hi there. New to this site but am in need of info. has anyone suffered from or heard of the following problem. I have a 3.1 motor running a drysump system. Distributor is still driven from the old gear(steel set up) on the nose of the crank and dummy oil pump to support lower end of drive. I have run the engine for 3 seasons with no trouble and then at the last meeting of last year the dry sump pump belt snaps at 7500rpm. On ripping the motor apart it would appear that the gear that drives the distributor has cracked and a chunk has broken off. This has found it's way back to the dry sump pump and locked it solid breaking the belt. As yet I can see no reason for the drive gear to have cracked. any ideas on what may have caused this or if you know that it has happened in the past would be appreciated as I really would like to have a cause for this before i rebuild the motor many thanks in anticipation. ben

 

Ben240Z,
I would say that its a metalurgical (sp) problem. Any crack or flaw in the piece would eventually fail at that RPM. Was
part magnefluxed before installation ?

I have some buddies who were running the stock dizzy drive gear assembly in order to keep the oil pump and they eventually had failures at RPM with their set up. They were running a crankfire ignition with a plug at the distributor location.

One thing the guys did learn with their other race car , a Twin Turbo Rotary was that they needed a filter to keep exploded
bits from their turbo's . They lost turbos twice when they had internal failures . The pieces were sucked into the turbo oil lines and then the turbos. Pretty costly loss for them . Needless to say the RX7 is now running a NA Nissan VG30E now.

You might give Sunbelt Engines a call and see what they say. Malvern Racing use to have a message board where you could post race engine questions to one of their techs.

Mike

 

thanks for that mike I have spoken to david weber at malvern and the conclusion seems to be that I should be running the bronze gear setup. I am also rectifying my mistake on the dry sump pan of not putting any filtration on the scavenge outlets.We learn by our mistakes however costly boo hoo once again thanks for the reply.

 

I've read about the bronze gears too. I planned on running a steel gear and this is of a concern for me. Any source for the bronze units?

Phil

 

david weber of malvern racing has them on the shelf he says that it is the only setup to use as the steel gears let go often. i have been lucky with the little amount of damage done. every thing that i have bought from david has worked which is why i go to the trouble and expense of shipping it back over to the UK. He has certainly given me good advise and guidence in the past. ben

 

The bronze gear is the only way to go. I have lost one engine years ago and learned the same hard lesson NISMO has it as well part# 15043-73400 Not on the web site you have to call them for it.
Prowrench

 

Thanks for the part #, just ordered mine online through Courtesy Nissan's site. It was in their database.

Phil

 

No sweat, I thought that it would be a high wear item,but I have had one in my 3.2L for AC and the street and rev the crap out of it and it has shown no wear and i have been in that engine a couple of times over the past years. I have used the ones over again in the race cars and they never seem to wear out. Its much better tham when the gear comes apart and you see that OP dip a couple of times and then it gets real loud. and its always at revs so you cant spool it down or shut it off. The accusump helps but the damage is always done...
Prowrench

 

On Courtesy's web site, they say a new spindle pin is required too. Can the old one be reused?

 

I have used the old one but my gears may have been made by someone else back then. You may want to get it if the keyway groove is different ,It counldt be that expensive. not against the cost of a few rods and a crank ) But the old one I used was from the original core motor. That old Japanese stuff just dont seem to wear out.
Prowrench

 

new spindle is recomended and are about $82 much cheaper than an engine rebuild

 

hi guys have any of you got a phone number for nismo as they seem reluctant to answer email enquiries regarding a bronze gear cheers ben

 

You can contact Steve Christiansen at NISMO @ 310-771-5042
prowrench

 

cheers for that mate hopefully i will get more luck on the phone. ben

 

Steve is no longer with Nismo . Last thing I heard is he was working at Mossy Nissan.

Mike

 

Opps sorry I spoke with him last at the Fontana Grand am race in June 03. I was unaware he was gone but that # is still good.
Prowrench