauto
if that is your setup then you would need a vernier. because the face of the lower block would have been decked (cut down basically so the pistons are level) bringing the crank pulley and cam pulley closer (approx half a tooth)
No problemo mate. For others that dont fully understand,
A Vernier camshaft pulley replaces the original unit. however it has adjustment on it to alter the camshaft in correlation to the crankshaft.
A mix and match 2.7 setup needs a vernier because during the process of the engine build, the top of the block (where the headgasket goes) needs to be trimmed down because the pistons do not reach the top and they need to.
Once the top has been trimmed and all built up, the belt under tension makes the upper pulley (camshaft sprocket) approx half a tooth out which does make a difference though you may not think it.
the easiest quick way to get the camshaft on zero (the timing mark lined up) is to fit the original camshaft pulley and set it to the timing mark, then carefully remove it without jolting the camshaft itself. put it to the vernier and level it up. nip one bolt to secure it. then fit the vernier to the camshaft, and check your timing mark is correct and tighten the main centre bolt up. then when you put the belt on, loosen the small bolt you nipped up earlier so currently the vernier is in "adjustment mode" again, make sure the cam hasnt turned. tension up the belt fully, then secure all of the verniers fasteners.
one thing to do though, is when you are in "adjustment mode" turn the outer face only (which should move by your finger tips, fulley clockwise. so when the belt tension is applied, the vernier can adjust without hitting the maximum stop and forcing the camshaft back. if this happens all the above steps have to be repeated.
this way will set your timing up to near enough spot on but minute adjustments may have to be done to get the best out of it, on modified cams, apparently 0-2 degrees advance is optimum I THINK!
hope this helps those when the search function is used!
A Vernier camshaft pulley replaces the original unit. however it has adjustment on it to alter the camshaft in correlation to the crankshaft.
A mix and match 2.7 setup needs a vernier because during the process of the engine build, the top of the block (where the headgasket goes) needs to be trimmed down because the pistons do not reach the top and they need to.
Once the top has been trimmed and all built up, the belt under tension makes the upper pulley (camshaft sprocket) approx half a tooth out which does make a difference though you may not think it.
the easiest quick way to get the camshaft on zero (the timing mark lined up) is to fit the original camshaft pulley and set it to the timing mark, then carefully remove it without jolting the camshaft itself. put it to the vernier and level it up. nip one bolt to secure it. then fit the vernier to the camshaft, and check your timing mark is correct and tighten the main centre bolt up. then when you put the belt on, loosen the small bolt you nipped up earlier so currently the vernier is in "adjustment mode" again, make sure the cam hasnt turned. tension up the belt fully, then secure all of the verniers fasteners.
one thing to do though, is when you are in "adjustment mode" turn the outer face only (which should move by your finger tips, fulley clockwise. so when the belt tension is applied, the vernier can adjust without hitting the maximum stop and forcing the camshaft back. if this happens all the above steps have to be repeated.
this way will set your timing up to near enough spot on but minute adjustments may have to be done to get the best out of it, on modified cams, apparently 0-2 degrees advance is optimum I THINK!
hope this helps those when the search function is used!
My engine was making 198bhp without the vernier but will be doing another power run once fitted and timed up as required. Hopefully, combined with 6 branch, filter etc, I'll break 210.
Thanks again for your help and I'll post the dyno sheet up here.
Thanks again for your help and I'll post the dyno sheet up here.
