Engine change - conversion aspects

Dangerdoc · Post by **Dangerdoc** » Tue Apr 29, 2008 1:00 pm

Ohhh the headaches on this: -

Swapping out a 25D engine (3.5 V8 EFi Auto 9.35:1) with a 26D engine BUT it is a 3.5 V8 Carb Manual 9.35:1

The question is: I need to keep the automatic aspect and the EFi so:

Does anyone know what parts are needed to change at the crankshaft flange to accommodate the torque convertor, inertia plate, flexplate system as the diameter of the hole in the end of the crankshaft is too small.

Do I need to swap out the crankshaft or is there a more simple way?

Rocker covers: My old EFi ones are not fitting the replacement engine (carb breather system as opposed to the flametrap and air vent). Am I missing something really simple here?

The old engine has done about 70K and if anyone wants a long engine with no ancillaries they are welcome to collect if from me for free.
Thanks all.

Post by **katanaman** » Tue Apr 29, 2008 7:30 pm

I am not very familiar with the auto boxes but I can tell you the engine cranks are identical between auto and manual. You will either have a spigot bush in the bore of the manual crank or an adapter bolted to the flange of the auto crank. The adapter/spacer was used on later auto boxes.

RoverP6B · Post by **RoverP6B** » Tue Apr 29, 2008 10:38 pm

The rocker covers on your efi engine have a squared off appearance, with the oil splash panels intergral within the covers.

For the carb engine, you will need a different pair of rocker covers, either ones from a LR /RR which had carbs fitted (upto about 1985-6) or from an SD1 running carbs upto early 80s.

Or, a set from a P5B, P6B, which are of the rounded-off appearance.

If you use the rounded off type, you will also need to obtain separate oil splash panels, as these are mounted onto the rocker shafts themselves, as opposed to being part of the actual rocker covers as is the case with the later squared off design.

Ron.

Dangerdoc · Post by **Dangerdoc** » Wed Apr 30, 2008 7:24 am

Hi Ron,

Thanks for that. I have the rounded ones AND the square ones - obviously from each engine.

The breather system on the carb type covers has a different arrangement than the EFi breather system. This creates a problem as the cover vents on the carb ones have an exit stub metal breather pipe on each one that should go to each carb respectively on each side.

Not good for the EFi breather arrangement. So I was keen swap the carb ones out and fit an EFi type. I got confused when the EFi ones did not fit.

Yes the splash covers are inside the square ones (EFi) and there are splash covers on the rocker assembly with the new engine. I might remove the splash plates from the rocker assy and see if that does the trick.

I really did not think that the rocker covers would be a pain in the preverbial.

So annoying for such a simple metal cover.

ChrisJC · Post by **ChrisJC** » Wed Apr 30, 2008 7:39 pm

The heads are also subtly different - the EFi heads have small notches in the roof of the inlet tract to clear the injector spray pattern. Some folk ignore this detail with no apparent problems. Or a lick with a file would probably suffice.

Chris.

mgbv8 · Post by **mgbv8** » Wed Apr 30, 2008 8:31 pm

On my RV8 auto conversion I took the bronze bush out of the crank so the ally pilot bush for the converter would go in.
But I converted from RV manual to Chevy auto.
Might be interested in the engine though.
Where in London are you ??

Dangerdoc · Post by **Dangerdoc** » Wed Apr 30, 2008 9:16 pm

Fantastic. Removed that little bush in the end of the crank and with a tiny lick of grease and hey presto - in slips the ally inertia drum thingy ( ok it's maybe not the real name but it sounds technical and I like it

).

The cylinder heads will need a good poking at with an eyeball and I might feel brave enough to threaten by violently waving a file at it and no... not an A4 suspension one before some smart a**e gets a nip in.

Now the rocker covers are the only bit piddling me off. I (probably stupidly) thought it would be a direct swap between the EFi ones (square shaped) I have from the old engine and the Carb ones (rounded) that came with the new engine.

Every twist seems to make the thing want to make you hit things harder with an even larger hammer. Does sod all to help but sure makes you feel good.

If anyone of you wizards out there can help in sorting out this bit then I would be most grateful indeed.

RoverP6B · Post by **RoverP6B** » Wed Apr 30, 2008 10:13 pm

As you are fitting the newer squared off type rocker covers onto the engine that had the carburettors, you will certainly have to remove the oil splash panels from the rocker assemblies, else they just won't fit.

If after having done so, and with new rocker cover gaskets, the rubber ones are the best to go for, they should just fit.

The shape of the heads where they meet are identical. I have my old rounded type fitted to my 4.6 with 4.6 heads (the last casting design) and no problem at all.

Ron.

mgbv8 · Post by **mgbv8** » Thu May 01, 2008 7:36 am

" inertia drum"

I love it. Im going to my torque converter an inertia drum from now on doc.

PS
I think your old engine may do me some good now I've looked at my spare that I was going to rebuild.
i
Pm me with your location so we can talk about collection .

Regards
Perry

Dangerdoc · Post by **Dangerdoc** » Thu May 01, 2008 9:03 am

Cracks me up "inertia Drum" No no no, I am referring to the little steel mini flywheel that bolts to the flexplate and has a shaft going into the crank.

The torque convertor inputs into this and is bolted to the plate.

Jees give me some credit, I'm a medic but not completely backward with cars.

I just like calling that little metal bit an "inetria thingy" as I have no idea what it should be called.

Come on guys - what is it called

RoverP6B · Post by **RoverP6B** » Thu May 01, 2008 11:16 am

The crankshaft to flexplate spacer is a disk. The torque coverter bolts to the other side of the flexplate.

Ron.

Dangerdoc · Post by **Dangerdoc** » Thu May 01, 2008 6:35 pm

Well, got over the bronze bush and things slide into the crank Ok, thanks to the advice.

Saturday will see the rocker covers being sorted out when the oil splash guards come off the rocker assy.

Will take a little Dremmel file to the heads for the injector spray pattern.

And was planning on torquing on the torque converter and spacer assy with the flexplate together BUT .... and it is now a big BUT...

My (now ex) mate was rummaging about in the back of the rangie and disturbed all the flexplate assy and has managed to rearrange the order of everything.

I know I should have scribed it (

) but hell that didn't happen so help please for this nutter who should know beter...

What is the order from crankshaft to torque convertor for all the damn bits

Probably now have to get the magnifying glass onto the surfaces to see what lines up with what.

Lesson: Scribe everything when dismantling OR place everything carefully and don't let the thick mates near the stuff no matter what.

This should have been a simple matter.

Love it!

Of course, just like most things, the emoticons are just there to be abused.

Cheeries to you all for the advice and guidance it is really appreciated.

mgbv8 · Post by **mgbv8** » Thu May 01, 2008 7:28 pm

Doc
This is a Range Rover flex plate that I didnt need as my Chevy to Rover plate is way different.

Does this pic help?

mgbv8 · Post by **mgbv8** » Thu May 01, 2008 7:31 pm

This is my Buick 215 flex plate looks like. See the lugs welded on so it will take a Chevy box and coverter without all the other bits.

mgbv8 · Post by **mgbv8** » Thu May 01, 2008 7:33 pm

Forget the scriber. I use a big magic marker