REIMAX (Collar clearances, pics)

[FRRACER]

Tomei pump is not immune from breaking, the flat drive is the real weakness. Jun pumps fail too as do Greddy.

[FRRACER]

Better option here:

https://www.facebook.com/supertecracing/posts/634121623340933

The slack with Reimax was just shocking, more than the optimal clearance needed for a flat drive setup! I cannot accept that so the Spline drive will be the best option going forward.

[Black BNR32]

Anybody had a Reimax gear set break? I'm still really torn between getting a tomei pump, putting in a head restrictor and calling it a day, or just putting in the reimax gear in my std pump and calling it a day.

I use my GTR for street use mainly, and will be taking it to the track for autox, and time attacks once I have completed the necessary cooling mods & baffling in the oil pan. So I think the reimax would be more than enough for my requirements. Just planning on going uprated turbos, and boost. Probably around 400-450AWHP, nothing crazy, just reliable fun power.

But part of me wants to go full out with the Tomei pump and head restrictor...

Go with the Reimax IMO. i doesn't sound like you'll be putting the pump through much of the real nasty stuff, such as banging off the limiter, extended time in the high harmonics rpms, etc.

[Black BNR32]

This is an interesting thread. Just got off the phone from my engine builder who has Built engines for Nismo when they raced the skyline in GT500 class as well as Nissan touring cars in the UK. According to him there should be clearance between the crank and inner gear to compensate for flexing in the crank at high rpm. A tighter clearance would be good for low end rpm but would shatter the gear at higher rpm. I have a new r34 crank and a reimax gear kit. Will do some measuring later and post the results.

I retract some of my earlier statements in this thread and now agreee with this.

[Armanio]

Anybody had a Reimax gear set break? I'm still really torn between getting a tomei pump, putting in a head restrictor and calling it a day, or just putting in the reimax gear in my std pump and calling it a day.

I use my GTR for street use mainly, and will be taking it to the track for autox, and time attacks once I have completed the necessary cooling mods & baffling in the oil pan. So I think the reimax would be more than enough for my requirements. Just planning on going uprated turbos, and boost. Probably around 400-450AWHP, nothing crazy, just reliable fun power.

But part of me wants to go full out with the Tomei pump and head restrictor...

[FRRACER]

I measured mine today (just the reimax gear) on a brand new crank. Clearance was 0.17 one side and 0.16 the other.

[FRRACER]

This is an interesting thread. Just got off the phone from my engine builder who has Built engines for Nismo when they raced the skyline in GT500 class as well as Nissan touring cars in the UK. According to him there should be clearance between the crank and inner gear to compensate for flexing in the crank at high rpm. A tighter clearance would be good for low end rpm but would shatter the gear at higher rpm. I have a new r34 crank and a reimax gear kit. Will do some measuring later and post the results.

[tinytom]

don't forget it's a 2 pc inner gear. if you want to compare clearance of 1 pc to 2 pc inner gears need to measure total clearance... crank to spline adapter + spline adapter to inner gear (2pc) = crank to gear (1pc). splines allow stuff to flex. too bad that set up doesn't fit into stock housing and too bad it cost 5 times more than upgraded gear...

[Dragon Humper]

I find it funny that anyone who has a motor kack in the first 500km doesn't become incredibly anal about checking the clearances on all the bearings (the UK thread). I see he is just putting her back together with all new parts and no mention of even using some plasti-guage just to double check things are ok, or why he had intermitent oil pressure. The last motor I built I had it together and apart 4 times dry checking absolutely everything (obviously not turning anything, which is why it was 4 times). Everything was right on the money and it is still running to this day (8 years later) putting out 100hp more than stock parts should.

Thread suscribed......


Jon.

[tryingtobebest]

SO, i find a new thread on gtr.UK - http://www.gtr.co.uk/forum/107051-my...project-4.html, in which the guy comparing N1, REIMAX and the best pump that is everybody is comparing - TOMEI one, and the Tomei pump, has the smallest clearances from all of them, im not saying that the TOMEI is UNBRAKABLE but the Tomei is become very popular because of the longivity! They puposly decrease tolerance which i think is the only way to go! TOMEI tolerances are bout 0.002-0.003 each side! - Very tight fit!

Food for thinking #2
Please post some ideas to which company you think is going the right way
Larger tolerances VS Tighter tolerances

[Dragon Humper]

That makes sense, it's a long crank, plus there is the thrust clearance to take into account. I think it's really a very fine ballance of having the clearance a tight as possible without having the drive gear affix itself to the crank during ALL possible heat/flex cycles.

Whenever my motor comes apart I will definately be going this route, best bang for the buck.



Jon.

[drew6]

Thought I would throw this in:

About a month ago I purchased a Reimax gear set and sent Reimax an email asking about the extra crank clearance. I just got an email from RHD Japan who was contacted by Reimax about my enquiry (they don't have any English staff) and they were kind enough to get this message to me from Reimax: "'Crank flexes at high rpm. tight clearance causes the gear to contact oil pump housing. tight clearance is only good for low rpm. bigger clearance allows crank to flex without breaking gear or housing'"

It sounds like they purposely built in the extra tolerance.

Food for thought.

[GTRADDICT]

Sorry I didn’t catch this post earlier.
I talked to the president of the company and showed him your pictures. He stated that will not cause a problem. I spoke with other engineers about this issue. They believe the stock gear when pushed beyond “normal” flexes causing failure. They stated the new gear will not break.
I will ask sometime this week what happens if the crank to gear clearance is super tight. It’s worth testing but it might be difficult to remove during the next rebuild. But anyway I will ask the senior people.

Are you talking about reimax???

[jrhdohc]

Sorry I didn’t catch this post earlier.
I talked to the president of the company and showed him your pictures. He stated that will not cause a problem. I spoke with other engineers about this issue. They believe the stock gear when pushed beyond “normal” flexes causing failure. They stated the new gear will not break.
I will ask sometime this week what happens if the crank to gear clearance is super tight. It’s worth testing but it might be difficult to remove during the next rebuild. But anyway I will ask the senior people.

[Black BNR32]

+1....