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Posted: Sun Aug 29, 2010 9:46 am
by Damo
Callumgw wrote:nice summary Damo,

I never remember which is 1 and which is 4. The second from the dizzie, third from cam belt is the excessively damaged one and the burn crown is right next to the dizzie.

The first ring is a long way down from the crown, I'd be surprised if it pinched. There is spalling on the skirt of one of the other pistons and that ring had failed there, so that still consistant with your approach. That piston looks clean and nice on the crown though....but had a valve mark

Could the cam be badly ground? with too much height and too sharp an open radius?

C

All good.

The front of the engine (#1) is at the balancer, and #4 is closest to the gearbox in 99.9% of all engines.
You will (should) also find that the little dimple mark in the pistons will be oriented toward the front of the engine, and the stamped numbers in the rods should face the exhaust side of the engine. These two a sure fire way to tell if a hack has assembled the engine or not.

I pulled down one of my engines which had a fairly heavy valve to piston episode, and it had pinched and broken 2 out of 4 piston's rings.
And another spares engine I had, had a semi melted piston and the rings from one had smashed the side of the piston land like someone had gone it with a cold chisel. Another two had fragments of rings no bigger than 2mm fall out like grains of rice under the 'pinch'.
That will only happen with cast rings though.

A cam with very steep closing ramps will tend to bounce valve more reddily with soft springs, but the cam you have is a stocker isn't it?
The only time I have had it happen is when the box used to jump out of fifth under full load, gets a buzz of 8k and the damage is done. And that was just with old springs. The other one I had was when I used a head from a burnt wreck. The high temperature of the engine fire had softened the tensile steel, and the first big over rev it had it bent a couple of valves.

Also, if the block has been decked a couple of times and the head skimmed, you end up with less 'room to move' as far as having a later closing exhaust valve or clearance in the event of a over rev bounce.

You can actually measure the amount of valve clearance you have with the engine fully assembled, by winding the engine over to 5BTDC, and slowly screwing down the exhaust valve adjuster till you fell the valve head touch the piston. My engine machinist recommends no less than 60thou (1.5mm) to be safe. For my combo, I had to do some whacky things to get my 1.5mm! :roll:

Also too, when I was suggesting a sticking wastegate, I was implying when the turbo had been heat soaked and at a good few hundred degrees after a continuous boosting, that the wastegate becomes sticky and when snapped shut on the down shift, temporarily sticks closed.



Damo

Posted: Sun Aug 29, 2010 4:47 pm
by Callumgw
the cam is not stock in that engine, but dont know what it was....

Weve had fires in the back of aircraft and to get to soft steel, your aluminium would first be cactus and a head with soften cam would have terrible ally.

I checked one of the impacted pistons and the rings are all free moving, but the ones with wear on the skirts are jammed and broken.

This engine never saw more than 6500rpm, because of the limiter and i hadnt sat it on the limiter.

but re-reading your first post (your prediction) it seems to cover off on the failure sequence well. with #4 showing crown burn and #3 burning through and #2 with skirt wear and ring failure.

This build the guy will index the cam and variable cam pulley and balance the bottom so hopefully this'll be all good. add in the haltech and bingo! reliability I hope.

c

Posted: Sun Aug 29, 2010 10:45 pm
by japcrap
hey Callum just curious about your rev limiter because i want one as well. any details on it? thanks

Posted: Mon Aug 30, 2010 7:13 am
by Callumgw
it's the Jaycar kit with shift light kit., works by cutting spark. worked OK over the time.

I think the Haltech will have a limiter in it, so might not need it when I do that update, but don't think it has a shift light so might still want that bit...not sure.

C

Posted: Mon Aug 30, 2010 9:24 am
by Callumgw
Found this on NissanExa.com
Beatle wrote: Below are the nominal dimensions of a 1988 N13 CA18 EXA power steering unit. I recently had mine reconditioned and took these measurements when I removed it. You will of course still require a wheel allignment but the dimensions are not far out.

Total Length, Centre to Centre of Tie Rod Ball Joints = 1248mm

Minimum Dimension - DRIVER SIDE:-
Centre of Tie Rod Ball Joint to Intersection of the Pinion Body and Rack Body Centrelines = 386mm

Maximum Dimension - DRIVER SIDE:-
Centre of Tie Rod Ball Joint to Intersection of the Pinion Body and Rack Body Centrelines = 516mm

Minimum Dimension - PASSENGER SIDE:-
Centre of Tie Rod Ball Joint to Intersection of the Pinion Body and Rack Body Centrelines = 732mm

Maximum Dimension - PASSENGER SIDE:-
Centre of Tie Rod Ball Joint to Intersection of the Pinion Body and Rack Body Centrelines = 862mm

The above minimum and maximum dimensions were taken with the rack extended to its maximum extension in each direction. The following dimensions were taken from the Centre of Tie Rod Ball Joint to Intersection of the Pinion Body and Rack Body Centrelines, with the rack in its centre position, that is with the steering wheel and pinion spline both rotated to their central positions.

DRIVER SIDE = 451mm and PASSENGER SIDE = 797mm
so now we can measure ours up and see if the n13 fits and figure if it's faster.....

C

Posted: Thu Sep 02, 2010 7:28 am
by Callumgw
Ohh, also worth mentioning about when I pulled the engine out and dropped the gearbox oil. The was very little wear particles, just similar to what came out last oil check (no phantom grip then), so the diff is doing OK at this stage.
The was a little metal sludge on magnetic plug, but that was all.

C

Posted: Thu Sep 02, 2010 4:42 pm
by Damo
Callumgw wrote:Ohh, also worth mentioning about when I pulled the engine out and dropped the gearbox oil. The was very little wear particles, just similar to what came out last oil check (no phantom grip then), so the diff is doing OK at this stage.
The was a little metal sludge on magnetic plug, but that was all.

C
Sweet!


Damo

Posted: Fri Sep 03, 2010 7:17 am
by Callumgw
but mine is definitely made from steel.....

C

Posted: Mon Nov 01, 2010 12:23 pm
by Callumgw
Just back from 7 weeks around Europe and stop-over in Hong Kong. Car work will hopefully start soon...I got the engine back from the builder before I left.

Intentions are to figure a new quicker rack,
Look at developing an adjustable rear proportioning valve
install Engine
install Haltech

but also gotta paint the outside of the house...

C

Posted: Mon Mar 21, 2011 7:29 pm
by Callumgw
Alrighty! Got the faster steering rack in....(check the tech articles section)

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now started on the Haltech, before re-installing the engine and finishing the Haltech.

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C

Posted: Sat Mar 26, 2011 8:38 pm
by TurboZ.Dude
Nice, the steering rack seems to fit very well! Planning to fit a P/S rack to my N12 (but I'll retain the power steering)... I'll have a look at your tech article. :)

Posted: Sun Mar 27, 2011 8:10 am
by Callumgw
clearance will be a BIG issue the pipes at the rear of the N13 rack will foul the firewall unless you mount is forward a lot. You'd be better to find a proper N12 rack if you can, but they are almost impossible to find here. From memory the only one I know was on the convert exa..... maybe Kane (who now owns them) can help out with some pictures....

C

Posted: Mon Mar 28, 2011 11:49 pm
by TurboZ.Dude
Thanks for the tip C, if the issues are that big I won't even bother to try the N13 rack!

I'll probably have to consort the U.S. markets to get a LHD N12 p/s rack... I don't think they sold p/s LHD N12:s in Europe. If I've understood correctly, at least the U.S. N12 Pulsar NX had power steering as standard equipment on A/T E16 (or was it E15, don't remember) models.

Posted: Sun Jul 03, 2011 7:05 pm
by Callumgw
Some updates, been doing the HAltech wiring, slow, but steady. I'd dropped the engine in lightly to get all the placements right, then poped the engine out again.

Rebuilt the turbo:
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Made a new wastegate bracket for the new wastegate:

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Had new oil line made, so the 'soft link'can be replaced if it chafs:

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The eninge side uses a metric 12x1.0 threaded pipe nut. The turbo end uses a 7/16 x 24 "brake tube nut".

Then today, popped the engine back in:

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C

Posted: Mon Jul 04, 2011 12:36 pm
by baz
That style oil feed is what all people need to do if they cant afford a braided line :\