"Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by gav p »

Whilst the engine was out, I took the opportunity to get the heater boxes restored by Alan. Along with new cables, hopefully the system will be more reliable than it used to be -

Image

However, more excitingly than that, a very busy weekend was had in the garage installing the engine in the car, and setting up the new underwing oil cooler. This all went relatively smoothly, to the point where the car was ready for first start on Monday. Since my garage is surrounded by neighbours at close quarters, I decided to get Nick to trailer the car up to Redtek for the start and initial run up. Once everything was double checked, we cranked it over, and it fired pretty quickly :)

Image

A great moment after all the hard work.

Once things had started to warm up, a little reality check appeared in the form of an oil slick at the front of the car... it turned out that during my full-on weekend bolting things together I had forgotten to torque up one of the oil cooler unions under the front wing. This was tightened and then we moved on.

After some initial fettling, it was off down the road to roadtest for basic MFI setup. Nick managed to get the main rack set pretty quickly to give correct performance at mid and high end, but it proved impossible to lean out the idle rack sufficiently. However, in general the engine feels very strong even at part throttle to 4500rpm :)

The next stage will be a trip to the rolling road to get some proper readings for setting the MFI pump accurately - after running it in for 1500 miles during the scotland trip of course :P
Gavin

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'94 968 Sport
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by sladey »

Great stuff - fantastic for you to hear it start for the first time - no video?
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by Lightweight_911 »

Excellent progress Gavin !
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by gav p »

No vid I'm afraid - not that organised! It did sound fantastic though, probably something that the iphone would struggle to do justice to...
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by willbrown »

admiring your progress gav - brilliant effort. hope the first run in during the scotland weekend is as fun as it sounds. sad not to be there, but looking forward to seeing the new beast soon 8) 8)
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by Bootsy »

Great stuff Gav - see you in Scotland!
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by gav p »

Thanks gents :o)

The running in is now well under way - we drove up to north yorkshire for the weekend, and then yesterday came up to Loch Tay for family hols the week preceeding the Highland Tour. Engine ran like clockwork and is starting to feel strong. Will be interesting to see what its like above 4500rpm in due course....

The only minor teething problem is a small oil leak from where the rubber oiltank hose meets the oil cooler - this occasionally drips oil into the heat exchanger which then burns up and comes out of the passenger side air vent, something which Emily found a bit concerning when it first happened.

This is being caused by the somewhat gnarley state of the oil cooler outlet. May need some sort of sealant between the rubber pipe and the alloy . Thinking maybe loctite 574 or some joint sealer, although would need to drain the oil to do this. Can wait till first service i think....

Anyway, the highland lodges are lovely as before - great to be back! Looking fwd to seeing more ddk cars dotted around the lochside on friday :o)
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by Bootsy »

Good to hear the forward party has arrived and doing a reccy. See you on Friday Gav
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by hot66 »

You should have given us a shout if you were in n.yorks :)

See you Friday hopefully :)
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by gav p »

Finally got a minute free to post an update...

Scotland seems a long time ago now, but was a great running-in trip for the new engine. Firstly, it was completely reliable, which I was very thankful of given that a few friends on the trip were not so lucky. The only anoying teething problem was a slight oil leak from the oil cooler hose, which dripped onto the right hand SSI once very half an hour or so when hot, and sent oil smoke through the heating system and into the passenger-side air vents. Not something Emily was particularly impressed with :|

Apart from that, the only other incident was when Grandma took a lift in the back of the car whilst staying at the Loch Tay lodges, and managed to set off the fire extinguisher whilst getting in! I am still finding powder in the cabin 4 months later...

Anyway, the car really felt quick around the highlands. I knew it was running rich though, and this was confirmed by the horrendous fuel consumption for the entire 1700 mile trip - 17.8mpg including 1000 miles of 70mph motorway cruising. Still, the strong performance on the DDK trips around the highlands more than made up for that, especially the trip to Applecross and back, which had some unforgettable moments.

So, after Scotland it was time to take a trip back to Brackley and get the car on the rollers. An initial run up, giving 194bhp, was followed by some tweaks to the timing and the mixture, and a further 5 runs.

Image

The sound was fantastic - really an assault on the senses. I will try to post a video or two next, although the iphone does not really do it justice.

Anyway, the final run had the mixture leaned out a bit more, the timing advance nudged slightly more, and we ended up with final figures of 214bhp @ 6250rpm and 205lbs torque @4650rpm. Really happy with these figures, which I feel are testament to the potential of the E cams - good BHP and mega useable torque at mid RPMs - just what I was after. Very pleased with that :)

Image
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by gav p »

However, having got the performance I was after, it became clear that there were still some issues to sort out. In particular, having leaned out the mixture in order to get the top end performance, the low end/around town performance really suffered. Basically it became a bit of a pig to drive around town - leaning out the mixture had really shown up some fueling issues at the bottom end. These characteristics are just like the issues the old 2.4 engine suffered from

So since the dyno run, i've gradually been ticking off potential causes - focussing on the one key component shared with the old engine: my MFI pump. And thus began my journey in becoming an armchair "expert" on Bosch MFI pumps...
Gavin

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'94 968 Sport
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by impmad2000 »

excellent numbers there Gav, and the graph looks pretty flat too. I certainly remember the run back from Applecross !! I'm sure it will keep giving as it loosens up with use. Enjoy :) !
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by gav p »

OK here's one of the initial dyno runs - turn the sound up 8)

https://www.youtube.com/watch?v=IgK0Ud8 ... fccZeAWBhw

- looking a bit rich....

And here is the final power run, complete with fresh air feed from Nick. Much cleaner this time:

http://www.youtube.com/watch?v=NdD47SRKy1Y&sns=em
Last edited by gav p on Tue Dec 16, 2014 10:16 am, edited 1 time in total.
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Re:

Post by gav p »

impmad2000 wrote:I certainly remember the run back from Applecross !!
Yep, that was the drive of the year, as far as I'm concerned Tim :wink:
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Re: "Sleeper" hotrod - homebuild 2.7CIS to high comp 2.7 MFI

Post by gav p »

Second dyno video clip added above :)
Gavin

'73 911E -> 2.7mfi
'94 968 Sport
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