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3.9 to 4.6 1995 NAS D-90

Posted: Thu Jan 26, 2006 1:02 am
by boxerhips
I just picked up my newzed 4.6, and I like the black intake(GEMS). I think I have 5 options. 1- use the 4.6 intake w/3.9 front cover(check or change water and fuel temp sensors) and change cam 2- use 4.6 intake w/3.9"B" front cover same as #1 plus buy Disco ancillaries 3- use 4.6 intake, front cover, and cam buy 4.0/4.6 ancillaries convert to EDIS/Megajolt Lite and still use 14CUX 4- same as 3 , but use Megasquirt instead of 14CUX 5- use all 3.9 junk I know it is much less painful just to use the short block from the 4.6, but I like the 4.6 intake. ?'s I have with EDIS how do you install the 36 to 1 ring(weld or bolt to front of crank) and can I use my a/c, PS, and Alt with 3.9"b" or 4.0/4.6 ancillaries? Do I have to install spacer with 3.9 covers(D-90 or the "b")? Thanks Tim

Posted: Thu Jan 26, 2006 10:58 am
by RangingRover
why not just spray the 3.9 intake black?

Posted: Fri Jan 27, 2006 12:51 pm
by boxerhips
Its more than I want it black. I would love the lose the dizzy. I think I want to use the EDIS setup.

Posted: Fri Jan 27, 2006 5:51 pm
by RangingRover
ahhh - in that case, I think you'll need to use a 4.6 front cover, for the cam sensor.....

Posted: Fri Jan 27, 2006 6:42 pm
by justinC
And the camshaft and sprocket from a GEMS 4.6 aswell....The cams are different in the way they mount to the cam gear etc etc, and as far as I know hard to get in OZ as a performance grind.

Posted: Fri Jan 27, 2006 7:18 pm
by Loanrangie
At a guess i would say he's not local, V8 D90's are as rare as rocking horse poo !

Posted: Fri Jan 27, 2006 8:57 pm
by justinC
youre right, loneR, I should've spotted that obvious inclusion!!!

Posted: Sun Jan 29, 2006 2:52 am
by boxerhips
You're right, I'm in the US. Its just most US rover forums are limited to there Rover egos, and would/will not change from Rover electronics. So I come here for "open" opinions. I would like to install EDIS. The research I have done so far leads me to Megasquirt. I believe it will be alot easier to us, than say a GM PCM or a Ford EEC-IV or V. I would love to use an EEC-IV. I have a Mustang with a 21lbs Procharger whitch has a surging problem, so any thing I would buy to do the 4.6 install could help with the Mustang. So thats my dilemma. I have found somebody that has tried using a Ford EEC on a 215 olds and had problems, he is in the middle of installing the MS. Thanks for the replies. Tim

Posted: Sun Jan 29, 2006 8:24 am
by Loanrangie
Hi Tim, there are a few guys with MS on Rangies here not sure about the edis as its not a common setup. Most stick with the rover electronic dizzy and a few have fitted a GM HEI off a Buick 350 or modded V6. Edis seems to be a popular conversion in conjuction with MS. I guess you would have already been visiting the MS EFI forum ?

Posted: Mon Jan 30, 2006 4:25 am
by boxerhips
I would use the dizzy out of the 3.9, but would have to purchase front cover, cam, and lifters. I can buy all the EDIS and Megasquirt parts for less.

Posted: Mon Jan 30, 2006 4:27 am
by boxerhips
I just removed the heads from a 4.6 that I was given and there was anti-freeze in all pass side cylinders. The engine was removed for loss of compression. The waterpump shaft came off while driving on highway. I was told the driver pulled over as soon as it happend. The drivers side is fine. When I check the heads with a straight edge there is about a 1-2mm gap in middle, also the middle head bolts were really tight. The block does not appear to have drop a cylinder sleave, they are flush. None of the cylinders look stream cleaned, they all look the same. I've had a head gasket go before and you could see a noticable leak from water to piston, I can't fine anything on this engine. Should I have heads pressure tested? I don't have to use they, but that might tell me if the block is good. I've heard the heads never crack, just warp, is this a correct statement? The engine oil and insde the block looks fine. Is there a way to check block? Tim

Posted: Mon Jan 30, 2006 8:06 am
by Loanrangie
Doesnt sound good, my money would be on liner/ block problem maybe get it x rayed ? Heads should be good with just a light skim, i have never heard of them cracking. The 4.6's were notorious for overheating, dropped liners etc so possibly it was just a quality control issue and the block deck wasnt machined correctly and wasnt flat.

Posted: Mon Jan 30, 2006 9:20 am
by Philip A
I am a little confused by all your options.
1 if you want to use EDIS, a 4.6 flywheel/flexplate has I think a 60 cog signal generator and a hole in the LHS of the block for the sensor. The obvious thing to do would be to use the 4.6 flexplate and sensor. I do not see how you could easily run the fuel from a 14 CUX and the EDIS for ignition as you would need a signal from the coil to tell the 14CUX the revs. I am sure there are conversion boxes around but =money.
2 so the answer is probably a megasquirt if you want EDIS or somethibng like Microtech if you want a bit easier setup.
3 Why do you have expense for 3.9 bits if you already have a 3.9? the obvious thing is to use all your front end bits.
4 the 4.6 manifold should fit stand alone, although I do not know whether the TPS is the same as a 3.9, if you were to run the 14CUX and 4.0 manifold. that is the only issue I can think of.
5 In your shoes I would set it up to run on the 3.9 front end with distributor etc , then convert it to megasquirt, then later to EDIS. You can do this by installing the 4.6 flexplate and sensor but not connecting it until you need it. You would have far fewer variables to consider at each stage with less chance of Murphy's law catching up with you.

Regards Philip A.

Posted: Mon Jan 30, 2006 12:01 pm
by boxerhips
If 1 cylinder had anti-freeze I would think dropped liner, but the pass side of engine (all 4 cylinders) had anti-freeze. What is the normal amount the heads should be warped? There is a "black box" for the EDIS it's called Megajolt. I'm leaning towards Megasquirt, I just wish a Ford EEC-IV would cost less(because I have a surging Mustang) and I think whatever I buy for the Rover would help with this. Tim

Posted: Mon Jan 30, 2006 12:11 pm
by Philip A
Seeing that the coolant in a V8 only flows at the ends, I think you spilled coolant into the cylinders as you took off the heads.
If it was not completely empty, some may have run down the gasket into the cylinders when you loosened the head bolts. It is quite common to spill coolant into number 7 or 8 from the rear passage with the engine in the car. Maybe you tilted the engine a bit as you loosened the bolts. Several litres/pints of coolant stay in the block unless the drains within the engine mounts are opened.Either that or the engine has a very major problem!!!!

regards Philip A

Posted: Mon Jan 30, 2006 12:16 pm
by Loanrangie
I think it was given to you as a nice coffee table !

Posted: Tue Jan 31, 2006 3:11 pm
by boxerhips
Just had block and heads checked. The heads are warped .016-.018" and the block in under.002" and no dropped/moved sleeves. I'm having the heads pressure tested $70 usa. If good I will have them shaved and valve job. Tim

Posted: Tue Jan 31, 2006 3:20 pm
by Philip A
That is an ENORMOUS amount of warpage. You will probably have to shim the rocker posts. (n and it also begs the question of just how hot did the motor get?)
What CR is the motor? if its 9.35 then you will have about 9.6-9.8 if say 20 thou is taken from the heads. maybe measure the combustion chamber volumes and grind out enough to get back to 28CC or you will have to use high octane gas to avoid pinging. You can unshroud the inlet valve with the old die grinder.
Or alternatively try to find thicker head gaskets .
Of course if its 8.13 then forget all that
regards Philip A

Posted: Thu Feb 02, 2006 3:42 pm
by boxerhips
The 9.35 to 1, is that with the composite head gasket? The machine shop I went to said that all Rover heads are warped at least .006-.008 and he goes up to .020. But I know I'll have to shim the rocker post or have a cam's base circle changed. I' ve heard that if you order a custom ground cam it will cost the same. That seems easier than shimming the rockers. The engine has 70,000 miles but the cam,lifters look ok. Tim

Posted: Thu Feb 02, 2006 7:53 pm
by Philip A
All 4.6 have composite gaskets so yes.
Accepted wisdom is that the base circle on the cam is too small to have it any smaller..
its easy to make up shims out of brass stock. just remember the slot for the oil passage.
At 70,000miles replace the cam and lifters. If you buy Iskerderanian 202-HY you do not have to shim as they can stand more preload without pumpup.
Regards Philip A

Posted: Sat Feb 04, 2006 4:12 am
by boxerhips
I have a set of Isky 202-hy's, cool. Are you sure the 9.35 to 1 is with the head gasket. I find it convenient/strange that Rover 3.9/4.0/4.6 all have the 9.35 to 1 ratio engines(even when they changed from steel to composite head gasket). The heads are the same, so do you think when the designed the 4.6 (Bore/stroke change ) they took this into account? If you take the crank, rods, and pistons from a 4.6 and install them into a 4.0 will the compression be 9.35 to 1? Thanks for the replies Tim

Posted: Sat Feb 04, 2006 4:24 pm
by Philip A
The bowl in the piston is changed to make the 4.6 to 9.35:1 . According to Range Rovers .net all NA were 9.35:1.
Believe it. The heads are all the same basic design. 4.0 and 4.6 heads have about 40 thou shaved off to compensate for the composite gasket vs the tin gasket, so the volume of the combustion chamber plus gasket is the same on all Rover varients ie 3.5, 3.9, 4.0, 4.6.

If you are unsure whether you have tin or composite heads ie 3.9Vs 4.0 or 4.6, measure the volume of the chamber . For a tin head it is 35CC for a 4.0/4.6 it is 28cc, with spark plug in, and chamber covered with perspex, and kero dropped into a hole in the perspex.( to negate surface tension.)

Any changes in compression ratio are made by variances in the bowl volume of the pistons, and I believe in the deck height vs the block deck.
If you put a 4.6 crank and pistons in a 4.0 block , it is therefore logical that you will have 9.35:1.( before your head shave)
Regards Philip A