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MQ DIESEL V8 CONVERSION

Posted: Wed May 19, 2004 9:34 pm
by junior
Help please,change of plans once again
Just another question for those of you that may know.
I spoke to a gentlemen at DELOW automotive last week cos i would like to put a chev in me black diesel rig,but i dont want it that close to the fire wall if it can be helped.He told me to use the input shaft from a L28 gearbox as they are identical to the diesel one just longer.I can then use the L28 belhousing aswell ,this moves the motor away from the firewall a fare amount.
Just like to know if anyone has heard of this before i do my balls on it...... :D
The kit was cheap too,$850 for everything needed to do the conversion.
Thanx to all
Cheers jnr

Posted: Fri May 21, 2004 10:50 am
by Screwy
If u r using the L28 bellhousing with a special ring adapter from dellow ontop of that between the L28 bellhousing and the motor u will clear the fire wall with out having to hit it. It will still be pretty close on the rocker covers though. Your only problem will be the spigot bush and then radiator etc.
Did u ask him about the spigot bush setup?

screwy

Posted: Sat May 22, 2004 10:13 am
by V8Patrol
easiest way for a V8 conversion into a MQ diesel is.......

castlemaine rod shop bellhousing to suit nissan box and chev motor. ( around the $400 mark)

and fit a 5 spd box from mq/mk up untill 87 model .

The 5 spd will push the motor foward 135mm so firewall clearance is no longer an issue.

Sure the cost of a 5 spd isnt cheap but the long term benifits are there... like 20% less revs at 100k's, lower 1st gear, etc . It also makes the whole setup more user friendly.

other option is a Marks addaptor setup.... it pushes the motor well foward ( about 6") and uses the std box you have but the kits are not cheap.

another option is to move your box foward.... this means making new box mounts, and lengthing one drive shaft and shortening the other. you'd only need to gain about 2 inches for firewall clearance...... then again just massage the firewall !!


junior wrote:He told me to use the input shaft from a L28 gearbox as they are identical to the diesel one just longer.I can then use the L28 belhousing aswell ,this moves the motor away from the firewall a fare amount.


This means changing boxes and getting a L28 bellhousing for starters then you still have to get an adaptor for the L28 bellhousing to fit the chev. I recon it would be easier just to swap the boxes rather then stripping yours and fitting a new front shaft to suit.
Like I said .... a 5psd will fix the firewall problem instantly, then a castlemaine rodshop bellhousing to suit the chev. No stuffing around with any other bits.

Kingy

p/s
I'll post up pics if ya need some ideas when the pic option comes back online :roll:

Posted: Sat May 22, 2004 1:21 pm
by nischev
If you use the L28 input shaft and castlemain rod shop bellhousing you dont have to move anything for firewall clearance if using a chev. They dont supply engine mounts but if you are good at welding theyare easy to do as the mounts on the block line up with the original nissan rubber mounts with about an inch gap.
The input shaft is easy to change on the mq gearbox as you dont even have to pull the box apart.
I have this conversion in mine.

Posted: Sat May 22, 2004 6:21 pm
by Screwy
nischev wrote:If you use the L28 input shaft and castlemain rod shop bellhousing you dont have to move anything for firewall clearance if using a chev. They dont supply engine mounts but if you are good at welding theyare easy to do as the mounts on the block line up with the original nissan rubber mounts with about an inch gap.
The input shaft is easy to change on the mq gearbox as you dont even have to pull the box apart.
I have this conversion in mine.


got any pics at all?
I wish i did it that way as i used the same setup as u except the deisel output shaft and my firewall needed some lite massaging :cry:

My engine mounts were modified considerably also.

screwy

Posted: Sat May 22, 2004 6:46 pm
by junior
Thanx guys,its all starting to make sence now.Im getting so much different info and im getting so dam confused :x .
Kingy i need some more info from you plz,As you have said the five speed is the way to go, i totaly agree but do they mount to the original gearbox/transfer mounts as i dont want to move them if i can help it.
So at a guess ,i remove the diesel motor and 4 speed box and shafts,fit a five speed Mq/Mk box and shafts.Then purchase a Rod Shop bellhousing to suit Nissan five speed to chev.Then i make my own engine mounts to suit.This will leave the chev with a decent space behind . Correct ?
1.Did you have to move your chassis engine mounting plates also?
2. What clutch set up is best for this combo?

Im exploring all options so sorry to ask so many questions,Id also like to look into fitting a big block in it but thats looking like a fare bit of work to do and may not fit as good as a small block.Do you know if anyone has done it before?
Thanx guys for all ya help much appreciated.
Jnr

Posted: Sat May 22, 2004 6:53 pm
by junior
Yeh Nischev thats what i was told also,I asume your rig was a diesel in its prior life yes?
I have a complete L28 box handy so im trying to explore all options before i go hack on the lot.
Thanx
jnr

Posted: Sun May 23, 2004 8:47 am
by V8Patrol
junior wrote:As you have said the five speed is the way to go,
but do they mount to the original gearbox/transfer mounts as i dont want to move them if i can help it.


The 5spd is a longer box than the 4 spd, the 5th gear is housed in a "spacer"setup between the transfer and the actual box...... therefore the current box/transfer mounts don t need to be modded. The front face of the 5spd will be 135mm further foward than the 4 spd, this is how you gain the firewall clearance. PM me ya email addy and Ill send a couple of pics.



junior wrote:So at a guess ,i remove the diesel motor and 4 speed box and shafts,fit a five speed Mq/Mk box and shafts.Then purchase a Rod Shop bellhousing to suit Nissan five speed to chev.Then i make my own engine mounts to suit.This will leave the chev with a decent space behind . Correct ?

Correct but you can use your original driveshafts, the transfer will be in the exact same place and use the original mounts.
Mine was an L28 originally so I didnt have to alter anything originally.... but whan I fitted the 5spd I had to make new g/box mounts to allow for the longer g/box, I also had to make new driveshafts too.

The differance in the two nissans ( L28 & SD33 using a 4 spd ) is the diesel motor is much longer then the L28. Nissan simply moved the g/box further back in the diesel to allow room for the motor.

junior wrote:1.Did you have to move your chassis engine mounting plates also?
2. What clutch set up is best for this combo?


1.
do not have to move the enginemounts on the L28 conversion
do not have to move g/box mounts on the L28 conversion if using the 4spd.
do not have to move the g/box mounts if a 5 spd is fitted to a SD33.
do have to move the enginemounts if using a 4 spd from a SD33 and massage the firewall too.
do not have to move the enginemounts or g/box mounts if using a 5spd in a SD33

2.
Thats entirely up to you...... I use a
V8 holden flywheel redrilled to suit the chev crank
V8 holden pressure plate.
260mm Nissan clutchplate. ( I'll give out the part number later )


junior wrote:Im exploring all options so sorry to ask so many questions,Id also like to look into fitting a big block in it but thats looking like a fare bit of work to do and may not fit as good as a small block.Do you know if anyone has done it before?


The bigblock has only a couple of problems with clearance and the issues are with the bolt on accessories ...IE: exhaust manifold clearance to steering shaft ( the shaft that runs from the firewall to the steering box). These issues are realitive easy to get past.

Kingy