heard back from the engine shop today.....

[datsunboy]

and apparently my head has been hot at some stage, and gone soft!Hardness test should come up over 100....and my head is only 55!so need a new one.Can anyone confirm that a DE head is the same as a DET head?
Modified by datsunboy at 9:37 PM 2/24/2005

[biosehnsucht]

The head is the same. a DE head may have EGR stuff attatched to it, you can remove it and install the plug found on your DET head. same for any other "differences", swap parts if necessary..

I've never heard of a head going soft, I've heard of them warping from overheating.. I'm not expert, just I've never heard of it... what does it mean, exactly?

[datsunboy]

yeah Iv'e never heard of it either.....but he got the tester out and showed me!

I've done a course in material strengths and proccesses.....so I guess it makes sense!....lol

He said the main problems are that it will blow gaskets, as the headbolts are unable to keep the clamping force on the head......He said he's seen some heads before, where the "bolt washer seat" has recessed itself up to 5mm into the head!!!!

he said they can also start getting the steel part of the head gasket imprinting itself into the head surface

[Dattebayo]

This IS strange. From what i know, the heads are supposed to be pure aluminum.

The only way i could account for heat changing the hardness of something would be if it was an alloy, or if it was super-heated. If it is an alloy, the heavier elements would be pulled to the center and down because of gravity and it's mass. This would change the shape of the holes for valves and stuff in there as well.

I really hope it isnt true. Maybe you should take it to get a second opinion.

[datsunboy]

thats true....I will talk to my old materials tutor tomorow, and see what he says..... ( probably...."didn't you learn anything from my class?" )...lol.

I doubt the heads are pure aluminium tho

[boost_boy]

and apparently my head has been hot at some stage, and gone soft!Hardness test should come up over 100....and my head is only 55!so need a new one.Can anyone confirm that a DE head is the same as a DET head?

In nearly 9 years of screwing the CA series motors and have dealtwith many other motors, I have yet to hear such a claim. If your head is warped, either get it machined or get a new one. Don't give your money away because it sounds like that's going to be the case.

Dee

[datsunboy]

talked to my tutor....he said that it would have had to have been heated in excess of 6-700 degrees celcius (1112-1292 fahrenheit ). Which is kinda unbeleivable in a auto engine!Maybe all CA heads are only meant to be 55 hardness?.....or maybe mine was a factory stuff up?does anyone have thier head in a shop at the moment that could get it hardness checked?Looks like I will probably just use this head now anyway.....and get another one if I start having problems....

[datsunboy]

ok, have managed to find a DE head complete for $30!!!comes with cams valves e.t.c. all assembled and steam cleaned wrapped up in a bag So will take it in to get the hardness checked ( as a comparison ), then get it surfaced.

Are the CA18DE cams any different to the CA18DET cams? If so....which am I better to use?Is there anyway of taking the hydraulic lifters out, without having to re-bleed them? ( the head has been sitting a while....so may have to anyway????? )cheers

[Xero]

where did he get this magical specification? I've never heard of hardness testing (though that doesn't mean it's not done, or not possible, or whatever)

but where the hell does he find this spec?

[biosehnsucht]

tahts a good deal for a head.

you'll need to swap over the EGR plug probably from the back of the head from your DET head, in place of the gaping hole there. And removing the EGR bits if they're actually attatched to the DE head..

cams & etc are the same, at least according to Nissan FAST US/JDM comparison. it will bolt on, as long as you plug that EGR hole.

[fraz]

He's in New Zealand, so the engine will either be a nz market one or a jap import and neither have the egr setup.

The exhaust cams are all the same, but the turbo intake is a little smaller than the N/A, so just keep the cams in it.

[biosehnsucht]

Forgot about that, good point. in which case it should already have the EGR plug in place, unless the head rebuild place ditched it (doubtful)

The cams should be the same, unless he has some freak head. AFAIK only CA1xDE cams difference is the non pollution control version CA16DE in europe that has a 'hotter' (slightly) intake cam, and the rest are identical. AFAIK, and I know JDM, EDM, and USDM cams are all the same in FAST excepting the above mentioned model.

[datsunboy]

yep, no EGR stuff so use the cams wih it?and any ideas on the hydraulic lifters yet?I have a mate who builds Diesels, and he said not to bother....they'll tick for a minute or so, then quieten down....

[cortina-mk1]

keep your lifters in order as in ...always put the same lifter back on the same lobe it cme fromyou dont have to do much more with them they should be fine
Modified by cortina-mk1 at 10:53 AM 2/28/2005

[float_6969]

Not to say your wrong, by why does it matter if you don't put a hydraulic lifter back in the same place? I could understand that on a solid lifter setup, but with a hydraulic, I don't see the point.

[cortina-mk1]

yes you are right float on a solid cam it i a mustbut we have always liked to keep them in the same spot it just eliminates the wondering later on if a light top end noise develops