M20B29 w/ Triple Webers into my '71 2002

[stanhayward]

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

[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....
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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.

[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.

[ForcedFirebird]

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

[LJ851]

Very nice, Andrew !

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

[CorvallisBMW]

Holy shit, beautiful!

[MR 325]

Looking good Andrew! 8)

[mr2peak]

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

[DER E30]

\
Once the bits were back from powdercoating I mocked up the new setup …

That's gonna look amazing !

[SkiFree]

I don’t have much free time again, so this’ll be kind of jumbled together. Cylinder head rebuild is finally done! Working on another piston option that should be kind of neat (hint: involves Mahle Motorsport)!

Cylinder head rebuild (strangely this was spread out over a year-ish)

Goals: In line with everything else, going for a fun hot-rod 91octane street engine. The idea was to port-match the exhaust ports while cleaning up both the intake and exhaust bowels.

New parts list
-IE 284/272 dual-pattern new cam
-IE HD Rockers
-oem dual valve springs
-valve guides
-IE SS Intake Valves
-IE SS Exhaust Valves
-OEM Rocker Shafts
-Elring Upper Gasket Set
-rocker hardware+eccentrics
-OEM Oil sprayer bar
-OEM Spring retainers (top and bottom)
-OEM valve cover studs (with M30 acorn nuts) Intake Studs (with thin IE 11mm nuts)
-Allen-head exhaust studs w/ copper nuts
-Freeze plugs

Tools:
Die Grinders
6”mandrell
carbide bits
80 grit cartridge rolls
120 grit cartridge rolls
rubber hammer
Bearing, Seal, and Race Drivers Kit
wrenches/sockets

First thing was sending the head to the machinist to have the guides punched out, head checked for cracks and warping, and lastly cleaned!

Port matching the exhaust side

Pretty straight forward. Painted the port with some trusty dykem lay-out fluid, 2)lined up a head gasket and scribed the ID with an exacto knife.







Started with a pretty beefy carbide bit, as long as I kept it lubed it made short work of the aluminum.



Next I wanted to clean up the intake and exhaust bowels. Mainly the casting ridges you can see here and the small edge immediately inside the short side of the port (you can feel it pretty easily when hooking your finger in there.

You can see how this was MUCH easier with the guide removed.

Casting ridges


First pass with the carbide bit



Stepped it up to 80 grit cartridge rolls on the end of a 6” Mandrel

Ended up with a 120 grit and went ahead and polished the combustion chambers for good measure.



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Next step was sending the head back to the machinist with new guides and valves. The machinist then did a nice 3-angle valve job, punched in the new guides, and resurfaced the head.



Before dropping off at the machinist.



After picking the head up from the machinist.





From this point it was all basic reassembly work.

Valve Stem seals went back in using the little sleeves supplied in the upper gasket set to keep the valve edges from cutting into the seal. Using the OEM stem-seal tool was kind of neat, didn’t know it existed..




On to the new springs, retainers and collets. Broke out the spring compressor. Compressed spring/retainer right before slipping the collets in.









Cam’s turn.



Rockers and rocker shafts were next. I could slide all of one bank on pretty quick. Pushing in the second shaft however meant that I was going to reach a point where the cam would need to be rotated for the rocker to go on.




Made up a handy head stand from some aluminum around the shop (in hindsight I should have moved the dowels farther forward).




Kind of neat but the M20’s rocker shafts are interchangeable from intake to exhaust while those found in the M10 and M30 are not. Rotated the shafts and snapped the rocker retainer clips in place.



Last major step, studs, oil sprayer bar, freeze plugs, cam seal/o-ring.

When installing the seals and or freezeplugs...
1) On the OD of the seal, run a thin layer of good gasket sealer (I like Dirko).
2) On the ID of the seal, run a smear of good synthetic wheel bearing grease.



Already to go!





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After thinking long and hard about it I made the call to switch to throttle bodies instead of carbs. My dcoe manifold wasn’t panning out and the more measurements I took the more I realized that carbs just wouldn’t work without compromising somewhere.

Went ahead and picked up a Racehead 40mm ITB setup.



With the ITB’s in hand I wanted to at least replicate the look of an old Alpina setup (red stacks, grey valve cover). Sent the parts of to Nick at Rodini up in Fremont for powdercoating.

Once the bits were back from powdercoating I mocked up the new setup ….

[deutschman]

Good stuff Andrew. Cant wait to see and maybe hear more ;)

[kid325e]

Love it. The cutouts in the spokes are pretty cool!

[SkiFree]

Can't resist a nice wood steering wheel, this one's out of Sweden; a period Personal Autostrada (oem option on a couple Italian clunkers).

[SkiFree]

Dang it! I've got some really good news coming in about two weeks (no, car's not running but some major steps forward finally)!

Rear axles are done, will post more on that this coming week.

Side note, Jeff's number 5 car is out from hibernation to be worked on this winter. Working on a drysump M10 with 336 hollow cam. Should give the 510's a run for their money. Will try to start a fresh thread for that car.

[TrentW]

Oh yes, we're all in need of some news Andrew.