My low cost high compression daily driver E85

[knochgoon24]

I'm part of a club at my college that is building a high mileage vehicle starting with a 5 hp briggs and stratton block. When it's all said and done, we're going to be running 16:1 CR on iso-octane (100 octane), but we only need the motor to last 4 hours of on and off testing.

Good luck with 13:1 boosted with E85! I hope it works for you.

 

[mobythevan]

I'll measure cranking psi with stock 2.0 turbo cams when it is together this weekend and then we can try to figure a more realistic compression ratio, given that I am at 6400 feet altitude so cranking psi is already ~18% lower than sea level. If the cylinder pressure is too high for what I want then I just throw in bigger cams. Its an easier problem to deal with than having low compression.

 

[mobythevan]

I got the engine and tranny pulled over the weekend. The clutch was in worse shape than I expected so I put a new clutch kit on order. Other than that everything is going smooth, should have it back together as soon as the clutch comes in. It was a good time to pull out the original 2.0, the rod bearings were worn pretty good and the clutch disc/PP/TO bearing were worn to the end.

 

[Black_Bullet]

Im interested in knowing the results! 13:1 shouldnt be a problem with e85, moderate boost levels and lowish timing. Your MBT will be found at a lower timing advance number so you wont need to run aggressive timing maps. Should make for a fun car when finished.

 

[hpexperts]

sick build!!!!!

 

[mobythevan]

thanks, but remember this is just a quick and dirty junkyard build to experiment with the higher compression.

 

[mobythevan]

Well, my TO bearing did not make it in this weekend, so in my spare time I decided I should check the piston to valve clearance. After all, that is what I started this thread for, to see if anyone had run various cams with the 4g63 head on the SOHC flat top pistons. I just don't like the idea of the clay method and not really knowing when the valve events occur so I grabbed the hack saw and made my own checking device.

Here is step #1, it took a while but seeing inside must be worth it

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Here it is with the stock turbo cams installed and only 1 intake and 1 exhaust on number 4 where I will be looking

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A view of the chamber show the 2 valves are fully in tact for measurements.

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Here is the final result with already squished head gasket.

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This is what happens when my parts run late. A little JB weld should put it back together.

 

[hpexperts]

nice!!

 

[tenn-gsx]

I really hope that was a ruined head already.

 

[mobythevan]

I really hope that was a ruined head already.

Why, are heads hard to come by?

 

[gixrman]

Now will the stock starter be able to turn over a HC motor?

 

[tenn-gsx]

Not really but I hate to see good parts destroyed. Eventually heads will be harder to get.

 

[mobythevan]

The car is together and running. I let it warm up and then checked compression. 225psi at 6400 feet altitude. My 2.0 was 130psi at altitude. I believe I am 18% lower on the numbers being this high, so at sea level the 2.4 would show about 270psi cranking. My best guess would say it is right around 12:1 compression. I am going to drive it for a week or two with the wastegate loose to see how everything does.

 

[dsm-onster]

Great. Keep us updated on the potential of corn.

 

[mobythevan]

Well I put about 200 miles on it over the weekend. The first 150 miles with the wastegate open so it built no boost. Everything seems good, I had to retune a bit for the extra displacement. I pulled timing across the table to be conservative. I also richened the fuel a bit to start with. Today I connected the wastegate and ran it with the factory 9psi boost. I gave it a good 5 second 4th gear pull, seems smooth. I don't notice any detonation, but I don't have a knock sensor so I am listening only. My exhaust is quite though. I have heard light detonation with pump gas. I think next weekend I will use a det can to listen better. It certainly has more torque off the turbo, but no way to know how much without a dyno. The high compression is a little weird to get use to, it kind of reminds me of a motorcycle engine now. It revs pretty fast and slows down quickly. It starts instantly and when you turn the key off it dies fast. Just different. Sometimes the starter will catch it on compression and it almost stalls the starter, but usually it cranks up fine. Pretty interesting experiment, we'll see how long it lasts before the HG or pistons go.

 

[hpexperts]

keep us posted, adn good work.

 

[Black_Bullet]

Well I put about 200 miles on it over the weekend. The first 150 miles with the wastegate open so it built no boost. Everything seems good, I had to retune a bit for the extra displacement. I pulled timing across the table to be conservative. I also richened the fuel a bit to start with. Today I connected the wastegate and ran it with the factory 9psi boost. I gave it a good 5 second 4th gear pull, seems smooth. I don't notice any detonation, but I don't have a knock sensor so I am listening only. My exhaust is quite though. I have heard light detonation with pump gas. I think next weekend I will use a det can to listen better. It certainly has more torque off the turbo, but no way to know how much without a dyno. The high compression is a little weird to get use to, it kind of reminds me of a motorcycle engine now. It revs pretty fast and slows down quickly. It starts instantly and when you turn the key off it dies fast. Just different. Sometimes the starter will catch it on compression and it almost stalls the starter, but usually it cranks up fine. Pretty interesting experiment, we'll see how long it lasts before the HG or pistons go.

What are you tuning with and why not use a knock sensor?

 

[mobythevan]

Megasquirt, so no knock sensor. Supposedly you can use a knock sensor with it but I never heard of anyone having success with that. Scary huh? It is almost unheard of for people with DSMs to not use a knock sensor to tune with, but it is what it is.

 

[JWoodley]

Think you could grab us some video action? Seems like a sweet buildup.

 

[turboglenn]

Megasquirt, so no knock sensor. Supposedly you can use a knock sensor with it but I never heard of anyone having success with that. Scary huh? It is almost unheard of for people with DSMs to not use a knock sensor to tune with, but it is what it is.

I tuned my car and many others for years with no knock sensor (hondas, scubyies, DSM's etc...) it's all about being thoughtfull adn paying close attention to the engine behaviour and sound. Then when you start to push the envelope you can read plugs on the street, or you can even see detonation as puffs of intermittant black smoke on the dyno. (looks different than running rich)

 

[sniver]

Not to often you see someone do something different around here. I'm eager to see what happens with this. Nice work.

 

[mobythevan]

I drive it 60 miles a day to work. So far so good. I can get going from a dead stop so much quicker now without having to rev the engine. Just take off like a typical non turbo car and then boost hits quickly as well. As this point I am a little worried about how long it will last, but I am not going easy on it just because of that(got to have fun). I got on it several times yesterday and verified that the stock 2.0 turbo cams are too small for the larger displacement. I expected that, but didn't come across a set of cams yet. They flatten out pretty good above 4500rpm. Atleast I think it the cams causing that. I want to go with 272 cams to keep it nice for the daily commute. Otherwise I think 280's would be real nice for street/strip. I think its really going to open up with 272 cams so that is my next priority. As it sets right now, I bet I can surprise a few people at the stoplight. When they don't hear any rev, then instant rpm and gone across the intersection

There are some pretty long hills on my commute home and with the old 2.0 setup the car would pull between 3-5psi boost to maintain the speed limit of 65mph. Now I am a little less than zero on the boost gauge to maintain the speed limit on the same hills. So I am not even getting the engine to full throttle much less any boost. Like I said before, we knew the 2.4 was going to pick up torque and then add in the compression bump on top. I am happy with it.

 

[hpexperts]

post a video of it, i want to hear it and see it running

 

[mobythevan]

I'll try to shoot some video this weekend, just need a second person to get some good driving footage.

 

[mobythevan]

I am at 500 miles on the setup now. The new CFDF clutch should be broken in well. When the car ran on pump gas with 2.0 I would get 27mpg. When I switched the 2.0 to e85 I had to increase fuel by 34% which put my mileage at 18mpg. With the 2.4 engine now I am getting 22mpg. I am only down 18% on mileage with e85 so that starts making the e85 actually cheaper than premium versus the old setup and being down 34% on mileage. The e85 around here right now is 25% cheaper than premium. So I'm finally saving a little bit by running it and getting the extra benefit