mjfawke

I have no cat (sucked in everyone - not required on a pre-'72 car!) On occasion, I have made cars behind me disappear in a cloud of soot when it pops... Seems to be more of a problem on hot days.

Yes - you will notice the difference, it will be a little harder to get going smoothly. More revs, a bit more clutch slipping etc. As for 'lose torque' - what a load of total BS. A flywheel is an energy storage device, for lack of a better term, and if you are putting energy into your flywheel, it is not going to your wheels. Think of it in terms of how much effort you have to put into swinging a bowling ball around your head vs. swinging a ping-pong ball. This is why F1 are now using 4.5" clutches...

I tried to get in contact with John Bennet again. Phone rings out, second number is not valid.

Just because the stock style pressed impellers work "O.K." doesn't mean they can't be improved on. The L series pumps used cast impellers with shaped vanes, and they still cavitate like crazy under high RPM. I would have thought the RB was a sorted design, but most of race motors seem to be running de-aeration tanks... The N1 pump being 'low flow' also indicates a cavitation problem with the stock pump. So - it's good insurance... but a bit expensive. In my case, everything is fine until the rad has to work hard, then all of a sudden it takes a 10 degree jump in water temp. It also pump about a litre of water into the catch tank, even though the water temp only hits around 85c to 90c, so I'm thinking cavitation... and the pump is original, and wasn't run with coolant for a period of time.

I rang Steve Newing @ Speed Technology. The pumps were a custom job, and with a head gasket mod supposedly fixed all of the detonation problems. And yes - the RB block does build pressure inside the head - must have restricted outlets. When they did their previous batch, the replacement impeller cost around $330 on top of the price of the pump. The design is similar to the $800 NISMO pump (not the N1). Steve is going to work on a price and email me back. If we can find EcoTrans, I guess we can get some competition going here

Hmmmmm. The phone just rings out...

Whoo hoo! I found the phone number! And it matches the business mentioned above. Md Mc Aliece & Co P/L 23 Webb Road AIRPORT WEST 3042 (03) 9338-5311 (03) 9335-3421 I found the phone number in a story on their LPG bus engine conversion in "Performance Buildups" from 1999, and found it listed for the business above. Which is strange, because in the article they say that Eco Trans is Johns company. I'll call them on Monday.

Yes, it will lower the compression, but because the pistons are now away from the cyl head at TDC, the engine will be more prone to detonation (reduced squish area) and will get worse economy on part throttle (chamber turbulence). That is why you use low compression pistons or increase the combustion chamber volume.

I've looked everywhere. John Bennet (Bennett?) is the guy, heaps of articles in car mags etc. etc., but obviously likes his privacy. Anyway - Steve from Speed Technology used a JB modified pump in Sinisha Banjac's RB27 240Z, so I might start looking in that direction. My engine temp goes out of control every time the air temp goes over 30. Water temp hits 85-90c, which appears to be O.K., but it would be nice to hold it on the thermostat. Everything else has checked out, so it looks like the pump will have to come off next. The pump has never been changed, and the prev owner of the engine didn't use coolant. Took a fair while to get the rust out

But not necessarily on the RB engine. It seems to lack a water outlet restrictor on the motor, and the pressure cap on the radiator will limit pressure on that path to ~ 15psi. So - I don't think this is an engine design which relies on block pressurisation. Modern designs tend to use high water flow instead of high pressure. Which is bad, because the pump looks like cr*p, and I'm sure it cavitates badly. The only saving point is that the area around the pump is cast iron and won't corrode away like the 'L' series engines did. Does anyone know where to get an EcoTech pump for the RB engine? They are based in Melb, but not on the web. They do cavitation-free impeller replacements...

Lol! Yes - they tend to be a bit picky with his engineering certificates.

They're standard from the factory..

What! Someone stole your swaybars!!?! As for grease, that would be repco, supercheap, etc. etc.

'Probably'. My Nolathane bushes in the front never squeaked (well lubed), the Energy Suspension graphite impregnated ones in the rear always squeak... but not badly. Did you grease your swaybar 'D' bushes (are they poly?)?

Well - you don't lube the rubber bushes, so I guess you must have polyurethane. Was it lubed with moly? Regular greases don't to the trick. Polyurethane is a plastic, so it is affected by temperature to some degree. All of the poly bushes squeak, even the graphite impregnated ones. Some people add a grease nipple so the bushes can be greased in place (not sure how effective this is, as the grease needs to get down to the centre support tube and the ends).

That doesn't really answer the question... Assuming you do have poly bushes in the suspension, then squeaking is normal, and you should disassemble and re-grease the bushes. Use a molybdenum grease or assembly lube - don't get it on your skin, however...

Sounds about right, given what you said. For a rebuild, you should be looking at around $700 - $1000, but it depends on how many bearings are replaced - for that price you will only get the main bearings, not the needle rollers under the mainshaft gears, but they usually don't need replacing. A second hand R33 box is ~ $1800 (fairly rare), you can buy a new one for ~ $2800 (one of the importers has some new boxes from Japan - the ad is in Import Performance, but they only mention their new GTR boxes).

Well.... no actually. 'Stock' suspension bushes (eg. lower control arms) are rubber bonded to an inner and outer sleeve, with the outer press fit in to the suspension member, and the inner clamped by a through bolt. They don't shrink/expand, and they don't move around.

Are you using polyurethane suspension bushes?