Tomei Poncam Type B USA and Japan version differences

[nouveau_poor]

Hey all,

Was looking to get some cams for my R32 GTR and noticed that the popular Tomei Poncam Type B's seem to have two different versions between the USA and Japan.

From Tomei USA's site, for part TA301A-NS05C, the duration is 262 with 9.15mm lift. On the Japanese sites like Nengun or RHDJapan the duration is 260 with 9.15mm lift. Is there different versions between USA and JP spec? I don't think it's a typo since the different US suppliers I check have the same information. Both parts are part number 143005. RHDJapan has them for comparable prices to US suppliers, but Nengun lists them for almost 40,000 yen (400$) more, adding more to my confusion. I wouldn't think that a difference of 2 in duration would make all that much difference but am more concerned about possible differences in materials or manufacturing process. Can anyone shed any light on this? Thank you

 

 

 

[GTSBoy]

Note sure that it matters when better cams are available. Lift is king.

https://www.kelfordcams.com/global/camshafts/nissan/rb26dett/182-b-camshaft-set.html

https://www.kelfordcams.com/global/camshafts/nissan/rb26dett/182-c-camshaft-set.html

[joshuaho96]

On 3/6/2022 at 8:57 AM, nouveau_poor said:

Hey all,

Was looking to get some cams for my R32 GTR and noticed that the popular Tomei Poncam Type B's seem to have two different versions between the USA and Japan.

From Tomei USA's site, for part TA301A-NS05C, the duration is 262 with 9.15mm lift. On the Japanese sites like Nengun or RHDJapan the duration is 260 with 9.15mm lift. Is there different versions between USA and JP spec? I don't think it's a typo since the different US suppliers I check have the same information. Both parts are part number 143005. RHDJapan has them for comparable prices to US suppliers, but Nengun lists them for almost 40,000 yen (400$) more, adding more to my confusion. I wouldn't think that a difference of 2 in duration would make all that much difference but am more concerned about possible differences in materials or manufacturing process. Can anyone shed any light on this? Thank you

There's a lot of drama around Tomei USA, you can look at this post to get an idea: https://www.ft86club.com/forums/showthread.php?t=134044

Personally I don't buy Tomei USA parts because in the groups I'm in I've seen people get Tomei USA cams that don't even fit in the engine because they were machined so far off from correct. On top of this I have seen people claim that they have gotten head gaskets that were faulty from the very first turn of the key. Obviously there's some doubt as to whether the machine shop/engine builder adhered to all the necessary requirements to ensure that the deck/head were properly prepped and all that fun stuff but they claimed it was. That combined with a few other people mentioning issues they've heard was enough that I will never buy a Tomei USA part. If you think spending a little more on shipping to get a camshaft is expensive I would probably think hard about the cost of potentially having to do a camshaft replacement twice or having to spend weeks RMAing your part to Tomei USA and getting a replacement that may or may not be any better.

Also, consider what your goal is with these cams. If you want better response more cam duration is probably counterproductive which is why Tomei JP makes the type R Poncam. The 260 cams cause mild idle lumpiness which you may find desirable but is caused by poor combustion stability at idle.

[nouveau_poor]

Thanks for the feedback both. Reason I ask is that they seem to be a popular modest cam to pair with Garrett -5 turbos, where I'm shooting for the 450-500hp range. An opportunity came up where I could get them BNIB off somebody going a different direction with their build for about 1/3 the normal retail price. Really has me eying them. I'll read through the TomeiUSA forum post that was provided 

[Dose Pipe Sutututu]

Tomei USA is not Tomei.

Tomei Japan is Tomei.

[nouveau_poor]

Finished reading around a bit. So with the official announcement was in 2019, anyone know when Tomei JP stopped supplying cams to Tomei USA from Japan or if Tomei USA has always made their own cams? Definitely going to dig further

[Dose Pipe Sutututu]

If I were you, I would just get Kelford cams.

[BK]

Take this advice above

[nouveau_poor]

Yeah, more searching around was enough to spook me away from them even if the full details about their relationship isn't completely clear. The discount is huge but maybe the above is the reason why, now that I think about it. Not keen on risking an ill fitting cam, or worse a snapped one. 

Will check out the Kelfords. Any strong opinions on similar spec HKS cams? Seem to be close in pricepoint and I've been very pleased with the other parts they produce. 

[joshuaho96]

On 3/6/2022 at 5:38 PM, nouveau_poor said:

Finished reading around a bit. So with the official announcement was in 2019, anyone know when Tomei JP stopped supplying cams to Tomei USA from Japan or if Tomei USA has always made their own cams? Definitely going to dig further

Tomei USA made the change a while back to their own spec cams to cut cost, I don't recall when exactly it happened though. WD's experience with snapped Tomei cams is possibly a crappy casting but I wouldn't be surprised if the previous owner just completely failed to adhere to proper procedure setting timing belt tension or installing the cams. Tomei JP's cams are made in-house although not all of their components are built in-house. The stories and photos I saw were not posted to Youtube or anything like that, it was a local private Facebook group.

HKS' cams are fairly conservative with valve lift so I don't know if it makes any sense to go with them, you can go up to ~9.15mm before you have to clearance the head for a high lift camshaft. Something I've wondered for a while now is just how much of the improvement with these drop-in cams can actually be attributed to the lift/duration changes when they seem to be making non-trivial changes to cam timing as well.

[robbo_rb180]

Kelford would be the best option. More lift and not over hyped products from 2002.
Email Kelford with what you want to achieve and get what they recommend, probably even do valve springs at same time.

[nouveau_poor]

On 3/6/2022 at 10:48 PM, joshuaho96 said:

Something I've wondered for a while now is just how much of the improvement with these drop-in cams can actually be attributed to the lift/duration changes when they seem to be making non-trivial changes to cam timing as well.

I think I've read in another thread that one of the best "simple" changes to the engine one can do is to tune some adjustable cam gears and that even on factory camshafts a gear tune can give additional power.

Maybe there is a compare and contrast thread out there for the same engine setup. One with factory gears/cams, one with adjusted gears/factory cams, one with one with adjusted gears/aftermarket drop in cams. 

[joshuaho96]

On 3/11/2022 at 8:15 PM, nouveau_poor said:

I think I've read in another thread that one of the best "simple" changes to the engine one can do is to tune some adjustable cam gears and that even on factory camshafts a gear tune can give additional power.

Maybe there is a compare and contrast thread out there for the same engine setup. One with factory gears/cams, one with adjusted gears/factory cams, one with one with adjusted gears/aftermarket drop in cams. 

The centerlines on most aftermarket cams are different from stock, so keeping the same settings on aftermarket cams after adjusting for stock wouldn't make sense necessarily. You'd want to try stock cams + timing, then aftermarket drop-in cams at their default timing, then use the cam gears to adjust the timing back to be the same as stock cams.

Also, don't forget to torque those cam gears to spec and use blue loctite because otherwise this can happen and you'll bend a bunch of valves and maybe destroy your head too: https://www.youtube.com/watch?v=kI7GFPYDtOo&t=625s

Edited March 12, 2022 by joshuaho96

[nouveau_poor]

On 3/12/2022 at 2:02 AM, joshuaho96 said:

Also, don't forget to torque those cam gears to spec and use blue loctite because otherwise this can happen and you'll bend a bunch of valves and maybe destroy your head too: https://www.youtube.com/watch?v=kI7GFPYDtOo&t=625s

Dang, wonder how that works out with the tuner. Do they fund a new engine or a different way to make it square?

[joshuaho96]

On 3/12/2022 at 12:16 PM, nouveau_poor said:

Dang, wonder how that works out with the tuner. Do they fund a new engine or a different way to make it square?

Knowing who built the engine he will probably be taken care of but for normal people it's pretty fair to say if this happens you are 100% SOL unless the same shop that builds the engine is also doing the tune for it.