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yep, oil supply issue. this time the cam broke before the bearings spun, which was a nice change. lots of damage to the head tunnel where it was oil starved so it was easy to see the cause.

the oil galleries in the head are tiny and hard to clean out. we drilled out the ends to clean them and put threaded plugs back in afterwards. A bit of a pain but we know it is perfectly clean and easy to re-clean in future. The galleries to the cam journals are absolutely tiny.

  • 2 weeks later...

Looks like I was just unlucky with the cam. But there is not shit through the engine, cam cap is fine, and valves appear to be fine!

this is good news, you'd be laughing if you could just chuck a new cam at it and go again.

  • 2 weeks later...

here is the oil pump.

Remove the 8 screws off the back with an impact driver.

f672ab72.jpg

remove the cover.

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remove the inner gear.

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remove the outer gear

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reverse steps to put back together.

So these gears work ok on a std sized RB20 crank. I am in two minds of whether I should just throw a washer in my current oil pump or grab some gears and shim it up and put higher spring in it whilst it is off the car. But not touching engine so cant do anything about the std RB20 crank.

We are talking band aids here for taking a std wrecker engine to power and boost levels even I am not comfortable with :)

unless you need more oil pressure I wouldn't worry about it. I only did it because I put too small restictor in, and was starving the head....and to use launch control without smashing the pump to peices.

It will go straight onto a std crank, but too much oill pressure, and it will try and it will try and turn the drive off the crank.

Just leave your wrecker motor sealed, and throw 30psi at it. :D

Edited by sav man

what's oil pressure like atm? If the bearing clearences open up too far, no amount of spring pressure on the releaf valve will help.

Once the sump is off shimmig up the spring is easy, just a 24mm socket.

I have not run my data logger in years and lost all the data I did have with an old laptop. Its all getting re-wired over the next few weekends and will see what its doing. I am tempted to drop the sump and throw a ~2mm shim in the oil pump. Going to drop the rev limit to around 6,800-7,000rpm so that will hopefully keep it together

  • 2 months later...
  • 3 weeks later...

Somthing i have been working on to overcome a problem we stumbled across during Targa 2012 is a high output alternator.

The situation: we rock up to the start of howell day 1. its raining and the windscreen fogs up on the start line. at this point we have 95% of the cars stripped back electrics turned on. Wipers, lights fog and head (lights on is a requirement for targa) thermo fan (sitting at start line - doesnt come on during racing) 2 fuel pumps, heater fan, rear screen demist and electronics (abs, dash, ecu, intercom, heated wide band ect) We then for the first time in a race situation turn on the new heated front windscreen. a few minutes into the stage we hit a 1km long strait. at 200+ speeds the wipers struggle to come back down the screen, then they stop half way, we brake for the end of the strait and the abs light comes on and pulling out of the corner the engine starts to miss. ben realises we are fast running out of power and switches everything he can off. the car picks up power and the abs light goes out. we stop for fuel at the end of the stage and the car is dead. no life left in the battery at all. this could have ended our targa then and there but instead a cam decided to brake. WTF.

The Assessment: It was obvious that the new windscreen had caused the issue but its needed when ever its raining so a requirement of wipers and lights is needed. During service we did a quick run over the car and found that we could get rid of the rear screen and turn off the heater fan when ever the front screen was on. also making sure only the fog lights were on when front screen was on.

The Theory: Rough current draw figures are as follows.

Themo fan 10a

Heater fan 10a

lift pump 8a

main pump 18a

fog lights 9a

headlights including park 13a

windscreen wipers 12a

rear demist 15a

electronics 10a

New heated windscreen 40a total.

thats 144 amps roughly if everything is on. the output of a stock RB (20-26) alternator is 80a

we cut what we had to after day one so with the massive load of the windscreen the system neither charged or discharged. there was no margin for error.

the solution: After a bit of time selecting a hand full of possible replacements out of a book they were all thinned out on a output/ modification requirement/ cost basis leaving this 125 amp nissan maxima as the clear winner.

photo3.jpg

i believe a patrol one may have been amongst the final few but its 95-100a output wasnt worth the hassle.

non of the options were going to be a direct bolt on but we were stoked when test fitting we found it bolted up to the original bottom mount and the belts fitted on the stock pulley perfectly. but the stock pulley for the new alternator was designed for a luxury automatic car that never sees revs. to keep to the standard drive a pulley off a rb20 donor alternator had to be machined to fit.

stock

photo5.jpg

new

photo4.jpg

I toyed with ideas about cutting and welding the front housing to suit the original belt adjuster but in the end i opted to make a bolt on bracket that essentially moves the top mounting position to the same place of a factory alt mount. i also made it out of steel as reliability is the key to tarmac rallies.

photo2.jpg

this bracket almost completed a bolt on option with no need to modify the existing engine bracketry. Another huge aspect driving the bolt on theme was we wanted the option to return to a stock alt during the event if need be. So a bit more research went in and i was able to get a plug adapter to change the maxima alt plug to the rb style plug creating a 100% bolt on kit with no modifications required.

stock plug

photo6.jpg

modified plug

photo1.jpg

The Figures: the new alt is 125amp over the original 80amp item. it does weigh approximately 1.2kg more (including bracket) but it does not require any more energy (hp) to drive to produce 80amps than he original. its only when full load is required that it requires more HP to drive it.

The above has now been made into a kit that can be brought through me and if i get enough interest ill do a group buy on here.

hope you enjoy the read.

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