BC

Nope, good discussion. I had to drill down a but to understand the charge cooling definition in reality, as I was initially confusing it with the cooling that will happen in the port from spraying the ethanol - even up further than the injector. It is an open deck block, so with the peak pressures, there can be NO detonation or PI. NONE. If there is, it will probably balloon the tower pretty quickly.

I am going to build this lump with extra parts I have had in boxes for too long, and the block is actually a repaired unit that had the classic "Alternator console" rip off from some bump or curb long ago. The 12.5 CR is from an earlier version of the 32V pistons and a later version of the 32V heads. Everyone says it can't even turn over with that combination and I showed through testing it myself it can. So now I want to run it, first with no boost to see how the engine fairs with the cams, and then go for broke.

I believe that warranting the peak pressure issues and sheer mechanical force, it will be a very strong engine. If it blows up, I have a more normal Late/Late long block combination with just a 10:1 CR. The other part of the puzzle for this high CR is the cams that bring down the dynamic compression to a more sane level technically. But I may try a set that have a wider LSA.

I'd like to apologize to the OP as this is off topic relatively completely now.

I personally feel through all my research and applied tests that the e85 is a wonder-juice combination with higher CR and a certain level of boost.


JUST wanted to add this article as well. A bit less clear on its full facts, but good: http://www.ethanol.org/pdf/contentmg...ine_Blends.pdf

Dave W.

Another point worth highlighting from the MIT thesis is that E85 only knocked when timing was advanced beyond MBT. See figure 3.1. located approx 1/3 down the page. E10 with PFI knocked right at MBT, E20 with PFI knocked slightly beyond MBT.

Another trend that's commonly seen in the DSM/EVO world is that when using higher compression ratio there's a fine line between being on the good side of MBT and being beyond it. For example, when doing timing sweeps while tuning on the dyno, adding one degree of timing might give 12 HP, then adding another degree might give another 12HP, then adding another degree adds nothing. Whereas a low comp engine will show a gradual reduction in HP gained per degree of timing. For example, adding one degree of timing gives 10HP, adding another degree adds 8 HP, and the next degree of timing only yields 5HP. It's a broader safety margin.

I found a nice thread that shows a real world example of the limits of octane, timing, boost and compression ratio. http://www.e90post.com/forums/showth...t=world+record
I like this example because there's datalogs posted in the thread. The car was using 109 octane race gas with approx 1200cc of meth injection(110+ octane), boost was 25- 26psi, and the engine is direct injection with 10.2 comp ratio. The meth was injected with 4 nozzles, two in the intercooler inlet, two in the IC outlet. The datalogs show timing is lowest at peak torque, approx 6 degrees at 4500rpm, and timing peaks at 13-14 degrees at 7000 rpm. If the comp ratio of this engine were raised higher, all else being equal the only way to keep it from knocking is to pull timing, and timing is already very low. If it was port injected instead of direct injection the timing or boost would have to be lower to keep it from knocking. Take this example with a grain of salt since the BMW engine has a few key differences such as a bore/stroke ratio that allows a slightly faster burning combustion chamber than the typical Porsche.

Dave W.

"certain level of boost"? I know you said you have a pulley rated for 28psi, so this is a supercharger? Can you begin tuning at lower boost, such as 5 psi?

BC

Yes, of course. It will be technically a sort of handicapped lower boost package. You can throttle the SC intake ports, and you can also use a waste gate on the intake side. These are not permanent solutions of course, but the 28psi is a pulley ratio and airflow calculation for a NOVI 2000. I believe that with the intake tract changes it will be lower PSI as there should be less restrictions. Also this setup was used with an engine with stock exhaust manifold.

I wish I could ramp it up like a turbo, of course, but that's not for this project.

V2Rocket

restrictor plate, BC?

BC

Sort of. Tim Murphy was experimenting with a plate type control over the SC intake.

MooreBoost

isn't there a thread for e85???????

https://rennlist.com/forums/944-turb...ga-thread.html

blown 944

progress is moving along now.

Shortblock is in the car. I decided to go ahead and install it to fab up some other items.
I have my AOS replacement pretty much done. Using a Moroso AOS can and a lot of fittings. This is not an inexpensive venture. In hindsight, I should have just gotten ahold of Dave at CEP. All total I think I have around $340 into it. However, It should look pretty nice when done.

I also got my head back from having the final work done to it. It has 47mm intake valves now that are back cut. The throats are cut to 90% and the whole runner area is apprx the cross sectional fromintake flange to seat.

I am also adding some stronger inner valve springs to be prepared for a higher lift cam down the road. I had to machine the inner mating area of the spring cups to accept a slightly smaller ID spring. I also machined the retainers in the same area. Stock was .704 and I machined them down to .692. This allowed me to choose a much more aggressive spring. The cool thing is that I can buythese springs for around 60 bucks through JEGS. (they are for a SBC). This combo will allow me to go up to a .540 lift cam if I choose.

I have also been finalizing the huge oil cooler under the IC. It is all plumbed up and mounted now.

I have also been doing some final fitting of teh intake I got from Bruce (95ONE). I have been polishing it and match porting it.

Here are a few photos from my phone













Certainly not as nice as some other builds on here, but I'm trying to make it a littel better while staying low budget.

refresh951

Spring is right around the corner! Nice!

333pg333

Great to see this build back and moving Sid. Some interesting things happening there. Clearly quite a different intake than the one Shawn is proposing. Certainly won't have to worry too much about the T-body to plenum tube when calculating the overall plenum volume as compared to Shawn's. Just looking at the angle of that tube makes me wonder about flow to the cylinders though?

blown 944

It seemed to work fine on bruces setup at higher boost. We will put it on the glow bench soon.

It has 220mm runners (not including head). It also has a 4liter plenum volume from the tb flange to the mating flange of tge bell mouths. The plan is to set up this intake since it needs more fab work, then swap to the stock one with the BMW tb at the dyno.

I'll be running this engine I just like the last one. Which will be around 12 psi (wg spring pressure). With the 2.85, that resulted in apps 350rwhp (track). I expect this one will do a tad better. I'd like to see 400 rwhp at 12 psi. If I can attain 130 mph at less than 20 psi, I'll be happy.

333pg333

Hope so and that's great that you're doing some back to back tests.

400whp at 12psi!! That's numbers I just don't correlate. Good luck with that.

Pauerman

Project looks great Sid! I am very interested in hearing how your oil cooler performs. I remember Richard L. mentioning that he saw higher coolant temps with a similar radiator / oil cooler combo configuration in standing traffic.

For your smaller ID inner spring mod, the "lip" on the lower cup is only .028" thick. Do you think the machined .016" lip is going to be strong / thick enough to hold the spring?

blown 944

Hey, nice to see you posting. Thanks.

I've ran this intercooler for quite awhile now. The oil cooler is mostly below the radiator. What I did was slant the radiator bac at the top to allow some airflow between the ic and radiator. It worked great on the other engine. This one is not filled (just deck plated). So more coolant.

I am also going to use an electric pump to feed coolant into the back of the head. I have a fitting made that is in place of the freeze plug now so I can just pull the plug and install a -12 90* fitting.

gruhsy

Fantastic work