4Age Fwd To Rwd

[omni86]

It's important to convert the water pump to Rwd. It very well may be your problem.

I did a lot of research when doing my conversion from a fwd 4age to rwd. Rwd is always running a higher pressure load on the engine by enough for the pump to make a difference.

 

By passing the heater core is common, I did the same.

Always good to double check the hose.

To work out air when doing the rad, cut the end off a 2litre and raise water level well above the radiator.

Also to work out air, 1 remove rad cap and put it back with out tightening it, to allow air pressure to build and bubble out.

Also a plastic bag with a few small holes rubber banded over the rad filler can work.

[ke70dave]

I did a lot of research when doing my conversion from a fwd 4age to rwd. Rwd is always running a higher pressure load on the engine by enough for the pump to make a difference.

 

Higher pressure load?

[omni86]

Someone mentioned while i was doing the conversion. That because of the rwd layout there is more resistance for one engine rotation and that is why fwd/rwd pumps have different bearing sizes/ribs. To cycle at different rates. I guess my question was why do they have different size pumps? Mixed answers and non descript in most fwd/rwd conversion post I read up on at the time.

[Sam_Q]

It's important to convert the water pump to Rwd. It very well may be your problem.

I did a lot of research when doing my conversion from a fwd 4age to rwd. Rwd is always running a higher pressure load on the engine by enough for the pump to make a difference.

 

By passing the heater core is common, I did the same.

 

HIgher pressure load? can you explain what you mean by this? The front wheel drive pumps may well be a better pump in terms of flow.

 

Also what makes you think rear wheel drive engines have more resistance in rotation? The extra bearing and ribs are to handle the forces exerted from the mechanical fan and clutch.

 

Bypassing the heater is a bad idea because it's then a radiator bypass. It should always be blocked not bypassed.

Edited May 26, 2013 by Sam_Q

[omni86]

pressure load inacurate terminology. fwd/rwd components that differ aside from space issue, differ for reasons. Like you said rwd pump ribs/bearings for rwd's fan/clutch. I was under the impression it also has to do with circulation. Bearings I also understand prevent failure over the 5.5-6k rev range on a rwd setup

and was reccomended not to use the fwd pump.

 

If the fwd pump is"better" for flow, I have not heard of it as a common rwd 4age "upgrade".

 

rwd pushes fwd pull. the displacement of power through driveline to rotate a r wheel one turn.

in contrast to a fwd which has a more direct output. The fx off the line is faster than my gts coupe both stock. the fx can't uphill or downhill corners as well but is quicker to repond at lower speeds than the rwd gts. the ae86 coupe and ae82 both have identical largeport tvis 4age's both 87's even. the range of displacement is very noticeable in the fwd/rwd setup. its a combined effect from gearing but the trans/axle and trans driveline to rear axle require different ranges of torque for one drive axle rotation.

 

Blocking is proper. I haven't had any issues from bypassing the heater core it is functional.

[Sam_Q]

Ah you mean more resistance in terms of the extra loading from the greater inefficiency of the rear wheel drive line compared to the front, so more losses and therefore more engine load to sustain same vehicle speed and acceleration. I understand what you mean now but I can't imagine it making much of a difference in terms of cooling.

 

The front wheel drive pumps have an extra impellow blade, I won't pretend to know if this has much of an effect hence my careful wording.

 

Blocking the heater line is a good idea, otherwise you have a pretty serious compromise on your cooling system.

 

All this said 4age engines just don't run very hot usually. I ran my 20v for many years without a fan and a Hyundai radiator.

[ke70dave]

But the engine itself doesnt care weather its in FWD or RWD. The differences that you might be feeling is the different drivetrain configurations.

 

The engine just spins in its own little world.

 

I think your over thinking it. if you arent using a clutch fan any pump will do.

[Alvarado.e09]

Sorry guys I have been busy with junk.

 

I replaced the water pump with a New FWD Fx Pump i also Found the water pipe running alone the side of the block and installed, I also Picked up a Drizzy from the junk yard out of an Fx16 and i got a 86 ECU out of an MR2. No Engine lights No overheating. I still have idle hunt so I'm not sure if its the timing because i having found a timing gun yet, or maybe a vac leak.

 

I think i might have some bad news, I popped the hood to look everthing over before going to work and i noticed oil on the exhaust manifold. Looks like cylinder 3, So maybe my head gasket is gone i have no idea.

[Alvarado.e09]

I forgot to mention piston slap :( thats what it has to be I'm going to pull the plugs today after work.

 

I'm not sure what i should do next? I have the GZE Block in the garage but i kinda wanted to play around with the 4ag first to learn the car before i Boost.

Do i need a engine rebuild maybe or is this fixable? I guess next is compression test. I'm lost.

[Alvarado.e09]

It's been a minuet sense my last post. Quick update I did a compression

test and it's very sad also the 4ag was over heating because the head gasket was gone.

 

So I decided to go with the GZE instead of fixing the 4ag.

I've got all the turbo parts I'll need to turbo the GZE.

 

I pulled the oil pan on the GZE to tap it for an oil drain.

I found lots of metal shavings so I took a look at the bearings and it didn't look good.

The connecting rods didn't have bearings at all and are damaged very badly.

Also looks like the crank is damaged.

 

So my question is can I use the Connecting rods and crank out of the 4ag 7 rib big port

In the GZE block? I've also got a 3 rib big port 4ag.

 

Thanks for all the help everyone.