FWD vs RWD

[Mr_Efficiency]

I've seen a lot of threads on this latley and im curious myslef and cant seem to get an answer.
What is the diffrence between a fwd and rwd block?
I have been looking at pictures of rwd blocks and comparing them to a fwd block i have in my garage and they look pretty much the same with the exception of the front timing and pulley assembly.
Is that the only diffrence?
What is stoping me from puting a fwd motor in a rwd car?
I used to think it was cause the bosses for the motor mounts werent there but they are so in theory it should bolt in so where is the problem?
thanks

[bszopi]

Look at the mounting for the starter. There is one problem... And besides, all RWD engines are old technology, hence the reason so many RWD guys are swapping on FWD topends.

[Mr_Efficiency]

whats the problem with the starter?
I dont have a rwd block to look at just pics and i cant make out the starter bolt holes in any of them so its hard to tell.

[bszopi]

The starter is on the opposite side. So you would have to drill the block to get the starter on the proper side of the engine. The newer (Gen 3) blocks also have a much better oiling setup than the older (ie, RWD) blocks.

You can also read up alot on the 2 engines in the Family tree... http://60degreev6.com/content/60%C2%BAV6_Family_Tree

[Mr_Efficiency]

Yeah i plan on using a newer block in a rwd aplication....

Just tap new starter holes is all i need to do? thats easy enough I was expecting something a lot more complicated.
thanks

[bszopi]

Looking back at your previous post, you mentioned motor mounts. I think there is a slight difference in location as well as number of holes between the FWD and RWD blocks, therefore either custom or modified motor mounts may be required.

[ForcedFirebird]

In a RWD config, the pass side mount has to be custom. The starter move isn't that easy I wish it were "just tap som holes" lol, there's not a lot of meat there to tap. Also the oil pan becomes an issue, it hits most frames.

The timing cover is interchangable, you will need to close up the extra water passage on the driver's side of the RWD cover to use on a FWD.

[Canyonero]

Which side would the starter end up on in a RWD application? Troopers have the starter on the drivers side anyway. If it's just one side of the motor mount that needs modified, then I'm putting a FWD block in my Trooper! I thought there was more to it.

What about Gen. 3 vs. Gen. 4, did the mounts change? Can I stick a 3.5L in my RWD Trooper with little hassle?

[ForcedFirebird]

Which side would the starter end up on in a RWD application? Troopers have the starter on the drivers side anyway. If it's just one side of the motor mount that needs modified, then I'm putting a FWD block in my Trooper! I thought there was more to it.

What about Gen. 3 vs. Gen. 4, did the mounts change? Can I stick a 3.5L in my RWD Trooper with little hassle?

You also have to deal with the oil pan.

Here's pics of the difference between the gen 1 and gen 3 oil pans...

http://s158.photobucket.com/albums/t87/forcedfirebird/Gen1%20and%203500%20oil%20pans/

[Canyonero]

So even with the front cover changed, the oil pan is not interchangable? I have a 4x4 oil pan anyway... Is there something special about an oil pan that would prevent someone skilled with a TIG welder from chopping one up and reforming it into the desired shape? I need the deep sump at the back to clear my front axle.

[geoffinbc]

You could mod the pan if you wanted to.

[WrathOfSocrus]

Not sure if this helps but

http://www.killerbv6.com/pictures.html

The have timing covers with mounts on either side from TCE for mating a FWD engine in an MGB. On their front page it says it can be used to make any pushrod 60v6 to work in most RWD applications.

Sure you would have to fabricate mounts on the frame side, but you sure wouldn't have to worry about the engine side of the mount coming apart on you! I have been giving this some thought as I know of a few people with beaten 90*V6's about to junk their trucks. A 3500 powered S-10 or something similar would be a lot of fun to drive!

[ForcedFirebird]

The RWD timing cover works fine with the FWD oil pan, you just need to fill in the extra water passage that goes to the outside of the block on a FWD. The bottoms of both covers have the same radii and interchange.

I'm planning on modding a 3500 oil pan I have exacly how you are thinking.

That's right, the Trooper already has the starter on the driver's side, doesn't it?

So a modded oil pan, custom motor mount and timing cover with the hole fille, a FWD block should go in yours much easier than others. The only problem I might see is that you may be cutting out the extra cross-bolts into the main caps on the FWD with as shallow as the front of your pan is. You want to keep them if at all possible.

For the 3500, you will also need the external DIS trigger.

[Canyonero]

I have most of the parts for doing a 3400 top end swap, but I was just thinking about maybe buying a whole 3500 instead of getting a new 3.4L bottom end to work on. Then I can pull the 3.4L I have already and do the 3400 top end for another car/truck.

[Mr_Efficiency]

why does the timing cover have to be changed? cant you use a fwd timing cover and accesories in a rwd application? the only problem i see is you would have to make some custom brackets to mount the power steering cause the throttle body would hit it when you flip the UIM around.