Nice and clean!Quote:
Originally Posted by Ralph
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Nice and clean!Quote:
Originally Posted by Ralph
Visited the hallow grounds of Ed Pinks today to make some power runs on their chassis dyno. Touring that place was like a kid at Disneyland - incredible history there. I saw many motors being assembled, from motors for Singer, Emory Motorsports and even a 917 flat 12 for Seinfeld. Crazy. Sad part is LA is forcing them to move so they can demolish their building to build bus stops for the Olympics. Glad I got to go to the original shop before they relocate.
Now the fun part. My 2.5 put out a very surprising and impressive 250hp and 232tq at the crank (accounting for 15% drivetrain loss); 217hp and 201tq at the wheels. Torque curve is exactly what I wanted when I chose my cams and the HP comes on much lower than a peaky cam would - yes, I lost some peak HP with these cams, but didn't want to rev high to get torque and HP out of the motor - this thing is really drivable through the streets and freeways here in SoCal. Still can't believe these numbers out of a 2.5 liter that doesn't have modS or more aggressive cams in it (I went with Mod Solex). With my car weighing 2,133lbs, this is a power to weight ratio of 11.7, or 10.2 if measuring power at the wheels. Not bad for a mild and very drivable hotrod with only 2.5 liters. MFI is pretty well dialed in - curves were mostly smooth.
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Wow, that's a lot of torque for a 2.5L. Do you have a build thread somewhere?
Thanks - yes, the torque is exactly what i was looking for when i built my motor. here is my build thread - warning, it is very long!
https://rennlist.com/forums/911-foru...rod-build.html
Here are the specs to my motor:
- 2.54 MFI Longstroke
- 9.5:1 compression
- Single plug, stock ignition
- 87.5 slip-in LN Nickies cylinders (this gets me to 2.54 liters with no boring needed)
- JE pistons
- Dougherty Racing DC30 Cams (which is a mod Solex cam - see below for specs). Many discussions with John Dougherty to arrive at this decision based on where I want my power range.
- Intake and exhaust bored to S/RS specs (36i/35e)
- Heads were ported and polished by Ollies
- Case was done by Ollies - oil by pass mod, inserts, align bore, etc
- Throttle bodies by Matt Blast, stacks by Aaron Burnham (bored to S/RS specs)
- Modified MFI Pump to match motor specs by Mark Jung
- Stock rods, but they were balanced along with the crank, flywheel, pressure plate, etc by Ollies
- ARP rod bolts and flywheel bolts
- Mahle Clevite Calico rod bearings
- Oil pump is Glenn Yee Motorsports GT SERIES 1 port and polish
- SSI heat exchangers and Dansk sport muffler (dual center out)
I was hoping for something in the 190-200hp range with a broad, usable power range - and finally, I wanted it to be reliable and very drivable. So far, this is how things have shaken out - but with more power and torque than i expected :)
Being a long stroke improves torque, as well as the increased compression ratio, and I was careful not to over cam the motor -- based on where i expected to spend most of my time in the RPM range. this is not a race motor where i would be at high RPMs and speeds regularly. so for this reason it does run out of breath after 6k RPM - but everything below this is strong, usable power. This is another reason I was ok using stock rods (rebuilt and balanced though) - this is not meant to be a screamer motor.
The data for peak torque and HP were approximations based on my research - however, the dyno showed different results for my car.
Attachment 589610
Nice, I'm surprised there's no crazy race engine stuff going on. My (supposed) 2.7RS spec is getting a bit long in the tooth. It's got a murky history, definitely with some abuse in the past. Current diagnosis is a worn MFI space cam (groove worn into the part of the fuel map I cruise in) so it's looking like it's time to consider building an engine in a couple years. I'm surprised you can get so much torque from a 2.5 liter (more than the 911/83 specs) without resorting to anything crazy. I'm considering what to build- 2.2S, 2.5SS, 2.7RS, etc. I think I'll likely go with some sort of EFI or M-EFI, and figured I would twin plug it while I was in there. I like my 911/01 gearbox though so in the name of preserving it's longevity I'm thinking of targeting a smaller but hotter engine that will give me similar torque but better fuel economy (with the EFI at least) and be "rowdier" when I want.
Drove her for the longest most spirited drive of the season. Good news - no issues and the high Idle when hot has disappeared. She ran like a Top.
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Used my new laser to make an NLA gasket for my steering rack. Then made some anodized and etched aluminum labels for my custom fuse setup.
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New tires for my ‘65 today on the driver wheels.
John
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I got 28 mpg at 80 to 90 mph Rennsport to Golden, Colorado with a 2.4 POLO (4) and EFI. And now I'm going from 42# (440cc's) injectors to 28.7 (310cc's) injectors. At sea level maybe 30 or 36#ers might be better. I had to back off the fuel in high load and ran too rich under 1/4 throttle. I think I'll get better low load drivability and maybe mileage. Maybe 30 mpg cross country. EFI is nice. I can be on Vail Pass with my phone plugged into my laptop, my laptop into the ECU and a software person tuning it from anywhere in the world. I do the minor stuff myself. I'll install the injectors this weekend.Quote:
Originally Posted by Flieger
After 2 days of on/off fitting , wiring Attachment 605460and struggles with headlight trim fit against body seal…
My Cibies are on !
Now for the other side …