Engine Prep ?'s

#1

Hi All,

I’ll be picking my donor motor up this weekend. It will be going in an '86 325e. It’s an '87 engine that I’ll freshen up with new seals/gaskets, timing belt, windage tray, safety wired or welded oil pump nut and waterpump.

From what I’ve gathered in my research, the '87 coolant routing takes one of the hoses under the alternator. If there’s a lot of engine rocking or motor mount failure, the alternator has been known to chafe through the coolant hose under it. Additionally an '87 radiator is about $100 more than an '88 up radiator.

With all that in mind I’ll be installing an '88 water pump and radiator in the car. What other such “gotchas” should I be aware of and plan for?

Thanks in advance.

KB

#2

KB -

Good luck with that project. I don’t think anyone will care (or even notice), but the rules prohibit mixing-and-matching engine components. I would hate for you to carry the same burden of shame that I do.:wink:

But, again, I doubt anyone would care about a water pump. Radiator is free so you can use whichever you want.

Steve D.

[quote]
9.3.2.1. Cars that do not have an original type engine, (e.g. the engine was not available in the model, chassis and year of the car), shall be classed based upon the vehicle for which
the engine was original.

9.3.2.3. Swapping or mixing of engine or driveline components between different engine types is not permitted, (e.g. mating the head from a M40 engine with the block from a M10).[/quote]

#3

You are probably aware that you will need an “i” wiring harness, DME, TPS, and crank sensor, possibly other - cold start, oil pressure. The '87 radiator hose has not been a problem for us - we have 2 of them.

Ed

#4

They are both M20 engines. I wonder if that rule would apply?

John

#5

Hi Steve,

I’m gonna give you the game show buzzer on Line 9.3.2.3. :slight_smile:

Line 9.3.2.3 does not permit swapping or mixing of engine or driveline components between different engine types. The 87-91 325i/is all have the same engine type, the M20B25.

BMW changed the water pump and radiator on the 1988 325i/is model due to the radiator hose being potentially rubbed by the alternator if the motor mounts went bad or excessive engine rocking was experienced. No further changes were made to the cooling system after the 1988 production year. So 1988 through 1991 325i/is cars all have the same cooling circuit. The 1987 325i/is is the odd man out.

Line 9.3.5.1.1 says any radiator can be used as long as it’s similar in size and location. I would argue that the use of a different year water pump would be in support of the radiator swap.

It wouldn’t hurt if a line was added under Cooling to permit “substitution of water pumps for same type motor”. This would erase the grey area currently present.

There’s no performance gain here. I just want to build as safe and robust a car as I can. This updated cooling configuration will be the same as any other '88-up car and will eliminate the possibility of dumping fluid on the track due to the coolant hose being rubbed.

KB

#6

edavidson wrote:

[quote]You are probably aware that you will need an “i” wiring harness, DME, TPS, and crank sensor, possibly other - cold start, oil pressure. The '87 radiator hose has not been a problem for us - we have 2 of them.

Ed[/quote]

Hi Ed,

Yeah, I’ll be getting the ECU, harness and complete engine plus a 3.73 LSD.

#7

I have an 87 and yea the hose is kind of close but it has never been a problem. I’ll probably zip tie it further out of the way just to be safe. I bought a new (not reman) Behr OEM replacement radiator a couple of months ago from a place in Southern Cal called Just Radiators (or something similar) off of ebay for $155 with free shipping. Good luck with your project!

#8

rrroadster wrote:

[quote]Hi Steve,

I’m gonna give you the game show buzzer on Line 9.3.2.3. :slight_smile:

Line 9.3.2.3 does not permit swapping or mixing of engine or driveline components between different engine types. The 87-91 325i/is all have the same engine type, the M20B25.
[/quote]

Good point.

Looks like you have a good handle on the rules. I’ll leave you alone now.:laugh:

Steve D.

#9

While I don’t give “official” rulings, due to the fact that I just manage the Rules with the help of the Regional Series Directors, I doubt anyone will protest you for the water pump swap. And even if they do, it will not be a performance enhancing mod so any results from that weekend will stand.

Plus, I like your logic and I think NASA would too.

And if NASA (they enforce the Rules) says you have to change it by the next race weekend, we Spec E30 Officials have options.

Carter

#10

Thanks for the input Carter.

KB