My low cost high compression daily driver E85

[dsm-onster]

Get some logs up when/if you can. I'd like to see 70-90mph times and airflow numbers. Also after you get it tuned are you going to take it to the track?

 

[mobythevan]

This is a megasquirt car so no airflow numbers I'm afraid. I had no plan to take it to the track since overall it is a slow daily driver, but I would like to get it on the local dyno and compare to my friends talon who has the indentical setup to my old 2.0 setup. We should be able to compare the two and see what torque gains were made throughout the curve from the 2.4 and compression upgrade. Before changing my engine our setups matched in every respect, same exhaust sytems, mufflers, FMIC, turbo porting, cams etc. As close as two cars can be. We also both ran 18psi boost. His car is heading to paint jail this week, so we won't be able to hit a dyno until it is back. It will likely be a month before his car is back.

 

[toofast82]

That would be great to see side by side dyno comparisions of the two setups
Glad to hear everything is working out

 

[mobythevan]

I talked to my friend about getting both cars on the dyno after his paint job, he also wants to do this. Hopefully in a month we will have results. I checked compression again at his house his and it showed 220psi on all four with his gauge at 6000 feet. Did not get any video, sorry, but I did make time to see Watchmen. I loved it, the smartest guy on earth, heh heh.

 

[Empyrials]

i just found this thread and it's awesome!

great job man, really looking forward to the dyno #'s

 

[mobythevan]

Anyone thinking about running this same combo should read the following link and remember that I am running dedicated E85 at high altitude.

KB Performance Pistons-Bench Racing

 

[toofast82]

Good read, thanks for the info

 

[myturbo]

this looks awsome..my only problem is that it wont hit the rpm ammount like a 2.0 and i love rpm

 

[mobythevan]

I set my dual boost switch for 14psi last night and tried it out. 14 pounds feels really good, pulls better than 18psi did with the old 2.0. That gives me 9psi on the low setting for typical driving and 14psi when the need arises.

 

[biglady112]

I am way excited. This is the kind of stuff I like to see. I am glad it is working out for you. I hope she stays together. That is a HUGE jump in the compression numnbers. Far more than I thought it would be. Sick man.

Steven

 

[jking29]

What kind of timing are you running up top?

 

[turbotalon1g]

Nice, You don't happen to be on hybridz too. do you?
I had to read this twice, this is awesome.

Good luck, please keep us updated and get on the dyno asap!!

Now i have another reason to come to colorado. (i want to go to CO to see all the sweet rides and i like driving)

 

[coltboostin]

So, is it 100% confirmed that he is using a stock G4CS with a DOHC head?

TO me, THATS a big deal.
__________________

 

[mobythevan]

Unless there are other engine blocks stamped with G4CS and my 1990 Talon TSI came with a different head than a 4G63, I am positive that is what I have, but anyone is welcome to visually inspect and verify. I don't have a problem with that. The pistons are the G4CS SOHC types. The compression measures 220psi at 6000 feet altitude. By my math the compression would measure ~270psi at sea level. I would not try this engine build at sea level unless you use larger cams to bleed some compression off.

I took the car to Cripple Creek for some gambling over the weekend. It did good but it did get some light detonation climbing the hills at part throttle. I notice the fuel map is too lean in that area, so I fixed it. I did have a scare when I came out to the parking garage the next morning and noticed a big oil spot under the car, but my oil is full and the spot didn't look fresh so it must have been someone else. I need to check parking places better before I park next time.

Nice, You don't happen to be on hybridz too. do you?

I'm on hybridz and several other sites with the same login. I have seen some of your posts over there.

What kind of timing are you running up top?

I'll have to look on my laptop to see, I don't remember off hand. I pulled a lot of timing with this build from my old 2.0 spark table.

 

[dsm-onster]

I don't see why this is so hard to believe. ??? It's always been common knowledge that it's knock that kills sirius pistons, not cyliner pressures. We all know what e85 can do. The benefits of e85 are not for engines that are built for pump gas. For example, it starts to dwindle the fuel mileage difference once we realize how much compression can be run regardless of boost and still see good results without detonation. Taking advantage of such high thermal efficiencies is what the major manufacturers are doing wiht direct injection so that we can still be reliant on fossil fuel. But, in the OP's case, no expensive direct injection fuel injectors with special mounting locations after the intake valve, and no super high pressure pump is required to boost at a high n/a compression ratio.

 

[mobythevan]

From the thread in the newbie area it came to my attention to point out that you need an 8 valve 2.4 block with the 4g63 head to arrive at this compression. The G4CS I used was 8 valve. If you use a 4G64 then it needs to be 8 valve, so truck, van , etc.

That will give you this piston which is basically a flat top with 2 valve reliefs:

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[hpexperts]

nice build keep us posted

 

[mobythevan]

The car is still running good. Still waiting on my friend to get his car back from paint. I've put around 3k miles on it now and I love the low end performance for daily driving.

 

[dsm-onster]

This thread has inspired me to run my 2.4 in my n/t car. I've been doing so much research and then just came back and measured my piston dishes for my 2.4 4g64. It is 15cc DISH. Swapping a 1g or 2g 47cc head onto this block will not alter the compression that the motor originally had from the factory: 9.5:1 (per the 2.4L FSM).

The DOHC 2.4 motor has a head identical to the 2g head. Head volume and all.

Here is a pic of the 4g64 DOHC piston beside an n/a 4g63 piston:

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Look how healthy that 4g64 "SA" dish is. No need to worry about valve to piston contact since the n/a 4g63 piston has so much less dish. The valve reliefs of the n/a 4g63 piston are much shallower than the dish of the 4g64 "SA" piston.

So again to verify. IF you have a 9.5:1 CR (from the factory) 4g64 that had the DOHC head, then you can swap dsm heads all day long and your CR will be 9.5:1 not +11:1.

Here's a CR calculator for reference.

 

[mobythevan]

Thanks for updating. I only ended up with the higher compression by using the 2.4 SOHC pistons. BTW, my engine is still running good at 14psi boost. I still love the way it drives and the off idle response it has.

 

[dsm-onster]

I'll bet! 12:1 compression with 2.4L displacement. Must be fun anywhere in the rpm range!

 

[chanley talon]

I have been reading this thread and i have a couple questions? First what years did the 4g64 come with a dual overhead cam? Is this a 6 bolt or 7 bolt motor the dual over head cam version? Next, can the sohc motor except the dual overhead cam pistons? Third is 9.to 5 to1 hard to control on a stock eprom with a modified timing maps for higher compressions? I am also curious what you think about running a cyclone intake on this as well a torque spooling monster.Just looking into possibly doing this bottom end swap to gain more power in my automatic awd.

 

[mobythevan]

Thought I would throw another update. Car is still running good, I'm starting to get bored with the ~300hp level. I think I want to get some lower compression forged pistons in the engine now and a new turbo with a high pressure ration so I can get up in the 30psi area at my altitude of 6000+ feet. I think my friend is ready to move his Talon up in hp as well. Maybe we can both start tearing our cars apart

 

[needsy]

Did you ever run it on the dyno? I'm curious to see the power band.

 

[mobythevan]

No, I never did. I'll try to keep my promise and dyno before I make any more changes.