Camshafts, Camshafts And More Camshafts

[N1GTR]

Hey guys,

Ive put tomei cams in my current motor, and to my suprise had to buy new buckets as i didnt realize they have a different base circle to stock cams. Turns out im not the only one who's fallen for this trap.

As an example, i thought cams would cost about 1k, but then add the buckets and thats 2k. Now, if HKS (for example) cams are 1400 but dont require buckets then you're about 600 infront overall. Make sense?

So, this thread is to hear peoples experiences with cams - who's had success with what etc but more importantly; Do JUN cams require bucket/shim/whatever changes? I know springs should be changed to match lift - but other than springs, what else needs to be changed?

I need to get cams for the next motor im building, which is underway currently (starting from bottom end first) and would love to just get the right cams this time without spending huge amounts of coin

Thanks everyone

[Adriano]

Ive got 10.2mm 272deg toda cams that apart from the head clearancing and upgraded springs(hks) dropped straight in with a few shims needed here and there.

[den001]

same as above for hks cams, 272 10.2mm dropped in bar the lobe clearances

be weary as the hks cams come in 2 different base circle sizes also

Edited February 18, 2009 by den001

[Swiper the Fox]

Hey guys,

Ive put tomei cams in my current motor, and to my suprise had to buy new buckets as i didnt realize they have a different base circle to stock cams. Turns out im not the only one who's fallen for this trap.

As an example, i thought cams would cost about 1k, but then add the buckets and thats 2k. Now, if HKS (for example) cams are 1400 but dont require buckets then you're about 600 infront overall. Make sense?

So, this thread is to hear peoples experiences with cams - who's had success with what etc but more importantly; Do JUN cams require bucket/shim/whatever changes? I know springs should be changed to match lift - but other than springs, what else needs to be changed?

I need to get cams for the next motor im building, which is underway currently (starting from bottom end first) and would love to just get the right cams this time without spending huge amounts of coin

Thanks everyone

The base circle dictates what size shim you require to get the clearance right...JUN like to tell you to use a really thick shim to make this clearance right...i dont recommend this...the thicker bucket is always the better more reliable way to go, which is how Tomei do it. PM unique1 and ask him what happens when you run a 'tall' shim instead of the thicker bucket and a reasonable size shim...it will cost you a lot more than doing it right once. Please don't take short-cuts mate...id hate to see you bitten again.

Edited February 18, 2009 by DiRTgarage

[N1GTR]

Cheers guys

[Betz]

I have held off on cams due to this same shim/bucket issue, cam upgrades dont seem to be such simple "drop in" jobs as the kits suggest.

[Swiper the Fox]

I have held off on cams due to this same shim/bucket issue, cam upgrades dont seem to be such simple "drop in" jobs as the kits suggest.

32mm base circle cams are a 'drop in' nothing else. Id suggest anyone putting 32mm base circle cams in to do a quick bucket clearance check just to make sure its ok.

Edited February 18, 2009 by DiRTgarage

[Tangles]

rb25: Tomei 256deg cams and 8.8mm Tomei springs are a good fit !

rb26 - dunno sorry, but something like the above would probably only be "mild" on a built rb26. 272's then, perhaps.

what turbos, bottom end combo will the head be utilising, plz ?

[Public Enemy]

yeap i've been bitten by using JUN cams with standard buckets and big shims. Destroyed the entire head when the sim popped out of the bucket. Had to do it all again.

[Swiper the Fox]

yeap i've been bitten by using JUN cams with standard buckets and big shims. Destroyed the entire head when the sim popped out of the bucket. Had to do it all again.

yeah...another one eh...bummer.

if you look on the JUN website it lists the 'tall' shims they advise you to use. In my opinion this is a dangerous practice and has been proven so with many shim 'pops'. Did you use the JUN offset retainers as they have 2 offset types that take up 0.5mm and 1.5mm clearance respectively?. With a 29mm base circle camshaft if you use the 1.5mm offset retainer and the 1mm thicker Tomei bucket you only have to use around a 0.5mm thicker shim than standard. This is the best way to go if using 29mm base circle cams.

Edited February 18, 2009 by DiRTgarage

[N1GTR]

I have held off on cams due to this same shim/bucket issue, cam upgrades dont seem to be such simple "drop in" jobs as the kits suggest.

Exactly

From further investigation it looks like JUN sell a package including buckets etc

rb25: Tomei 256deg cams and 8.8mm Tomei springs are a good fit !

rb26 - dunno sorry, but something like the above would probably only be "mild" on a built rb26. 272's then, perhaps.

what turbos, bottom end combo will the head be utilising, plz ?

HKS GT-RS's

Full built RB30 bottom

[SimonR32]

i ran jun 272 10.5mm with bigger shims and did not have a problem!!!

which tomei cams needed shims, i believe 272 10.2 are straight drop ins and 272 10.8 need shims or buckets yes?!?

[Slide]

Ive got some "big" > and little Tomei and HKS shafts for you "big" fella, you know you want them, "big"ger is better lol

Call me when you are free

[N1GTR]

Oh my, they are big!

[unique1]

i wasnt the person who had issues Dirt it was Public Enemy i think u were thinking of. I run the biggest lift cams Jun make and never had an issue in 2 years+ of over 550rwhp and 8500rpm+, i recently bought a set of Tomei buckets though after hearing of the possible dramas, just to keep my mind at ease.

Edited February 19, 2009 by unique1

[Swiper the Fox]

yeah after he posted i realised i had you two mixed up.

Edited February 19, 2009 by DiRTgarage

[N1GTR]

i wasnt the person who had issues Dirt it was Public Enemy i think u were thinking of. I run the biggest lift cams Jun make and never had an issue in 2 years+ of over 550rwhp and 8500rpm+, i recently bought a set of Tomei buckets though after hearing of the possible dramas, just to keep my mind at ease.

So until then you used standard buckets?

[unique1]

So until then you used standard buckets?

yes standard buckets and bigger shims from precision shims. the shims are pretty damn thick due to the small base circle so it isnt ideal at all, but it works none the less, but im changing them over just to save a disaster arising after hearing about Public Enemy's dramas.

[N1GTR]

Fair enough, cheers

[Public Enemy]

yeah i used the JUN cam package that includes cams, Titanium retainers and type 2 springs. My understanding was that this package would be put together to be compatible with the base circle of the JUN cams. The shims were huge from memory and destroyed the retainers when they came out and then the retainers cracked the standard lifters which messed up the casting of the head. Lotta $$ porting and polishing that head and it went in the bin

Ah well live and learn.

Anyway now using Tomei 272 10.8 cams, Tomei buckets and Tomei type C springs.

So far so good but only a 1000 odd Kms on this step up.