Will an electric water pump and a performance harmonic damper really help anything with performance?

Not measurably. The power to drive the electric water pump makes up for most the parasitic gains. A harmonic balancer has no effect on horsepower - same as a lightened flywheel.

Typically an aftermarket harmonic balance is added for safety, not for performance. They are required by some racing organizations at higher levels of performance. The electric waterpump is typically used on drag racing cars that are not driven on the street, they are not relaible enough for day to day use.

Electric water pumps do free up some power. I don't know of anyone who has actually measured the RWHP difference before and after the swap though.

CSA make a dedicated L Series water pump that looks like its a quality part. I have one but not used it yet as it's for my next performance engine build up for my 240C. The idea of them failing applies to any engine component, so don't base your choices solely on this.

The advantage may be in that one is able to run the pump at an optimum speed to avoid cavitation and significantly reduce the chances of local boil and steam pocket formation in and around thee cylinder head. Properly setup then, one can run higher comp. ratios without fear of detonation etc. So, it may not be a major power producer (or liberator) by itself but may be instrumental in helping other systems work closer to optimum.

Same goes for the balancer. It will help the crank from self destructing due to harmonics so I guess its a good part to have unless you've got a lot of money lying around to build a new engine. Then, it wouldn't/shouldn't be a problem anyways, I guess.

Cheers.

IIRC our cranks are internally balanced, ie unlike domestic v8s that require the use of an external balancer.

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IIRC our cranks are internally balanced, ie unlike domestic v8s that require the use of an external balancer.

Well... that's true at some order of harmonics, but a reciprocating assembly can never be perfectly balanced internally. You need masses as each end to help dampen non-primary order harmonics.

  John Coffey said:

Well... that's true at some order of harmonics, but a reciprocating assembly can never be perfectly balanced internally. You need masses as each end to help dampen non-primary order harmonics.

Are you referring to the catastrophic 7500+ harmonics or other harmonics in general? Just trying to gain some knowledge.

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Are you referring to the catastrophic 7500+ harmonics or other harmonics in general?

I've never heard of "catastrophic harmonics" at 7,500 rpm! I need to tell my ITS racing buddies about that and have them stop revving their L24s to that rpm. L6 engines on mildly modified cranks can spin to 8,000 rpm plus with having a catastrophic failure - if they are running a harmonic balancer.

There are harmonics (2nd, 3rd, 4th, 5th order, etc.) throughout the rpm range of the engine that need to be dampened. BMW 6 cylinder engines are famous for breaking cranks when the bling bling racer boys install cheap aluminum crank pulley/balancers. Thankfully this trend hasn't made it into the Nissan L6 world.

Things like electric water pumps should not be relied on for HP increases. Your talking about minute HP that people chasing thousands of a second may do. I would wager this is not you. Never underestimate the quality of stock Datsun parts. Shiny parts in a catalog look good on paper, but seldom live up to the hype in actual returns. Use stock when you can, focus your efforts on parts that will make it run strongly and reliably. Build your engine for the driving you do every day. Trying to live day to day with a high strung motor that is only happy at 6k+ every day is not money well spent. Sacrifice some of that peak HP for strong daily reliability.

This is of course unless your building a drag car. Then ignore my post entirely.

  John Coffey said:

I've never heard of "catastrophic harmonics" at 7,500 rpm! I need to tell my ITS racing buddies about that and have them stop revving their L24s to that rpm. L6 engines on mildly modified cranks can spin to 8,000 rpm plus with having a catastrophic failure - if they are running a harmonic balancer.

There are harmonics (2nd, 3rd, 4th, 5th order, etc.) throughout the rpm range of the engine that need to be dampened. BMW 6 cylinder engines are famous for breaking cranks when the bling bling racer boys install cheap aluminum crank pulley/balancers. Thankfully this trend hasn't made it into the Nissan L6 world.

Thanks for the reply John. I had heard that there was some inherent weakness in the crank when the L-series was at 7500 rpm for a length of time. Unfortunately I don't recall where exactly I heard that from; perhaps over at hybridz...

You need to keep the water pump and invest in an electric fan. Without a fan clutch you will feal the HP gain in the seat. Not much but enough to enjoy. 5 to 10 HP at the most.

  John Coffey said:

There are harmonics (2nd, 3rd, 4th, 5th order, etc.) throughout the rpm range of the engine that need to be dampened. BMW 6 cylinder engines are famous for breaking cranks when the bling bling racer boys install cheap aluminum crank pulley/balancers. Thankfully this trend hasn't made it into the Nissan L6 world.

Chrysler 2.0/2.4 4-bangers have similar issues w/ the non-damping crank pulleys, except they break the oil pump. It can happen even when not running high revs all the time (ie street use).