Project Heavy Metal - an all steel classic, remastered

[jjeffries]

Jonny....this is SO COOL! Love the analysis, test rig....I may have previously revealed myself as something of a SPICA man....so this is just the bee's knees. Bravo. Have you ever read Jan Norbye's book on Fuel Injection? Kind wishes, John/CT.

[Jonny042]

Originally Posted by jjeffries

Jonny....this is SO COOL! Love the analysis, test rig....I may have previously revealed myself as something of a SPICA man....so this is just the bee's knees. Bravo. Have you ever read Jan Norbye's book on Fuel Injection? Kind wishes, John/CT.

Not sure if I have.... but it looks familiar. Way back then I was probably skipping over the parts about MFI and going straight to the EFI stuff! I remember when the first conversions of sidedraft webers to EFI throttle bodies started happening, exciting stuff for a young car fanatic. I couldn't even come close to affording any of it but I could buy books and magazines!

Which is why I always have to laugh when people ask me - "wow, how do you know how to do all this stuff?" I tell them I've but studying and practicing my whole life!!!

[BURN-BROS]

Originally Posted by Jonny042

Hi Aaron,

Thanks for checking in, I appreciate it.

I priced one of those "overflow valves" as Porsche calls them. At $161.00, I'm glad mine is working well! My backup plan was to hide a modern regulator under the car.

It's a spicy meatball for sure!

Originally Posted by Jonny042

This post by Early S Man describes the restrictor. Basically a 1mm orifice in the location I showed in my etch-a-sketch schematic markup.

Interesting, why only 73my(and I assume all the euro mfi)?

Originally Posted by Jonny042

Honestly, it's an honor to have you checking in on this thread! I know you put together that GORGEOUS MFI powerplant for STR 002 and it has been a big inspiration to me. I keep watching the Jay Leno video and hope I can get mine to run half as well! Any tips on tuning the MFI pump? I've got datalogging for throttle position, MFI rack position, AFR, and RPM planned. And I have a good idea what the WOT/full rpm fuel delivery should be.

Well thank you very much Johnny! It was a fun build and was an relatively easy tune. I am sure you will do brilliantly.

Originally Posted by Jonny042

I'm using the 2.7RS space cam, DC43-102 (Kinda like Mod S+) 39mm/36 ports and waiting on the new 41mm SSI heat exchangers. Might temporarily use ebay 1-5/8 headers if there's a wait on SSIs.

I'll give you anecdote about a 3.2SS build I did. MODS cams 10.5/1 twinplug, Euro ports. Client ran 1.625 headers and some sort of sport muffler. The car was nice but was underwhelming in performance. The power curve was done right around 6000 rpm. The client wanted to step up to the DC60(which I love). I told him if we were to go that route I wanted the Dansk/RSR setup with George's 1.625 headers. I suggested we install these prior to a cam change as I wanted to see how it would run...It turned into a proper beast. power to 7500 after a adjustment to tune for the reduced back pressure. The client was so satisfied that he no longer required the bigger cam. It's an absolute blast to drive! So I have found that once you start getting to the bigger displacement engine, it's almost all exhaust choice that will dictate the character of the engine.

Originally Posted by Jonny042

Last but not least I'll be installing a classic retrofit CDI+ so I can program the curve I want.

Thanks again!

I haven't done this yet, But its on my to do list. interested to see how it goes.

[Jonny042]

Originally Posted by BURN-BROS

It's a spicy meatball for sure!




Interesting, why only 73my(and I assume all the euro mfi)?





Well thank you very much Johnny! It was a fun build and was an relatively easy tune. I am sure you will do brilliantly.




I'll give you anecdote about a 3.2SS build I did. MODS cams 10.5/1 twinplug, Euro ports. Client ran 1.625 headers and some sort of sport muffler. The car was nice but was underwhelming in performance. The power curve was done right around 6000 rpm. The client wanted to step up to the DC60(which I love). I told him if we were to go that route I wanted the Dansk/RSR setup with George's 1.625 headers. I suggested we install these prior to a cam change as I wanted to see how it would run...It turned into a proper beast. power to 7500 after a adjustment to tune for the reduced back pressure. The client was so satisfied that he no longer required the bigger cam. It's an absolute blast to drive! So I have found that once you start getting to the bigger displacement engine, it's almost all exhaust choice that will dictate the character of the engine.




I haven't done this yet, But its on my to do list. interested to see how it goes.

Hey Aaron,

I'm not clear on why the restrictor only on 73 but read somewhere that perhaps it has to do with the relocation of the pump to the rear in 73? Regardless, it would seem it's a valid option (adding a restrictor) if it was felt a bit more pressure was required. From what I can see you don't actually need more than slightly positive pressure at the pump head to keep fuel flow to spec, the MFI pump is a positive flow device after all. Of course if you retained the cold start solenoid you'd want to make sure you have healthy pressure.

I might try tapping the tank inlet banjo to accept a carb fuel jet and see what affect it has - once I have the entire system in the car to verify pressure/flow. I think I have some mikuni jets on hand that go down to 1.15mm.

One question about the exhaust changes on your clients motor - did the headers change in any meaningful way (both 1-5/8" OD, or ID?) or would you attribute the exhaust flow increase to the Dansk RSR muffler entirely?

It's always struck me that pushing 275-300 hp through exhausts made for 2.4L motors is going to be a struggle. Dansk coming out with the 41mm (OD) SSI's should be a help.

Lastly, do you know if that 3.2SS that you describe used a 2.4L pump with a 2.7RS space cam? I know Magnus's STR used a 2.0"S" pump which I've read works ok when calibrated for a larger motor.

[Jonny042]

I added a final few tools to my MFI setup arsenal - this little gem is required to set the internal angle on one of the levers inside the pump. It took me far too long to make:



I also had to make an adjustable fixture for setting the pump cold start enrichment to full warm, for testing.



I had previously made a few other tools, a puller for dismantling the front of the pump and a delivery valve extractor.





There are a grand total of FOUR digital readouts on my test rig, all of which are necessary to perform the pump tests. Including a DTI on the rack (with homemade adapter) and a handheld tach.





Last night I finished setting up the internals of the governor/compensator and perfomed the first few tests and adjustments. This seems to be going really well - precise, and repeatable. The rack travel baselines are set prior to doing the real meat of the tests, the volumetric measurements.

At some point I am going to have to figure out how and where to make the necessary adjustments for the greater fuel requirements - this will be a WAG for now, but I plan to map out the effect of the various adjustments on fuel flow so I can have a better chance of dialing in a curve that fits the requirements of the motor. There is more than one way to add (or subtract) fuel. Adding fuel at the main rack should be linear across the speed/load range but I need to verify this, and also map out the effect of various changes - IE I know that adding fuel to the midrange with the governor would have the same effect as reducing fuel at the low and high ranges and then adding with the main rack. However there would be a difference, and depending on the motors needs, one approach might be better that the other for a given case. Knowing this ahead of time (with a particular focus on effects on the light throttle delivery) should help to get the AFR dialled in sooner.

I should probably be taking notes.

[GaryR]

Originally Posted by Jonny042

I should probably be taking notes.

This should be the Pelican Tech Forum 2019 winning phrase!

[Jonny042]

Originally Posted by GaryR

This should be the Pelican Tech Forum 2019 winning phrase!

Haha! Yes. I'm going to dust off an old laptop to keep at the shop so I can enter all this in a spreadsheet, at least.

I realized this threads sex appeal has dropped way down...... this should help, courtesy of Aaron Burnham: I had it saved in my "MFI Stuff" folder.

[BURN-BROS]

Originally Posted by Jonny042

Hey Aaron,

One question about the exhaust changes on your clients motor - did the headers change in any meaningful way (both 1-5/8" OD, or ID?) or would you attribute the exhaust flow increase to the Dansk RSR muffler entirely? .

Header size did not change, They were equal length, but just set up for the production muffler convention. The inlets on the RSR muffler are very large.

Originally Posted by Jonny042

It's always struck me that pushing 275-300 hp through exhausts made for 2.4L motors is going to be a struggle. Dansk coming out with the 41mm (OD) SSI's should be a help.

The inlets on the stock muffler are the beginning of problem. That system was based around the 2 liter and works well to about 2.7 depending of rpm range.


I typically run the stock air cleaner housing, but I do not install a air filter. If some one makes a free flowing foam filter for the stock air filter housing, then I would probably utilize it. I have not bothered to search. There is restriction in the air filter element and I think some have reported a pretty significant HP loss when installed.

Originally Posted by Jonny042

Lastly, do you know if that 3.2SS that you describe used a 2.4L pump with a 2.7RS space cam? I know Magnus's STR used a 2.0"S" pump which I've read works ok when calibrated for a larger motor.

IIRC It was a 2.4T . I usually choose this as I can machine the stock space cam to suit my needs....Also, 2.4T cams are cheap since everyone steps up to the RS cam. the pumps are also relatively common and are the lowest cost to obtain.

If I run an early pump, I have a Mercedes space cam installed simply because they are easily replaced and cheap.

I think the HP limit of any of the pumps is about 450hp. So I wouldn't chase a specific pump. If you were boosting then I think you may need to be selective, like a 69 pump but I am guessing.

[BURN-BROS]

On the STR build 9 and all the big displacement builds), I modified the throttle bodies and stacks.
Specs are..
38mm intake
41mm throttle plate
46mm stack tapered down to match the 41mm throttle plate.


On the more competition based builds I use 2.2 MFI stacks and Throttle bodies as I can get much larger.
42mm intake
44 throttle plate
52mm to 44mm on the stack and run PMO 50 Air horns.

I have also stopped using the steel fuel lines and have gone to plastic. The heat from the heads are heating the lines up all the way to the injection pump and the modern fuel is not formulated to take the heat. The cars a dealing with vapor lock during high ambient temps and short stops like filling up for fuel. The plastic lines help with this tremendously.

[Jonny042]

Originally Posted by BURN-BROS

On the STR build 9 and all the big displacement builds), I modified the throttle bodies and stacks.
Specs are..
38mm intake
41mm throttle plate
46mm stack tapered down to match the 41mm throttle plate.


On the more competition based builds I use 2.2 MFI stacks and Throttle bodies as I can get much larger.
42mm intake
44 throttle plate
52mm to 44mm on the stack and run PMO 50 Air horns.

I have also stopped using the steel fuel lines and have gone to plastic. The heat from the heads are heating the lines up all the way to the injection pump and the modern fuel is not formulated to take the heat. The cars a dealing with vapor lock during high ambient temps and short stops like filling up for fuel. The plastic lines help with this tremendously.

Lots of good info, Aaron, thanks! I machined to 41mm on the plates - I THINK there's room to go to 42mm but haven't worked up the nerve to try . My stacks at 45 top/39 bottom.

Something tells me I am going to be exhaust restricted... might have to re-think my plans.

[Jonny042]

Tonight I tested my injectors, since I figure calibrating a pump around bad injectors probably isn't wise.

Out of the 6 "professionally cleaned and tested" injectors, none of them were good. I have one new one on hand to compare them to, and really there is no comparison. The new one lets out a series of "chirps" as it lets of pressure, the old ones just dribble and squirt all over the place and wont hold pressure.

5 more new ones on the way! In the meantime I am going to try to clean these ones up but there's a chance they are just "done".

An action sequence.... not much to look at, sorry.





Also since I've decided to do my own heads, I dug out my Neway seat cutters but I was right in thinking they'd be a bit small for the 911 valves.

[Jonny042]

Well the fedex truck from Australia showed up at my door this morning..... the plan for these is to try them out in my autox car first then perform the same swap (with adjustments if required) into the SC trans for use behind the MFI 3.2. This new 2.00 2nd and 1.381 3rd will give me the same 1/2/3 ratios as the mythical SC/RS trans with a slightly taller 4th and 5th. Co-incidentally, it's not that far off the 2.7RS gearing.



The peakier motor will like shorter gears and by all accounts will make either car a lot more fun to drive. In particular the autox car spends 95% of it's time (when competing) in 2nd gear. Driving around on the street I find I have no use for a 3rd gear that will take me to 100mph!!!

The gear chart is really interesting to look at and compare. The 3rd to 4th upshift in these cars is wicked - keeps you right in the meat of the powerband and feels like a million bucks. But of course how often do you make that shift at or near redline? Practically never. If you do, you must have different law enforcement than I'm used to.

So my gearing steals a whole bunch of that fun and gives it to the 1/2 and 2/3 shift which lets face it, you use a heck of a lot more often. Can't wait to try it!

[Jonny042]

See if I can make that easier to read:

[Jonny042]

It starts to come into focus a bit when you compare my new gearing to the 2.7RS chart.

My new gearing has a lot more in common with the 2.7RS - however the higher first is a bonus and the longer 4th and 5th are (I think) a good compromise, but I'll consider stepping up to purchasing a new 4th for Project Heavy Metal if I think it will improve the driving experience.

[Jonny042]

So I've been selling off some parts in an effort to tidy up the shop a bit. Hard to keep motivated in the dead of winter. One morning last week is was -37, without the windchill!

I did however, get started on cleaning up the case. This is the result of a couple of hours work. Mostly scrubbing, solvents, brushes, and elbow grease. I'm trying to recreate the look of a freshly cast block, although I can't help but perform a bit more deburring and smoothing that they did at the factory. Imagining what it would be like if they had spent more than a few minutes dressing the castings by hand at the factory. Removing flash, sharp edges, etc.



A long way to go, and I need to remind myself 90% of what I am doing won't be visible once it's together. But a clean case is the foundation that all else is built on!

[GaryR]

I did a glass beading (after removing squirters) followed by a solvent flush.

[Jonny042]

Originally Posted by GaryR

I did a glass beading (after removing squirters) followed by a solvent flush.

Looks good, Gary! I do lots of glass beading but this block doesn't warrant it, it's coming up nice and clean without resorting to such drastic measures.

Of course the heads, cylinders, chain cases, etc. will all get bead blasted but they are a lot easier to clean/flush.

[Jonny042]

Well I finally got a complete set of injectors and tested them, which didn't quite go the way I thought it would.



A few of them took almost 400psi to "pop" the first time, and several also did not have a fine mist spray pattern, but more of a forked spray.... It took a few really good flushes with the tester to get them chirping and spraying the way they should. They are all perfect now, holding pressure the way they should instead of dribbling etc.

Of course I mounted them in the test stand and hooked the 6 lines up and plugged the power supply in, and "ZAP!!" there was quite a spark as I plugged in the ebay special 12V regulated power supply...... and nothing. I guess that $12.99 bet didn't pay off but you can't win them all.

New power supply should be here in a week or so.

[GaryR]

Originally Posted by Jonny042

Looks good, Gary! I do lots of glass beading but this block doesn't warrant it, it's coming up nice and clean without resorting to such drastic measures.

Of course the heads, cylinders, chain cases, etc. will all get bead blasted but they are a lot easier to clean/flush.

Thanks Jonny, the chain boxes and valve covers were all given a couple coats of Eastwood satin clear (fuel resistant) and really held up quite well.

[Jonny042]

I know I said I didn't want to turn this into and engine build thread, but do have a few things to share.

NEW TOOLS!!! Neway seat cutters and pilot. Also a bunch of other supplies for doing the guides.





Also, sent back the GT3 conrod bearings since there seem to be issues with them. Well, not only them, but the ones in the motor since the last rebuild! They are about 2.5mm narrower than they should be. More info:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/1017939-rod-bearing-alignment-edges-off.html