Valve Clearances For Tomei Cams In A Neo

[camoo]

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

[kitto]

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.

[JustinP]

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 So thats what I set mine to. I also installed stronger valve springs.

[kitto]

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?

[JustinP]

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.

[kitto]

Yeah, would have been done by valve seating / shaving the valve stems

[The Dan]

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

[The Dan]

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

[wolverine]

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.

[wolverine]

Link to Tomei valve clearances part way down the page.

http://www.tomei-p.co.jp/_2003web-catalogue/efr-set_camshaft_rset.html

[kitto]

Precision Shims Australia have them

This useful to know when i drop in some Tomei cams down the track.

I think the exhaust runs such a large clearance because of the alloy buckets.

[The Dan]

This useful to know when i drop in some Tomei cams down the track.

I think the exhaust runs such a large clearance because of the alloy buckets.

What alloy buckets?

[kitto]

Exhaust lifters in a NEO are a non ferrous metal of some description. Appeared to be aluminium. But id guess they are an alloy.

[JustinP]

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

[black bnr32]

I`m running .014" intake and .012 exhaust

[Cyifly]

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 November 27, 2012 by Cyifly

[camoo]

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

[Cyifly]

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 November 28, 2012 by Cyifly

[camoo]

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.

[kitto]

Hmmm, noise isn't what you want.

Valve train should sound like a ' smooth sewing machine' at idle / low revs.