Aviation gas

[ForcedFirebird]

I wish I could run pump gas:curse:

What compression are you? I know we discussed your car before, but a Fellow Floridian has run a properly designed engine (not m20, though) at 12.6:1 on 89 pump gas with no KR. It really depends on the cam design and if the chamber was shaped.

[b*saint]

What about 100LOL?

[mrsleeve]

If you get caught buying 100LL (or other aviation grade fuel) and using it in your car, there are hefty fines to pay. IIRC it is ok for offroad use in ATV's and bikes, but I could be mistaken there. Just something else to think about, though not sure how someone would actually get caught unless they were actually dumb enough to pump it straight into their car at the airport.

Why is this??? Its the same if you have red Diesel or kero, or Home brew bio, in your diesel powered car or truck and are driving it on the streets.

YOU SHIRKED THE GOVT OUTTA ITS TAX MONEY, thats it, not the EPA regs, no nothing just you fucked the govt outta its 18.5 or 24.5 cents a gallon plus state taxes and sales taxe on each and every gallon.

Why do you think when you drive a diesel truck with farm plates or, have construction compony stickers on the door you get your tank dipped to see if you have any off road fuel in it. SO they can fine the shit outta you to recoupe their taxes dollars and then some.

Now lead works as a hedge against detonation, and was used to stabilize high octane fuels. This is why cars went to complete and total shit in the 70's when all the emissions bull shit happend and Cats became mandatory on everything. Compression ratios had to be lowered on ever single car, because of the required use of unleaded fuel, the reason was it kills CATS. Also you have to remember that with the switch to unleaded fuels the valve seats had to be hardened as well, as lead build up was used as a sealing agent back in the day. With the lower comp ratios and the lack of lead in fuel, the octane ratings had to come down. With the lower compression combustion temps are not as hot, thus you get lead build up on plugs faster.

If you have low comp engine/or no boost, (ie M20's or any other production engine of the last 40 years) High octane and Lead serves you no benefit unless you have it built for it such fuel.


Firebird: 12:1 compression on pump 89 NOT IN THIS FUCKING WORLD, You are full of shit unless you have pulled so much timing outta it that you are not making any power at all. You would run into a fuck load of detonation any where even close to optimal. The only what you are gonna get that thing to run for more than a short duration, is to add, octane, cut compression, or pull timing out.

Cam profile really would not have much to do with this, as the valves are closed when the comp ratio takes over and has any control over engine power. Unless its a very low rise, short duration on the intake side, to limit the air/fuel charge to a very small amount of each, and even then I dont see how it would make a shit. Chamber yeah I can see how that can have a limited effect when optimized to eliminate hot spots and maximize swirl and atomization. Still though 11+:1 compression ratios on pump gas is not a real feasibility, with out pulling a fuck load of timing. Yes there the OEM's are getting comp ratios back up around 10-10.5:1 on pump 87, but thats with lots of computer help and pulling timing when its needed, based on real time fuel quality detonation issues.

[M-technik-3]

I wish I could run pump gas:curse:

Where's yours come from a well?

100LL great for cat converters as well, not.

[ForcedFirebird]

Firebird: 12:1 compression on pump 89 NOT IN THIS FUCKING WORLD, You are full of shit unless you have pulled so much timing outta it that you are not making any power at all. You would run into a fuck load of detonation any where even close to optimal. The only what you are gonna get that thing to run for more than a short duration, is to add, octane, cut compression, or pull timing out.

Cam profile really would not have much to do with this, as the valves are closed when the comp ratio takes over and has any control over engine power. Unless its a very low rise, short duration on the intake side, to limit the air/fuel charge to a very small amount of each, and even then I dont see how it would make a shit. Chamber yeah I can see how that can have a limited effect when optimized to eliminate hot spots and maximize swirl and atomization. Still though 11+:1 compression ratios on pump gas is not a real feasibility, with out pulling a fuck load of timing. Yes there the OEM's are getting comp ratios back up around 10-10.5:1 on pump 87, but thats with lots of computer help and pulling timing when its needed, based on real time fuel quality detonation issues.

Not full of anything, but power. I have been building these engines for 3yrs now, several happy customers. They are generally running 27* max timing in PE mode, as much as 31* cruise lean mode.

Three examples of running engines in recent customers' cars.

Customer #1 (that I mentioned):

5cc valve relief piston dish volume
3.652" bore
3.307" stroke
32.4cc chambers
pistons are .010" proud of the block
gaskets are .060" thick with a 3.8" bore

12.6:1 static CR

Customer #2

11cc pistons dish volume
3.622" bore
3.307" stroke
32.4cc chambers
pistons are .010" in the hole
gaskets are .060" thick with a 3.8" bore

11.56:1 static CR

Customer #3

11cc piston dish volume
3.622" bore
3.307" stroke
36cc chambers (I opened them personally)
pistons are .010" in the hole
gaskets are .040" thick with a 3.75" bore

11.38:1 static CR

Call me a liar? Here's a video of one of my top ends (same cam as the others)...

http://www.youtube.com/watch?v=0JAO3_2ztNs

I have no reason to lie, specially about an engine I build NOT supported on this forum. These engines have made as much as 271whp with a displacement between 3.4l and 3.5l. When they are used in the Midget race cars, they have been brought up to 14:1 SCR (100+ octane in that case, tough) and made well over 300hp with ITB's and open headers.

Cam profile can have an effect on compression, maybe not in the static compression, but it greatly affects effective compression as well as cranking compression.

There is one gentleman in Tampa running a newer 3.9l in his Fiero, twin turbos on a 10.8:1SCR with no issues, and is planning on going even higher this time around (he upgrades long before the engines fail).

OH, and here's an article we discussed on our 60degreev6 forum using a BMW as an example as well as an inspiration, not only is it 11.3:1 compression, but it has 8.5psi of boost added...

http://www.da-motorsport.com/projeler/mz3/mz3_en.htm

http://60degreev6.com/forum/showthread.php/41499-Boost-and-High-compression-example?highlight=

EDIT: The latest versions of these engines are the ly7 and llt. The ly7 is 10.2:1scr and makes 255hp in the Cady CTS, and the ly7 is 11.4:1scr and makes over 300hp in the new Camaro with direct injection.

We have boosted the stock 9.6:1 compression in the 3400 (aluminum head 3.4) to as much as 20psi using FelPro gaskets and head studs - one of them is in a Corsica that I designed and built the turbo kit - we never got a full dyno since the FWD trans axle spilled it's guts at 350hp, mad e a mess of the dyno lol.

[Pinepig]

pssh, maybe in CA

Actually it's illegal everywhere in the US, the problem lies with the fact there is no federal road tax on that gas. Using it in your car on breaks a federal law not state/local ones.

[mrsleeve]

Well Firebird guy, I will have to take your word for it, It flys in the face of everything I have ever known about engine dynamics. Just seems you should be seeing a FUCK Load of engine killing detonation no matter what you do other than retard the timing by 1/2 a day.

I a very familiar with the 60* I really want to know how you are pulling these comp numbers + boost with out shattering cranks, as there is no forged crank available for them other than the 3.5l with the Eaton on it. Last one I built 2.8 punched to a 3.1 the crank evacuated the via the oil pan making its own escape hatch at about 17psi. My bro is in the last stages of a Monster of a Lq1 turbo build.

[ForcedFirebird]

Well Firebird guy, I will have to take your word for it, It flys in the face of everything I have ever known about engine dynamics. Just seems you should be seeing a FUCK Load of engine killing detonation no matter what you do other than retard the timing by 1/2 a day.

I a very familiar with the 60* I really want to know how you are pulling these comp numbers + boost with out shattering cranks, as there is no forged crank available for them other than the 3.5l with the Eaton on it. Last one I built 2.8 punched to a 3.1 the crank evacuated the via the oil pan making its own escape hatch at about 17psi. My bro is in the last stages of a Monster of a Lq1 turbo build.

Hmm, was it you mentioning you have an S10 a while back?

The nodular iron crank is extremely strong. It has proven to hold 475wtq in a twin turbo 3.2l with the 3400 heads (11 second Chevette) before bearing were spinning, and that was only due to the two center mains stretching, which, I don't think would happen using the latter 3x00 block with the cross-bolted oil pan/girdle. I have not run any of these high compression motors with boost, the Corsica (broken trans on the dyno) has 9.1:1 compression, but Mars has run really high boost on his 3400 (9.6:1) through a Rotrex and is in the 11's with his Z24 - Kenton has high boost on a JY RMT Cavi, also running 11's.

The 3500 non-vvt from the Malibu/G6 (made from 04-06) does in fact have a crank that is forged close and machined to tolerance. The mains are the same size as the earlier blocks, but the pins were enlarged from 1.99" to 2.249". Using the 3500 crank in an earlier block would only take either the pins being ground, or to use SBC rods with the small ends bushed to accept the smaller 660 wrist pins.

If you are familiar with the 60v6, I am surprised you haven't heard any of this stuff, as we have been building swap packages to swap iron to aluminum heads for some time now. I work closely with WOT-TECH, and if you look to the left of his main page, you will see my logo. We are the ones fabricating the near-equal length headers for the FWD's (in my avatar pic), we make the billet TB adapters for the 65mm 3.5 TB's, we do all the iron head porting and flat tappet cams. We also supply stuff like the OBD1.5-OBDI swap harnesses and ECM kits.

Unlike WOT-TECH, though, we also cater to the GM 3800 v6. Recently we were able to gain 38% port flow on the over-sized boat anchor, and made 10 S/C kits to use Powerdyne's on them, we came out with the first direct-fit stainless valves, and also design custom cams.

I will tell you after seeing how much gain could be had from my 2.7i, I can;t wait to start applying some of my past experience with the e30's. My car was a DD for 3yrs, and just recently started adding modifications.

-Cheers, John

[tjts1]

In case anyone is wondering, 100 octane leaded aviation gas works just fine in e30's. :)

Until your O2 sensor and cat get poisoned.

Actually it's illegal everywhere in the US, the problem lies with the fact there is no federal road tax on that gas. Using it in your car on breaks a federal law not state/local ones.

Yup. There is a hefty fine involved as well. You are not allowed to use leaded fuel in road vehicles anywhere in the country.

[mrsleeve]

Yup. There is a hefty fine involved as well. You are not allowed to use leaded fuel in road vehicles anywhere in the country.

Unless its off road or built before 75IIRC

Yeah you get the shit fined outta you for running Off Road diesel on the street. It varies but can be 1000 fine plus up too 300+ per gallon of fuel found in your tank.

[uofom3]

Some useless, government mandated piece of shit that hangs under my car. We don't have emissions tests where I live, so I think i'll be taking it off pretty soon.

When I lived where there wasn't smog testing I took the CAT off asap - do it!

[M42Power]

We have 100 octane fuel at the gas station here

[rThor432]

Still though 11+:1 compression ratios on pump gas is not a real feasibility, with out pulling a fuck load of timing.

My S54 begs to differ. :)

[b*saint]

This makes me wonder where i can buy non roadtax gas for my gasoline generator and lawn mower.


HOLY SHIT IM AN E30 MASTERMIND NOW.

[mrsleeve]

This makes me wonder where i can buy non roadtax gas for my gasoline generator and lawn mower.


HOLY SHIT IM AN E30 MASTERMIND NOW.

Keep your receipts for all the gas/fuel you buy for your off road/power equipment, you then can write off the taxes on that fuel at the end of the year (not the sales tax just the state and federal)