Jump to content
SAU Community

Recommended Posts

Im about to install some tomei type b cams into my r34.

So ive done heaps of searches and it has returned multiple answers...

Does anyone know for certain the valve clearances to follow?

Ive got tomei's specs, nissan workshop specs, under my bonnet the sticker has different specs.

Just looking for some reassurance with which ones to follow, and the searching is doing my head in.

Cheers

What are the TOMEI specs for those cams out of curiosity?

I've heard they are quite large.

People have thrown shims with those cams and i'll bet its because of incorrect shim clearance.

Nissan workshop manual states it is 0.31 +/- 0.04mm on the inlet and 0.5mm +/- 0.04mm on the exhaust.

If I remember correctly (I recently installed the same cams), Tomei says the correct clearance is 0.4mm (intake and exhaust). Seemed quite large, but who was I to argue with the manufacturer :P So thats what I set mine to. I also installed stronger valve springs.

Yeah i put stronger valve springs in mine as well. But i'm only using stock cams for the time being.

Did you set your shim clearance with new shims, or did you rebuild the head and grind the valves down?

Yeah i put stronger valve springs in mine as well. But i'm only using stock cams for the time being.

Did you set your shim clearance with new shims, or did you rebuild the head and grind the valves down?

I'm not actually sure, I had the whole head rebuilt / reconditioned by someone and they set the clearances.

Yeah i put stronger valve springs in mine as well. But i'm only using stock cams for the time being.

Did you set your shim clearance with new shims, or did you rebuild the head and grind the valves down?

Valve regrind, then get your machinist to trim the valves to get the right clearance. If you get stuck and need some, Precision Shims Australia have them

From memory we set them up at 0.016" intake and 0.014" exhaust.

That's about 0.4mm intake and 0.35mm exhaust. If you set them anywhere near 0.018"-0.020" it will be noisy as hell

Mine were re-shimmed to Tomei spec 0.45mm in/ex and there is a bit of noise coming from them. Maybe noisy as hell is a matter of opinion but I would run tighter clearances in future.

Mine were re-shimmed to Tomei spec 0.45mm in/ex and there is a bit of noise coming from them. Maybe noisy as hell is a matter of opinion but I would run tighter clearances in future.

Ahh yes it was 0.45mm... Which is what I set mine too. Hope mine are not too noisy when I get it going :(

I have stage 2 Tomei poncams I'll dig up the receipts and find out what mine are can't remember lol but my head and everything was rebuilt when cams were put in. Oh I'm tuning r34 gtt neo you will love how it sounds when you got em in I know that much

Edited by Cyifly

hahaha once again I have been given several different answers.

Thank u all for the advice though.

Any more experiences?

The size tolerance you used and if it was noisy or not?

Thanks again

Do you mean noisy exhaust wise? Or as in engine cause mine is noisy exhaust wise.

Engine does make a lil bit of noise can really hear when the cams are ticking over. Hope tht answers your noise question

My poncams as per receipt:

260 degrees 9.15mm intake

260 degrees 9.15mm exhaust

Off engineering receipt:

Was machined 20 thou over by memory

List:

Modify pistons to neo spec

Repair can tunnels

Supply retainers and locks

Machine crank and fit sleeve

Supply and fit valve guides

Hot tank engine

Port head to race

Supply valve springs

Fit oversize inserts

Supply inlet and exhaust valves

Bore and hone block

Modify oiling

Supply rb25 crank shaft

Drill and tap oil gallery's

Manufacture seats

Deck block

Manufacture vernier gear

Assemble Aline pistons

Engine balance race bearings

Arp head studs

Seals

N1 oil pump

Welsh plugs

Not sure if that will help at all man but yea.

Was all done at Jhh engineering in Woodbridge Queensland.

Perhaps give em a call cause rb25 rebuilds are what they specialize in race spec.

0732086274

If anyone will have The answers they will just can't remember that far back.

Edited by Cyifly
  • 2 weeks later...

Hey all just an up date.

I checked the clearances and all good, used Nissan spec and they were all within.

The valves are making a decent tick though. Not horribly loud, just enough to be annoying.

Made just over 300 with no loss in response.

So prettyhappy

Thanks all for your responses.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I'm going to slap an old nismo logo sticker on my spare one and sell it to the land of the free for a thousand bucks
    • lol, probably should have read further!
    • Well - they have arrived.  And they are easy on the eye to put it mildly... These only have three bolts - but for a start there is a key that fits with vacuum like precision..  And as you can see by my ruler, the interface is large..   I listened to a podcast on HP Academy about Dan (KiwiCNC) and I'm more than comfortable he knows what he is doing. R35 Bearing assembly should arrive later today so can mock that up for a look. Can't wait to get these on and get some brake pressure logging too. IMG_3860.MP4
    • I would be very confident that they are the same parts (the 2 different SKUs). It seems very clear that you can drop the cam in the 2-way opening, or in the other opening. If you arrange it in the other opening in the same way that you see any other 1-way diff, ie, with the flat of the cam up against the 1° side of the opening, then it would work as a 1-way. It can only spread the ramps when driving forwards - cannot spread the ramps on overrun. It would then appear obvious that if you put the cam into the opening "backwards", that you would get the angled flats of the cam working onto the "points" of the 1° side of the opening, which would give you ramp spread in both loading directions. I do wonder if the forward direction of the 1.5-way config is equivalent to the forward direction of the 2-way, seeing as the cams are flipped and the angled surfaces on those would need to be the same on each side - AND - clearly when installed in either the 2-way or 1-1ay configuration they are not intended to work exactly the same (the ramp angles on the 2-way are 10° different between forward and backward, and the ramp doesn't exist in the 1-way config). 'twere me, I think I would rather actually have a set of rings that offered the 2-way with two different sets of ramp angles, say the 55/45 of the existing design and maybe a 45/37.5 combo for a less aggressive effect), AND another set of rings with a dedicated 1.5-way opening and a dedicated 1-way opening. The 1.5-way opening would actually have the steeper angle on the overdrive side that causes it to be less pushy than the forward drive angle, like you see in many other diffs. But really - if this Nismo thing is thought out properly and all those surfaces work on each other the way that they need to, who am I to argue?
    • I would be very confident that they are the same parts (the 2 different SKUs). It seems very clear that you can drop the cam in the 2-way opening, or in the other opening. If you arrange it in the other opening in the same way that you see any other 1-way diff, ie, with the flat of the cam up against the 1° side of the opening, then it would work as a 1-way. It can only spread the ramps when driving forwards - cannot spread the ramps on overrun. It would then appear obvious that if you put the cam into the opening "backwards", that you would get the angled flats of the cam working onto the "points" of the 1° side of the opening, which would give you ramp spread in both loading directions. I do wonder if the forward direction of the 1.5-way config is equivalent to the forward direction of the 2-way, seeing as the cams are flipped and the angled surfaces on those would need to be the same on each side - AND - clearly when installed in either the 2-way or 1-1ay configuration they are not intended to work exactly the same (the ramp angles on the 2-way are 10° different between forward and backward, and the ramp doesn't exist in the 1-way config). 'twere me, I think I would rather actually have a set of rings that offered the 2-way with two different sets of ramp angles, say the 55/45 of the existing design and maybe a 45/37.5 combo for a less aggressive effect), AND another set of rings with a dedicated 1.5-way opening and a dedicated 1-way opening. The 1.5-way opening would actually have the steeper angle on the overdrive side that causes it to be less pushy than the forward drive angle, like you see in many other diffs. But really - if this Nismo thing is thought out properly and all those surfaces work on each other the way that they need to, who am I to argue?
×
×
  • Create New...