Max Cam Lift Before Grind

[NRB26]

Have done a little research and I'm still unsure what the max lift is before you have to grind the lifter walls. Some say 9.15. Some say 9.5. I'd like to know what size cams people have fitted without grinding the head. Are there differences in rb26 heads? The guy that sold me the cams assured me that they were straight drop in.

[The Dan]

Largest I have fit without relieving material was a JUN 9.7mm camshaft

Pretty sure a 10mm may touch, 10.25 definitely will, 9.15 will piss it in

[NRB26]

Some photos of the cams I tried to fit. Wound the engine over by hand and it locked up. Only 9.25mm lift. 32mm base circle and 41.25mm lobe. This was only the exhaust side that I had an issue. Inlet spins freely. Ground lifter walls down to clear lobe. Now OK

Has anyone seen this before?

[The Dan]

Some photos of the cams I tried to fit. Wound the engine over by hand and it locked up. Only 9.25mm lift. 32mm base circle and 41.25mm lobe. This was only the exhaust side that I had an issue. Inlet spins freely. Ground lifter walls down to clear lobe. Now OK

Has anyone seen this before?

Yes, that's because you are using 32 base circle. You need to use reduced base circle for anything over 9.1

[NRB26]

Yes, that's because you are using 32 base circle. You need to use reduced base circle for anything over 9.1

Would that still be considered as "drop in" camshaft?

[The Dan]

Would that still be considered as "drop in" camshaft?

That depends on who makes the camshaft and what they specify it to be.

But anything different than a step1 or type1 for most manufacturers would be considered modified. I don't think any of them do a 9.25 step 1. I'm guessing it's a Tomei?, if that is the case, then 9.15 is the highest 'drop in' they do from memory

Although not sure Tomei even do a 9.25 and cbf looking

[djr81]

That depends on who makes the camshaft and what they specify it to be.

But anything different than a step1 or type1 for most manufacturers would be considered modified. I don't think any of them do a 9.25 step 1. I'm guessing it's a Tomei?, if that is the case, then 9.15 is the highest 'drop in' they do from memory

Although not sure Tomei even do a 9.25 and cbf looking

Yeah they do - 256 degree 9.25 lift inlet & exhaust.

Base circle is 32mm.

Edited March 3, 2011 by djr81

[DiscardTheWeak]

Are tomei procam 260 10.25 drop in when their buckets used?