78 CJ Engine Conversion

[Mousebndr]

Anyone done a conversion from the stock I6 with the TH400 trans. to a chev or GM engine?

Where can you get the adaptors here in Aus?

Cheers
Dave.

[AussieCJ7]

Hi Dave welcome

I have not done a engine conversion but have looked into it a bit

I have an 83 CJ7 with a 4cyl so very under powered

You can get adapters from Mark's adapters they are an agent for Advance adapters

The best source of info I have found for engine swaps has been Wyanes World of conversions He is in Qld and specialises in CJ engine conversions and Tony at USA 4x4 he has had a CJ with a 350 chev in a couple of mags

As to your case with the turbo 400 is yours a quadra trac ? If it is I think you will find that will complicate things a bit but call the 2 places above and ask them they know the details as they have done it maybe even get a quote it could be easier to let them do it

[MC4X4]

Dave the engine conv are very easy on cj7 because you can buy everything and it most of it is bolt in. The easyest v8 conv is a rambler 360 (jeep 360) it will bolt up to your t400 and you will just need to change your engine mounts. Now if you want to run a chev you will have to either buy an adapter plate or change the casing of the t400 from a jeep back to a chev.
I have ran booth a rambler and a chev and much prefer the chev
mc

[cj5350]

Be real careful of the price from marks. I was quoted twice as much as what steve from mascott
ended up getting it for me..

CJ5350

[Steve]

I'd say if you're gonna do a swap definately go Chev. Loved the 350 I had in my old truck in the US! Hell go all out and see if you can shoehorn a 454 in there! ;) I had a mate that had a turbo charged 350 in a Willy's and did 9 second quarter miles in it! Lucky he had an old man that was a pro funny car driver! Lots of mechanics at his disposal!

But seriously you are dead right about the Chev motors. Much more available for them and heaps cheaper to rebuild. And the POWER!!! :eek:

[AussieCJ7]

Hey MC why did you prefer the chev ??

I like they idea of keeping it all jeep but the $$$ make a chev look like a better option and you can get parts almost anywhere

I also like the idea of an EFI 302 matted to a T18a

[MC4X4]

Money is a factor, but i got rid of my 360 and went for a chev so i could run a t700 4spd auto, and the performance parts you can get for a chev.
I rebuilt my 360 once and it cost twice as much as a chev rebuild.
I have never like fords but the efi 302 is a good motor
I am putting in a order to the states for a fuel injected manifold to do on my 383
MC

[TW.]

the G.M. small block is a good thing, espessially over the AMC motor.

we have mounts ustilizing a AM-8/360 mount and are fully engineerable to suit a CJ installation, and as said you need to swap the TH400 case to a G.M. pattern and the rest is prety simple.

one thing you'll find is pre 81 CJ's need have some surgery on the fire wall by an inch or move the quady/auto/motor forward an inch & mod tail shafts to fit a chev in with a HEI dizzy, if your happy to run a points unti it is not needed, same if she's 81+.

[cj5350]

Another thing is speak with your engineer and get him/her on side first...no point doing the job twice because of where you welded the mounts on the frame or that the motor was to old to meet the polutions laws for the age of your truck..eg
If your truck is a 80's model...no point getting a cheap HQ (70's) for a doner engine unless you go full gas etc..
Also speak with guys who have done it before such as USA4x4..
things like short water pumps, thermo's, doner cars for bits like radiators etc, even placement and offset advice can save you a lot of time..

good luck

CJ5350

[Mousebndr]

Well.. after much calling around I decided on a GM 253 - not the biggest V8 in the world but...

Picked one up cheap from a wrecker.

Anyone who wants to do a conversion... The guys a Dellow Auto are the people to talk to... very helpful.

Fingers crossed everything will go fine smile.gif

[Steve]

Originally posted by Mousebndr:
Well.. after much calling around I decided on a GM 253 - not the biggest V8 in the world but...

Picked one up cheap from a wrecker.

Anyone who wants to do a conversion... The guys a Dellow Auto are the people to talk to... very helpful.

Fingers crossed everything will go fine smile.gif <font size="2" face="Verdana, Helvetica, sans-serif">I think you'll still be happy with that in a jeep. Mate has one in his Holden Ute and she still go like hell! All the best! Keep us updated on the progress!

[Brick]

mousebndr

how did the 253 conversion go

[Wooders]

Brrr....Sorry Mousebndr & no offense intended to you on this - but I'm not a big fan of the 253....
The chevy is a good choice becuase of the cost and the availability of all sorts of parts at reasonable costs - BUT be aware that some insurers are now excluding Chev engines - eg TCIS won't touch you with a petrol Chevy (ask Dawson)....
The AMC can be made into a great donk and it's more "Jeep" - but expect to pay more (sometimes MUCH more) for the preveledge....
Holden V8's - now I'm not a Ford or Holden lover...I love my Jeeps and no other brand...The rest I can appreciate their good and bad but I have no loyalty.....Now as I said at the start of my ramblings IMHO the 253 is a dog of a donk (maybe with fleas it's better ;) )....It's a fairly gutless motor, is inefficient and overall just not my cup of tea.....Instead I'd be looking at a 308 as a starting point....MUCH better :D
Ford V8's can be found cheap, the efi is nice but as I understand can be a bit hard to fit height-wise. I understand anyone with a Holden background is going to struggle to approve this one...But IMHO mated to say a C6 tranny it would be a good setup.
Right now I'm still looking about for a donk for my wagon and too be honest the Ford & Holden donks in the 5.0L range are leading the pack....

[ 17 January 2003, 03:36 PM: Message edited by: Wooders ]

[Mousebndr]

Hi All,

Conversion went pretty smoothly ... as much as a conversion can go smile.gif

Had to make a modification to the bellhousing on the TH400 (to accomidate the 253 starter being on the passenger side), manufacture a new tin belhousing front cover and put in a new accelerator cable (used an old holden cable). I also modified the acceltorator pedel a bit - not sure if this is nessisary or if mine was stuffed.

But apart from that everything went pretty smooth.
Runs like a rocket now though - Certainly heaps more power and better fuel economy than the old Jeep I6.

I also put a mallory electronic disy & coil on it, gutted the carby a little and added a 2.5" exaust.

Were going upto Sunny Corner this weekend to give it its christening so we will see how it goes offroad.

BTW if your going to do this.... your prob going to have to modify your firewall a little on the passenger side - do it first, it sucks to have to take the engine out again lol.

[Mousebndr]

Your right about the 308 Wooders, bit more grunt there smile.gif

Good thing about the 253 though is that technically it dosnt exceed the RTA's 15% power increase guidelines + you can slot a 308 on the same mounts and box easy later on.

Having said that though, this 253 goes like the clappers with the mallory ignition and the modified carby - just make sure you have a radiator shroud!

Originally posted by Wooders:
Brrr....Sorry Mousebndr & no offense intended to you on this - but I'm not a big fan of the 253....
The chevy is a good choice becuase of the cost and the availability of all sorts of parts at reasonable costs - BUT be aware that some insurers are now excluding Chev engines - eg TCIS won't touch you with a petrol Chevy (ask Dawson)....
The AMC can be made into a great donk and it's more "Jeep" - but expect to pay more (sometimes MUCH more) for the preveledge....
Holden V8's - now I'm not a Ford or Holden lover...I love my Jeeps and no other brand...The rest I can appreciate their good and bad but I have no loyalty.....Now as I said at the start of my ramblings IMHO the 253 is a dog of a donk (maybe with fleas it's better ;) )....It's a fairly gutless motor, is inefficient and overall just not my cup of tea.....Instead I'd be looking at a 308 as a starting point....MUCH better :D
Ford V8's can be found cheap, the efi is nice but as I understand can be a bit hard to fit height-wise. I understand anyone with a Holden background is going to struggle to approve this one...But IMHO mated to say a C6 tranny it would be a good setup.
Right now I'm still looking about for a donk for my wagon and too be honest the Ford & Holden donks in the 5.0L range are leading the pack....<font size="2" face="Verdana, Helvetica, sans-serif">

[Wooders]

LOL fair nuff mate.
I've seen a few 253's that go hard - but the sterotype norm is graemlins/sleep.gif
Also can fully understand the engineering displacement limits - That's actually a big factor that I'm considering with my engine selection for the wagon....

[OzJeeper]

When my Rambler motor in the CJ6 ran a big end bearing, I decided to replace with a Ford 250.
Went ahead and did the conversion thinking I won't need an engineers cert.
The old "6" picked up here skirts and ran well with the Ford transplant - and ran cheaper than the Rambler - by far!

Got caught though. Had to have it engineered as the motor was more than a 10% increase in power.

I think a V8 would have snapped the 6 chassis.. graemlins/crying.gif

[ 23 January 2003, 01:03 PM: Message edited by: OzJeeper ]