M20B29 w/ Triple Webers into my '71 2002

[SkiFree]

DER E30 and Matt. Thanks, I know this project is going super slow just looking forward to finishing the motor and start stripping the car down. Matt, the new guy is working out great, thanks again.

Very clean work. Are you planning on an MS setup?

Yes, Keith (whodwho) actually built me a box when I was putting together the wasted spark system. I popped it open the other day and he had put together an entire MS2 setup in there along with x3 bip373 coildrivers already in there! I'll be adding the diyautotune fuse box as well.

Very nice, Andrew !

I think it's time to update the thread title, though...

yeeeahhh.....you're probably right. Now if I can figure out how.

HA! You mentioned you might pull the plug on the carbs. Good choice.

You kind of tipped me over the edge on that.

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As a compromise, an opportunity came up for the shop to buy back a car IE apparently helped build 15 years ago. It ran the 2000 One Lap of America and was featured in Bimmer and Roundel that same year. It's a rough car (square to roundie conversion done after the rear end was crushed) but...



It has an M20 with a triple weber IDF setup that Jeremy put together many moons ago! I'm thinking some tall stacks through the hood with a 250testarossa-style hood scoop would be appropriately obnoxious.

[SkiFree]

Hi guys, I'm stuck on one part of this injection thing.....

Using the following info for the injector flow rate and fuel pressure formulas...
BSFC: .45
Projected flywheel hp: 230-240ish
Duty Rate: %80

A couple different calculators I came up with an average of 21lb/hr@43.5psi(3bar). Alright, no problem, now to find some....
-------------------------------

I then found the popular yellow-top Ford injectors were rated at 19lb/hr@39.15psi.(according to ford oem specs).

After converting
x=rated injector flow x (actual fuel pressure/rated fuel pressure)

x=39.15 x 1.11
x=21.1lb/hr @ 3bar

So am I correct in thinking that the ford "19lb/hr" injectors are actually pumping out 21.1lb/hr when subjected to the 3bar M20 injection system? If so, that sounds just about perfect.

[stanhayward]

Aren't S52 pink top injectors 21.5#? The Fords might be cheaper though.

[SkiFree]

Aren't S52 pink top injectors 21.5#? The Fords might be cheaper though.

See that's the other thing ... the S52 pink tops are 21.5lb/hr at 3.5bar, but when you run them at 3bar then they end up being 18.3lb/hr. At least if I'm doing this right.

[digger]

Hi guys, I'm stuck on one part of this injection thing.....

Using the following info for the injector flow rate and fuel pressure formulas...
BSFC: .45
Projected flywheel hp: 230-240ish
Duty Rate: %80

A couple different calculators I came up with an average of 21lb/hr@43.5psi(3bar). Alright, no problem, now to find some....
-------------------------------

I then found the popular yellow-top Ford injectors were rated at 19lb/hr@39.15psi.(according to ford oem specs).

After converting
x=rated injector flow x (actual fuel pressure/rated fuel pressure)

x=39.15 x 1.11
x=21.1lb/hr @ 3bar

So am I correct in thinking that the ford "19lb/hr" injectors are actually pumping out 21.1lb/hr when subjected to the 3bar M20 injection system? If so, that sounds just about perfect.

its a pressure squared thing so 11% more pressure only gives 5.3% more flow.

1.11 x the pressure gives 1.11^0.5 x the flow

double the pressure gives 41% more flow etc

[ForcedFirebird]

I have had no problems with the m50 injectors making over 200whp N/A. The white car has 19lb and did 181 at the wheels with ample room for more.

[downforce22]

these just popped up locally and they seemed prudent for this thread

https://cosprings.craigslist.org/pts/4843850885.html

Extremely rare (1 of 13 in the world) intake setup for M20 engine. Came with a Jagermeister M3 race car that had these removed and went turbo. It has 44IDF carbs with large venturis - this was on a high-revving M20 race engine. Would need smaller venturis for a street car.

[SkiFree]

Doug and John, thanks for the help on the injector bits

To finish the injectors out then .... (credit to Digger on this)
YELLOW-TOP Injectors #19.0 @ 39.1psi (mustang application) = 20.0 @ 3b (E30 application)
PINK-TOP Injectors #21.5 @ 50.8psi (E36M3 application) = 19.9 @ 3b (E30 application)

Downforce, I saw those. Pretty crazy timing. The seller also had them listed on r3v. The same fella showing the ex-korman widebody racer.

[The Dark Side of Will]

I have 8 Ford orange top 19# injectors in my Caddy Northstar with stock fuel pressure making 312 to the wheels. Six should have no problem at all making 225 or better.

It's actually very difficult to get accurate BSFC numbers... AND 80% is a conservative duty cycle. I've typically seen 85% used as a target.

[SkiFree]

^ Thanks for the confirmation on that.

BMW 2002 Rear Axle Rebuild

With the new production CV’s finally ready to go I broke down and rebuilt an old grimy set of axles for the 2002. Below I just covered the basics.

Parts
x4 New CV joints
x4 New Rein boot kits
Zinc-plated hardware ** reused the originals, had them plated. (caps, u-washers)

Tools
x1,000 Disposable Gloves
x1,000,000 shop towels
Exacto knife
Flathead screw driver
Philips screw driver
High-temp Paint
Rubber hammer
Circlip pliers

What I started with:



1) First step was slitting the boots, taking them off, and cleaning some of the grease off.

**If you want to get a rough estimate as to the condition of your existing axles prior to disassembly take an axle, put one end on the ground and place the palm of your hand on the other end. Pivot the top CV with your palm, if it feels chunky like a bag of marbles this is not a good sign.

2) Removed the back plates gently with a flathead screw drivers, do it slow or you’ll screw them up.

3) Clear off the grease around the retaining circlip and remove it. Once removed you will be able to separate the CV from the axle. Most (but not all) 2002 axles used a bell washer behind the CV (see Toby’s note http://www.bmw2002faq.com/topic/6156...t-washer-gone/). Contrary to what I saw mentioned elsewhere, this washer is NOT specifically sized to the axle/cv. If your axles have it, then reuse it. If not, then don’t use it.

At this point pull off the inner cap from the CV face, again take care to not damage it.

4) With everything disassembled I cleaned/plated/painted all the bits to be used on the reassembly. From the old axles this means the shaft, the cv caps, the bell washers, and the circlips.



After cleaning and plating, ready for reassembly.





5) Assembly order (with minimizing mess-making in mind).

a) Slip new boots/clamps loosely onto the shaft.

b) Pack the inner side of the CV with grease and tap on the inner cap completely (use a couple old bolts to help line up the holes).

c) Using a rubber hammer gently tap the CV onto the shaft (don’t forget the bell washer if it’s the side where it came off of).

d) Once the CV is fully seated, reinstall the circlip, pack the backside with grease and tap the rear cover back on.
*This maybe obvious but be sure there is no play between the splines of the CV and shaft. If you have play, then something is going on with your shaft and you shouldn’t use it.



e) Put a bit more grease around the inner cap and then slide the boot right over. Snug the boot clamps down (take care to not don’t over-tighten or block an axle nut hole with the clamp’s worm mechanism).

f) Repeat 4 more times!
**During assembly a good trick is to use a very thin smear of Dirko (or your preferred brand) gasket sealer on the sealing surfaces to prevent grease leaks (rear cap, front cap face, boot mating surfaces).

All ready to go .... in a bag ... in a box .... until I'm ready for them.

[bradnic]

nicely done
Thanks for the walkthru - they're gonna look great on the car!

[TimeMachinE30]

I love that kind of work. Thanks for the photos and walk through.

What caused you to rebuild?

[ThatOneEuroE30]

Man this makes me jelly. Good work man

[SkiFree]

I love that kind of work. Thanks for the photos and walk through.

What caused you to rebuild?

It was another thing on my long checklist.

Got a little sidetracked and built an SpecE30 M20 for a local guy... the last picture is from about midnight last night. It went out today for the first time.

[efficient]

Wow! Looks so clean.
Needs a new coolant bottle though lol