Differences between TB42 Carby and TB42 EFI???

[mattsluxtruck]

Hi all
A mate of mine is looking at grabbing the old TB42 out of my maverick to rebuild it for his Patrol so he does not have to take his off the road.
My TB42 is a carby. His is EFI.
We are aware that the heads are different and aware that you can only get the EFI head casting from Nissan now and they are interchangable.
The question is another person has stated that the entire motor is totally different between the carby and efi model.
Can anyone either confirm or deny this statement?
Cheers

[jessie928]

same head, same block, same everything.
just the injection manifold is different.
you need to stay well away of whoever to you teh engines are different


Jes

[PGS 4WD]

Jes is correct although I beleive the EFI camshaft is slightly bigger, your friend might be thinking of the TB45 vs the TB42 where heads and camshafts and distributor drive gear and on on are different.

Joel

[RN]

Jes is correct although I beleive the EFI camshaft is slightly bigger, your friend might be thinking of the TB45 vs the TB42 where heads and camshafts and distributor drive gear and on on are different.

Joel

So would an EFI manifold bolt right on a carby head no worries then???.( straight gas)

[jessie928]

Jes is correct although I beleive the EFI camshaft is slightly bigger, your friend might be thinking of the TB45 vs the TB42 where heads and camshafts and distributor drive gear and on on are different.

Joel

So would an EFI manifold bolt right on a carby head no worries then???.( straight gas)

yep everything is the same/interchangeable.

[jessie928]

Jes is correct although I beleive the EFI camshaft is slightly bigger, your friend might be thinking of the TB45 vs the TB42 where heads and camshafts and distributor drive gear and on on are different.

Joel

hmm, i would have to check a couple of the cams i have to confirm this.
maybe there is a cam profile difference between early and late engines aswell ( carb or injection aside)

Jes

[PGS 4WD]

That is also possible, I know the early Patrols had camshaft failure issues, I replaced a number under warranty as an apprentice at Nissan in the early 90's, many failed prior to 40k.

I coverted a vehicle for Henry at Pro Comp Vic a number of years ago from carby to efi turbo, it all bolts straight on, no worries.

Joel

[BowTieGQ]

EFI had a slightly different cam. Head casting is only a little thicker along the valve line where they are prone to cracking, but remain identical apart from that. Any other differences will be the likes of hoses as they will be going to the different inlet. Fuel pump block off plate. Induction plumbing. Bigger amperage alternator but not sure if the same brackets, but that wont matter to you as you have them.

[brads4wdmad]

Jes is correct although I beleive the EFI camshaft is slightly bigger, your friend might be thinking of the TB45 vs the TB42 where heads and camshafts and distributor drive gear and on on are different.

Joel

So would an EFI manifold bolt right on a carby head no worries then???.( straight gas)

yep everything is the same/interchangeable.

Just got off the phone to a few Engine rebuilders and Head engineers and was told the same by all of them

The TB42s (carby type) have different heads and that the bottom end is only the same as the TB42e (Efi type)
was stated to me that you cannot use the head from a Tb42s onto a Tb42e
as i was wanting to get the TB42s and have it rebuilt and still have my TB42e on the road

Can anybody dispute this at all or is it definatley correct

Thankyou
Brad

[Fozdick]

TB 42E has a oil cooler on the side of the block (jap diesel style)

TB 42S has a blanking plate


Shaun.

[PGS 4WD]

If there is a difference it is internal or casting and has dosen't effect the bolt ons so you can rebuild your carby motor and bolt the EFI on. I have done this on a number of occasions. Most head shops weld the crap out of all the suspect areas on the carby heads anyway. The main thing is to get a rockwell hardness test on the head you are rebuilding as they go soft if cooked enough, they can be rehardened but it is a largish job as the guides and seats all get loose and need replacing due to the hardening process.

Joel

[MyGQ]

TB42S and TB42E heads work fine on each other, the TB42S head though has a Compression ratio of 8.3:1 where as the TB42E has 8.5:1, bit extra power.

The bolt pattern is the same, the manifold stud patterns are the same and the pushrod system is the same, there is very little difference that prevents them going on.

if your going straight gas just use the TB42S and throw a EFi manifold on it, block off the Injector ports and leave it running the dizzy to do the timing and screw the ECU setup.