Water Pump Diff's - EA82 Carbie vs. MPFI

L-BJ · Post by **L-BJ** » Thu Jul 03, 2008 10:54 pm

Simply put, are there any differences between the Carbie and MPFI water pumps? I know the EA82Turbo ones are different and the MPFI's have more in common w/ the Turbo's than carbies, so me thinks the MPFI & turbo one's would be the same???

And approx how much would i be looking at for the MPFI water pump (plus gasket and rings etc) if they are diff to the carbie ones.

Subafury · Post by **Subafury** » Thu Jul 03, 2008 11:20 pm

from what i remember the MPFI and turbo ones are the same and sticks out 10mm further (closer to the rad) than the carby one. for some reason my turbo motor had a carby one on it when i replaced it, go figure.
you're looking at about $100 for any of em.

YouTube · Post by **El_Freddo** » Fri Jul 04, 2008 12:24 am

No difference between the carbie and MPFI water pumps.

There is a difference in the "height" when the pump is sitting on the bench - This is for engines fitted with the flat belt as opposed to the pretty common V belt setup.

This is where the differences occur with the MPFI Turbos - those that run the flat belt or those that commonly run the V belt.

Price, the $100 sounds pretty steep - I don't remember paying that much for mine, but then again, I'm in Victoria and not WA...

Cheers

Bennie

steptoe · Post by **steptoe** » Fri Jul 04, 2008 9:59 am

El Freddo is correct from my same experience. I ordered a turbo pump 115mm deck height ? only to find i had to set its deck height to 110mm in the press because I run the V belts not the flat ribbed belts for air and alternator

paid 10 bucks more for the privilege

Subafury · Post by **Subafury** » Fri Jul 04, 2008 8:26 pm

ah ok my bad. i can only go from my experience and just thought like most things efi and turbo are the same.

discopotato03 · Post by **discopotato03** » Sat Jul 05, 2008 3:09 pm

I think there is some variation in the pump impellers as well . The pump that came out of my turbo XT4 Spider engine was not the same as the one that will replace it . The original one had a slightly smaller cast impeller with more blades than the the newin , my rally people prefer a larger impeller with less blades because they say its a better all rounder and lets face it water pumps have to operate over a wide speed range .
I don't recall the brand of the new pump but its one the engine builder has had good results from . He did say it was specified as non turbo but I reckon that had more to do with the pulley mount flange height .

As for EA82's , I look at them as carby or EFI and turbo is a variant of the EFI family . I get the feeling that the EFI versions were a little beefed up for higher torque outputs along with the better heads/manifold/breather system .

I was originally going to go with the poly V belt accessory drive but after the airconn went over the shoulder (sure the front end lifted !) the usual V belt is much simpler and readily available . Need an EA82 carby alternator bracket which fits an EFI engine with power steering pump .
Importantly if you convert an engine to spider manifold try to get the XT's crank pulley timing pointer bracket and make a top dead center mark on the V belt crank pulley . RX ones are harmonic damper V belt type crank pulleys .

A .

A .

steptoe · Post by **steptoe** » Sun Jul 06, 2008 10:56 am

Is that because the spider blocks the timing hole at the fly ?

discopotato03 · Post by **discopotato03** » Sun Jul 06, 2008 6:53 pm

Yes I believe the hole in the bellhousing ends up under the throttlebody or its duct so hard to see the marks .

Cheers A .

Gannon · Post by **Gannon** » Sun Jul 06, 2008 7:53 pm

Put simply

Carby, SPFI. MPFI and Turbo motors with V belts have a common waterpump.

MPFI and Turbo motors with Serpentine/ Flat ribbed belts have a similar waterpump but the pulley spigot is mounted at a different height.

Carby, SPFI. MPFI and Turbo motors with the normal intake that lays close to the block have the timing marks on the flywheel.

MPFI and Turbo motors with the Spider Intake have the timing marks on the crank pulley (technically not a harmonic balancer cos Subaru's dont need them) and there is a small plate bolted to the waterpump to show the timing marks against

L-BJ · Post by **L-BJ** » Sun Jul 06, 2008 8:49 pm

Cheers everyone, will be of much help tmrw.

discopotato03 · Post by **discopotato03** » Mon Jul 07, 2008 10:10 am

Ahh yes they do actually . You only get one power stroke at a time not two so they don't actually cancell each other out .
A four cylinder flat plane crankshaft has 180 degree phasing in both inline and flat four configurations . Also a really strong block is a one piece iron one not a split aluminium cased one .

Any engine that revs (EA81/82 single carb forget it) will have a critical vibration in usually the upper range and if the engine speed is held in this area usually the crankshaft dies a horrific death .

If the crank pulley has a rubber sandwich type construction it IS a harmonic balancer because its their to absorb harmonic vibration .

A .

YouTube · Post by **El_Freddo** » Mon Jul 07, 2008 2:58 pm

discopotato03 wrote:If the crank pulley has a rubber sandwich type construction it IS a harmonic balancer because its their to absorb harmonic vibration .

I'm with Suparoo - Subaru's don't have a harmonic balancer. Ever had your front pulley off your engine Disco? Its all steel, no rubber except the belt once you put it on...

Bennie

Xtreme_RX · Post by **Xtreme_RX** » Mon Jul 07, 2008 5:11 pm

discopotato03 wrote: If the crank pulley has a rubber sandwich type construction it IS a harmonic balancer because its their to absorb harmonic vibration .

He is right. Some models of the 'L' series had a rubber sandwich type 'isolator' in the front crank pulley. I have 2 or 3 of them here.....

YouTube · Post by **El_Freddo** » Mon Jul 07, 2008 10:12 pm

Xtreme_RX wrote:He is right. Some models of the 'L' series had a rubber sandwich type 'isolator' in the front crank pulley. I have 2 or 3 of them here.....

No sh!t? I've NEVER seen one! Got a pic?

Bennie

Gannon · Post by **Gannon** » Tue Jul 08, 2008 4:51 pm

Me too

I have an EA81, an EA82 carby, an EA82 MPFI and a jap EA82T and none of them have a harmonic balancer

discopotato03 · Post by **discopotato03** » Wed Jul 09, 2008 3:24 pm

Well mine is supposed to be an 85 build 86 registerd car here in Australia . Probably lived most of its life in Mexico (LOL) and migrated to spud city for a big 2nd wind ...

At times with other cars I have seen manufacturers do a few little extras like this on early versons of a model and delete them over time if they thought it was unnecessary - read could cut costs .

In my case I'd rather have it than not because with some of the restrictions removed I want this thing to rev easily to ~ 6G .

Cheers A .