Rb26 Cam Choice

[Sydneykid]

This "machining" of the cylinder head to clear high lift cams is grossly overrated. I "machined" an RB26 cylinder head to clear 10.3 mm lift cams yesterday in less than 20 minutes with the die grinder. And I didn't take the cylinder head off to do it either. Just had the trusty vacuum cleaner in action and some gladwrap.

Think about the numbers involved. If 9.8 mm clears easily, then the max you have to remove is 0.5 mm. That is hardly MACHINING :lol: :lol:

Cheers

[IMACUL8]

When you say "machine" or modify head to fit - do you have a picture of head and which parts need to be cleaned up.

Sorry for noob question - just trying to understand it all .

Daniel

[pnblight]

another thing to note is the bolt in tomei poncam has a base circle of 32mm and a lift of 9.15mm

But the tomei procam has a base circle of 30mm and the 10.25mm lift cam would only have a total 0.10mm higher total lumb hieght. Meaning i believe if you were willing to reshime the head the tomei 10.25mm should go in without machining.

pete

[pnblight]

  IMACUL8 said:

When you say "machine" or modify head to fit - do you have a picture of head and which parts need to be cleaned up.

Sorry for noob question - just trying to understand it all .

Daniel

<{POST_SNAPBACK}>

i dont have a pic but if you look at where the bucket runs under the cam you will see the there is a cut away through the bucket tunnel to clear the lumb of the cam this cat away is what has to be relieved to clear the larger lumbs.

pete

[IMACUL8]

Thanks Pete

What Cams have you put in Jemery's car. I love the way that sounds and seems to haul very nicely.

Dan

[saliya]

  Sydneykid said:

This "machining" of the cylinder head to clear high lift cams is grossly overrated. I "machined" an RB26 cylinder head to clear 10.3 mm lift cams yesterday in less than 20 minutes with the die grinder.  And I didn't take the cylinder head off to do it either.  Just had the trusty vacuum cleaner in action and some gladwrap.

Think about the numbers involved.  If 9.8 mm clears easily, then the max you have to remove is 0.5 mm.  That is hardly MACHINING    :lol:    :lol: 

Cheers

<{POST_SNAPBACK}>

... weren't you frightened of swarf melting its way through the gladwrap ? And did you take any pics

(I am currently investigating 'how hard' this is to either do myself or get someone else to do...)

Regards,

Saliya

[Sydneykid]

  saliya said:

... weren't you frightened of swarf melting its way through the gladwrap ? And did you take any pics

(I am currently investigating 'how hard' this is to either do myself or get someone else to do...)

Regards,

Saliya

<{POST_SNAPBACK}>

Nope, the aluminium is relatively soft, doesn't get very hot and it was only 0.3 mm that I was removing. It's not like there is tonnes of half molten swarf flying all over the place. The glad wrap is really just there to concentrate the vacuum pick up from the cleaner.

That engine is running, tuned and gone today. I can take pictures of my own RB26 cylinder head if you like, it has been machined for Jun 272/280 with 10.5 mm lift. If you take a camcover off it is easy to see what has to be done to make room for an extra 0.5 mm larger lobe on the camshaft. There is no magic, the most common reaction when I show people this HUGE MACHINING job, is " is that all it is?"

cheers

PS; I am sure one of the guys posted up some pictures a while ago, maybe try a search. If I remember rightly his job was very nice, but a big overkill using a mill and removing 1 or 2 mm, just to be sure.

[pnblight]

  IMACUL8 said:

Thanks Pete

What Cams have you put in Jemery's car.  I love the way that sounds and seems to haul very nicely.

Dan

<{POST_SNAPBACK}>

jezzas is running tomei poncams, Yes it's a VERY nice ride with great responce and linear power delivery, which should stand him in good sted for track days etc. I have know fitted 5 sets of these Tomie Poncams all with out a problem and all with good results (ie my tip is to get adjustable cam wheels (tomei) with the cams) as tuning the cams is where you really unlock the potiental of the rb26 some more than others.

peter

[Fitzpatrick Speed Works]

troy did his on a mill he has photos of the process, i'm with sk i do them with the die grinder it takes no BS half hour including cleaning time!

[JH32]

are they the 260deg in/ex pete?

[pnblight]

  JiMiH said:

are they the 260deg in/ex pete?

<{POST_SNAPBACK}>

yes i dont think it worth bothering with stage 1 the stage 2 are the only ones i recomend

pete

ps the last 3 gtrs with these cams have averaged 500rwhp with small twin turbo combos

[Topaz]

The tomei ones I was looking at yesterday were 9.15/260deg...how does that rate compared to other lifts and degs?

these were $1400 for pair as well, is that an average figure?

I know nothing about cams and timings etc, but want to know before I get into modifying next year...

[pnblight]

  Topaz said:

The tomei ones I was looking at yesterday were 9.15/260deg...how does that rate compared to other lifts and degs?

these were $1400 for  pair as well, is that an average figure?

I know nothing about cams and timings etc, but want to know before I get into modifying next year...

<{POST_SNAPBACK}>

there the go but maybe try greenline.jp or nengun.com might save your self some money

[MattSR]

Extra lifft is always good, it gives you and increase of torque right across the rev range when tuned correctly

[Topaz]

  pnblight said:

there the go but maybe try greenline.jp or nengun.com might save your self some money

<{POST_SNAPBACK}>

ok, that price was from Unique Autosport or something.... (www.nismo.com.au)

EDIT: according to Greenline the Tomei camsharft from 252/9.5 (LOW) all the way up to 290/11.50 (SUPER HIGH) ar exactly the same price

Approx. $350-$360 each

which fits straight into an R32 GTR? or do they all fit?

[Mik]

  Sydneykid said:

This "machining" of the cylinder head to clear high lift cams is grossly overrated. I "machined" an RB26 cylinder head to clear 10.3 mm lift cams yesterday in less than 20 minutes with the die grinder.  And I didn't take the cylinder head off to do it either.  Just had the trusty vacuum cleaner in action and some gladwrap.

Think about the numbers involved.  If 9.8 mm clears easily, then the max you have to remove is 0.5 mm.  That is hardly MACHINING    :lol:    :lol: 

Cheers

<{POST_SNAPBACK}>

SK...when you say 9.8mm clears, do you mean cams with a smaller base circle? I know on my head, there was next to no clearance (about 0.5mm) with 9.15mm PONCAMS.

[blk180]

I think/all most jun cams have a 31 base circle

[druzilla32]

  Topaz said:

The tomei ones I was looking at yesterday were 9.15/260deg...how does that rate compared to other lifts and degs?

these were $1400 for  pair as well, is that an average figure?

I know nothing about cams and timings etc, but want to know before I get into modifying next year...

<{POST_SNAPBACK}>

if your interested in a contact i got mine for 1100... poncams 9.15/260deg.

also a quick question..

how SHOULD an r32 gtr run with tomie poncams using a standard ecu?

[R32-GTS]

Only my opinion but the HKS camshafts look alot higher quality and nicer finish compared (yes i have seen both) to the tomei cams i saw and the 3 cars with HKS cams that i know of average over 600rwhp so yeh my preference is HKS cams but only my opinion. Mine havn't even been dialled in yet at 608rwhp.

[Topaz]

  druzilla32 said:

if your interested in a contact i got mine for 1100... poncams 9.15/260deg.

<{POST_SNAPBACK}>

nah, I am planning on computer, cam gears, belt and boost increase first. Cams and other internals later on. thanks anyway

Also, I found the Tomei Cams (IN260deg / EX252deg / L9.15mm) at Nengun for $887 delivered for the RB26DETT:

http://www.nengun.com/catalogue/product/38