[stevros]

Hi, im running a rb25det and am fitting tomei 270 degree 10.25 pro cams.

Would just like to know if the standard rb26 solid lifters are ample enough to cope with these cams as i can access a set for pennies compared to lifters from tomei. I know about the gtr's running different length valves compared to the gtst but i can make the difference with made shims (hardened) so that shouldnt be a problem.

thanks for any advice all

 

[stevros]

Has anyone here run their gtr on 270's using the stock solid lifters? I jus want to know if the lifters surface was upto it that contacts the cam lobe?

 

[FRRACER]

With procams Tomei do say you need to buy their lifters this is because the base circle of the mid-high lift cams is 30mm compared to 32mm for anything less.

But I am planning on running a staggered setup of mid and low so not sure what to do there.

 

[Clark Motorsport]

They will run a bigger base circle chances are cam lobe will not turn in the head fouling on the head.

Which part # cams are you using?

GTR step 2 cams require 1mm up buckets

Tomei gear isn't cheap but it is the best

 

[stevros]

But if this is the sole reason it is something that could be catered for by custom shims surely? My main concern is whether the stock gtr lifter is manly enough to cope with the cams aggressiveness?

 

[stevros]

Ill post the part numbers tomo. Jus leaving work lol!

 

[stevros]

I thought 10.25's were safe of fouling the head. Again tho I could get that machined out here but again would this cause a reason to change from one solid lifter to another?

 

[Clark Motorsport]

Actually they will just clear the head on the lobes that isn't the problem.

The problem is the cams I think you have are designed to go with the Tomei RB25 solid lifters and shims which are totally different from RB26 set-up. The shims are concave and sit against the Tomei lifters. The type B springs from Tomei have Titanium retainers just on the exhaust side from memory with collets. RB25 valves are a different in size 7 and 8mm as opposed to 8mm in the GTR.

So in short if you are wanting to make the Tomei step 2 270x10.25mm cams work in your RB25 head you will need the Tomei parts to suit. Other options are using the Neo head which already has solid lifters. Or with a lot of machining (head work) you can make GTR cams and lifters work in the RB25 head.

Dickie

 

[stevros]

Ok thanks for the info, I was hoping I could machine shims to suit the clearance difference and valve spring retainers. I'll bite the bullet and buy the tomei rb25 solid set then and save again for the springs!! Thanks again

 

[stevros]

Jus a thought, the shim you say is concave on one side is that the side that the lifter suts against and does this mean the lifter is also curved and not flat, almost like a pivot? Again using a lathe could the shim not be made to sit in the top of the valve retainer be it 7 or 8 mm?

 

[Clark Motorsport]

The concave side of the shim is the side that meets the lifter. The shims are a Tomei design.... a one off.

Will PM you the details in the morning of what you need.

Dickie

 

[stevros]

Ok thanks as I still cant see why I cant make shims to suit the gtr lifters!?!
Sorry if im questioning a lot but I want to understand why it wont work!
Thanks

 

[scoooby slayer]

my rb26 head runs 260 degree 10.3mm lift cams and the head is clearanced for the lobes to clear.

 

[stevros]

Is that on stock lifters?

 

[scoooby slayer]

Is that on stock lifters?

I don't know, I just left the lifters and shims as they were and checked clearances when I reassembled after doing headgasket and they were all in spec.

I didn't measure the lifters but I did measure the cams to check what was in it while it was apart and I noticed the head was clearanced quite a bit for the lobes to clear.

 

[stevros]

Ok thanks for the info bud

 

[scoooby slayer]

Ok thanks for the info bud

no probs I wish I could be more help.

 

[stevros]

another question!
how is the cam made for tomei lifters? is it to do with the surface that contacts the lobe? it was mentioned use a neo head as it has solid lifters, why would that be any different to putting gtr lifters in my head? the standard gtr lifters are flat bottomed so surely making shims is easier with flat surfaces? 7 or 8mm that can be catered for with a lathe as with any kind of shape to sit in the spring retainers. like i say i cant see a hard reason not to use them with custom shims unless the gtr's contact surface isnt up to the beating from the cam??

 

[Corsa1]

Only just seen this yes you can use the RB26 retainers and cam followers and the make the shims up to your spec,if you need any help just PM me
Hope this helps.

 

[Clark Motorsport]

Is it as easy as that Andy with the Tomei cams? Just drop in RB26 followers Springs and shims