4age camtech 272 8.6mm bucket under shim conversion.. or not?

[crunk81us]

Hi All I am new here,
Car is a Ke20 that my brother and i converted to efi 4age smallport.

have camtech 272 8.6mm cams coming, as well as performance springs.

I already have adjustable cam sprockets and silvertop itb.

going to be sending a spare head off for a quick port and polish and will have them assemble the head with the cams and springs..

I am trying to keep costs down and wondering if i can get away without shim under bucket mod, or if its just not worth the risk.

anyone run 8.6mm or more here on standard shims?

[Jimmee1990]

Generally 8.3mm is considered pretty close to the limit, but it depends on the ramp rate also. It would definitely be worth doing really, considering the head is all apart already also.

[crunk81us]

Thanks jimmee, I guess if it's costing me 2k+ another couple hundred doesn't make too much difference..

[Sam-Q]

I would of thought that 8.3mm would have loads of room to spare? I tried 9mm of lift in a cam of which I slowly turned it over and found it missed the edge of the shim no problem. I can se there being any issue at all, however I can supply some buckets for you if you want them

[crunk81us]

so maybe i should trial fit and have a look first.. theres no big rush on this so i dont mind if i find out i need under buckets and it takes another month..

[crunk81us]

Anyone know at what lift the 4 age becomes an interference engine?