6M Differences

[Supra Bob]

Aside from the longer stroke (and the things that go along with that, i.e. rods and wrist pins etc..), what, exactly are the differences between the 5M and 6M.

I know the injectors are the same 182's. Is there any difference in the heads/valves/cams/intake, or is it simply just a matter of longer throw?

[SilverMk2]

Different..

rods
crank
engine block (3 extra cutouts)
crank pulley
ac bracket
engine mounts
upper manifold (& lower for 82-83 + 84 auto cars)
TB
oil pump and oil pan
distributor has a different part # than the 85 unit

thats all that I remember on mine.

[CJSREDPRA]

Bob,

The 6M head is basically identical to the 5MGE head. Not much changed.

On the 6M intake plenium, it will say "3000" on the top of it, where the 5M will say "EFI". Also the 6M plenium will not have a EGR system/hookups on the plenium. Works great if you live in a area where you don't have emissions testing, or underhood inspections.

Finally (if you can find one of these puppies), the 6M ECU has a more aggressive fuel map programmed in it, thus you can retain the 182cc injectors. The 5M ECU does not have the different fuel map, thus the reason why we tell everyone to upgrade to the 210cc 4AGE injectors.

[Supra Bob]

Thanks guys... was just wondering if maybe the Cams had changed a little mostly... Trying to find a cheaper alternative to having a set of 5M cams welded up and reground.

And before anyone suggests it... no, I don't wanna use Gude's. I have yet to hear someone say a good word about them.

[SilverMk2]

Cams are the same as later 5M parts (84+). I'm not sure what the difference is between 82-83 and 84+ cams other than the early ones had 5 dowel pin holes vs 3 on the later parts.

[Digilog]

I can remember from reading a web page on 5m/6m Specs that the intake runners on the 6M are slightly larger than than that of the 5M.

Digilog

[SilverMk2]

6M intakes are the same size as all the performance pack 5Ms. The lower manifold is identical and the upper is the same except for the lack of an EGR flange and it say "3000" instead of EFI.

[MK2Racer]

So if you were to buy a 6m block with pistons and crank, what else could you not reuse from 5m? From the sounds, the intake will work, but say EFI instead of 3000, but so long as it works, who cares what it says? More directly, what (owning a 5m now) is the least would I absolutely have to buy or modify to change to a 6m?

[BillyM]

Everything running off the v-belts would need to be replaced, as the 6m has the 84-86 serpentine, alternator, (waterpump and tensioner should come with).

Hypothetically speaking, all you should need is the bottom-end and an alternator.

--BillyM (also wondered what the MINIMUM stuff to purchase was)

[SupraDOHC]

Would it be possible to just replace a 5M crankshaft with one from a 6M? The difference in cranks is what gives the 6M .2 more liters of displacement right?

[Supraa_luva]

I just realized that my engine still has the EFI on it. Does that mean the shop that installed the 6m-ge reused the original for the EGR hookups since we're in cali?... is that possible? For an instant there I'm wondering if they put in a 5m and said they put in a 6m. Am I being paranoid?

[edit]nm on the 6m ecu. just read another post on that.

although what would be in the approximate increase in hp in installing the 210cc injectors? and is that something a novice can do alone?

[MK2Racer]

Different..
...
upper manifold (& lower for 82-83 + 84 auto cars)
...


I have an 82 5m, when I switch to the 6m I CANNOT re use my exhaust? I ask because I just bought new exhaust today under the assumption it was the same as the 5m. I was told somewhere that just about everything non-internal-engine was a direct swap.


-Ken

[jr85mk2]

Ken,
The reference was to the intake not the exhaust. You will be fine.




Different..
...
upper manifold (& lower for 82-83 + 84 auto cars)
...


I have an 82 5m, when I switch to the 6m I CANNOT re use my exhaust? I ask because I just bought new exhaust today under the assumption it was the same as the 5m. I was told somewhere that just about everything non-internal-engine was a direct swap.


-Ken

[CJSREDPRA]

Supraa_luva

Your "paranoidness" is valid.

If you're not "positively sure that you had a 6M installed, then you'll need to look at the engine ID stamping. Best way to look at is, is from underneath the car.

1. Remove the engine undercover thingy, or at least remove the majority of the bolts on the right side.

2. With a flashlight, look around for the engine stamping marking. It will be in the right side of the motor & it will be to the right of the oil filter mounting flange. It will either say "5M" or "6M" on it.

It SHOULD look like this: (this is from Phil Dupler's webpage, when he was rebuilding/doing the turbo conversion on his 6M).

http://www.celicasupra.com/dupler/silver.htm

From the top of the webpage, go about 1/3rd of the way down. OR... Count 23 pictures.... You'll soon see the picture w/ the engine marking on it.

And yes, since you are in Cali, it's more than likely they reused the 5M intake plenium, so that the EGR hookups can be reused, so that you can pass emmissions inspecions.

[MK2Racer]

Thanks, had me worried for a minute there.... :)


-Ken

[Supraa_luva]

whew.... thanks CJSREDPRA. I checked and it's a 6m. lol.

[CELICA XX]

My brother and I went to look at this Black 85 yesterday. The owner came out and begins to explain to me it has a "Japanese import motor." I am instantly thinking 6M, he lifts the hood and I see the normal EFI on the intake. I have read about the 6M stamp on the block, but I cant see it unless I actually get under the car (pictured below).

After searching the forum, it appears that many of the differences [6M vs. 5M] are within the engine itself.
Finally, here is my question: I am looking for additional external visual differences for the 6M-GE.

Thanks!

1985 - Automatic Transmission - 99% Rust free - $1950
http://img.photobucket.com/albums/v490/celica_supra/Forum/1095072795.jpg

[CJSREDPRA]

Off the top of my head.....

6M marking next to the oil filter.

3000 marking on intake plenium (if being used).

No EGR system (see above).

Slight differences on pulley/fan belt arrangement. Forgot what they were exactly, Jamie Bergen (ghostrider) can elaborate.

That's pretty much about it. Others????

[StanS]

Does anyone have a dyno run(s) with afr for a 6mg with minor or no breathing mods run with a 5mg ecu?

[SilverMk2]

The only real way to see if its a 6M is to look for the block stamping. You can see it from the top, but its usually covered in oil. The 3000 intake with no EGR is a good sign, but most people I'd say install the 5M intake back on.