philly
solid fixture here in the forum
heres a great perspective from a few years back off the popular hot rodding forums: i pulled the relevant info from this link
http://forums.popularhotrodding.com/70/ ... page2.html
Flexfuel E85 => 105 octane ethanol alcohol
Mr Hunkins, I believe there is a small block motor rendition that has not been done yet. One that exploits the 105 octane feature of E85. This is essentially alcohol racing fuel which is becoming more and more available at the pump in Midwest gas stations as Flexfuel, and the availability is spreading across the rest of the nation rather quickly.
http://www.e85fuel.com/index.php
I would especially like to see an updated version of the LS1, LSx, Gen III engine Norm Brandes of WESTECH Auto in Wisconsin built for a Camaro 302 show car for GM about 5 years ago. The motor was I believe a 5.7 block with a 4.8 crank shaft and rods.
http://www.ttspowersystems.com/articles/7/index.htm
http://www.camaroz28.com/articles/302camaro/index.shtml
http://www.yearone.com/enthusiast/tours ... amaro.html
http://www.westechauto.com/tech_talk/ar ... 5_01_1.htm
If you used a 4.8 crank and rods in a 6.0 block, the cid becomes approximately 327 cid with a rather large rod/stroke ration of 6.275/3.268 = 1.92:1
If you started with a LS7 bore (4.125) and the 4.8 stroke (3.268) you get a nice 349.4 (5.7L) engine with a piston speed of about 4350 @ 8000. That was the formula for the first CTS-VR race car a couple of years ago. They cleaned up at Sebring, but got a rev limit (7100 I think) and some weight added right after that.
The LSx cranks are very strong, especially the short stroke one. A 1.92 Rod/Stroke ratio isn't out of line at all. That's just about where Cup engines run. Nothing magic about it. It just fits well in the block with a 3.26 stroke. This short stroke combined with high compression and 105 octane fuel would be a flash back to the rev happy 283-302 cube SBC in the 50s-60s.
An interesting side bar to this type of engine build up would be how to get the GM OBDII to operate on E85 only, not full of Flexfuel compromises. As far as all the alcohol compatible materials and fuel system components, I believe GM has already figured this out. You can mix and match fuel pumps, injectors, and other fuel system components from GM’s fleet of E85 compatible vehicles. It is extensive.
http://www.gm.com/company/onlygm/energy_flexfuel.html#
http://en.wikipedia.org/wiki/E85
Why E85 only?
1) E100 (100% ethanol)can be run in motors with a compression ratio as high as 19.5:1. Really, 19.5! Determining the upper compression limits of E85 when used in a purpose built motor should be of interest to readers.
http://www.hybridcars.com/blogs/hyview/ ... om-ethanol
2. E85 has a much higher evaporative cooling power than gasoline so the intake air charge in the cylinder is significantly cooler that it is with a comparable mixture of gasoline --- that means higher VE.
3. E85 has an octane of 105!!!
4. E85 (ethanol) burns faster than gasoline but has a slightly longer ignition delay during the slow burn phase of combustion so the engine does not do as much negative work fighting rising cylinder pressures due to large ignition advances. The total ignition advance for E85 is almost identical to the ideal advance for gasoline so it does not cause the ECU problems when you mix them.
5. At proper mixture you actually are releasing more energy in the cylinder due to the higher quantity of fuel you can burn. (Ethanol can burn efficiently at much richer mixtures than gasoline can) That means about a 5% increase in energy release all by itself.
6. Peak combustion pressures are actually lower for ethanol than for gasoline but the cylinder pressures stay higher longer, so you have more (longer) crank angle that is usable by the engine. This lower peak cylinder pressure also helps with detonation control. With this characteristic, I think having a longer rod to stroke ratio, which will make the piston stall somewhat longer at TDC, will help.
A piston with a stock 5.7 or 6.0 pin height will be down in the hole 0.177" when using a 4.8 crankshaft and rod. I sent a note to Diamond Racing and they responded they would be able to make one of their standard catalog pistons (dished, flat top, or 10cc dome) with the pin hole moved down 0.177 to compensate. I believe other piston manufacturers could accomplish the same.
As long as custom pistons are necessary, there is a possibility of using even longer rods. Yes they are available. Forged rods at 6.348" are available from here -
https://www.shop.crankshaftdepot.com/di ... egoryId=89
These longer rods are stronger than stock, and this added length reduced the piston height difference from 0.177 to only 0.073.
With the longer rods, the rod/stroke ratio increases from 1.92:1 to 1.94:1, which might be a good thing for the combustion properties of alcohol.
These forged rods used with forged Diamond pistons should be good for piston speeds of over 4300 ft/minute. With the 4.8 crank stroke, this calculates to be a short block capable of nearly 8000 rpms. Set the rpm redline to 7500 rpms to provide a safety cushion, find a camshaft with a power peak between 6500 and 7000, and this would be a very rev happy motor. The 105 octane E85 should allow one to select a camshaft with a low valve overlap so the cylinder pressure is high at low rpms. This would be impossible to do with a conventional gas motor as knocking and preignition would be tremendous with high cylinder pressure. If you could get David Vizard to work with Norm Brandes to find a camshaft profile that would allow for a 850 idle rpm with the GM OBDII PCM as Norm accomplished on his concept 302, and a red line of 8000rpm, how cool would that be?
If this all came together, this would be a rev friendly motor in the spirit of, and improved upon, the '67-'69 Z28 302 Trans Am motors. This would be a great motor build to associate with the upcoming new Camaro.
EDIT - Here is something to look into that is happening later this week at the Engine Rebuilders Association Show in Indiana -
http://www.aera.org/expo2006.aspx
http://www.aera.org/docs/other/E85Rules.pdf
EDIT 2 - I found the following from one of your archived articles by Mr Vizard on the benifits of high compression. I think it gives support to a high rpm motor that makes good power at higher rpm's yet retains good torque at lower rpm's. How far a camshaft designer could extend this range using E85 would be a very interesting study.
http://www.popularhotrodding.com/tech/0 ... atio_tech/
"... a high-compression cylinder produces better power and fuel economy. It is not just because the charge is squeezed harder and the resulting combustion pressure goes up, but also because the higher expansion ratio allows more energy to be extracted from the original high-pressure charge."
"Because the high compression cylinder makes its power much earlier on in the power stroke there are other implications we can take advantage of. The most obvious is that we can apply the earlier exhaust valve opening needed for higher rpm output without significantly impacting the engines low speed output. Using as much compression as circumstances will allow makes dual pattern cams work at their best."
Read more: http://forums.popularhotrodding.com/70/ ... z2rk9v5MDJ
Here I will provide you a great example of one such build that reflects alot of the ideas used in the above statement: from LS1TECH, Project "redheaded screamer" built and owned by jakson of TPI Specialties:
general overview of the combination:
"Iron "5.3" 332ci on E85, ARP head/main studs, custom coated diamond pistons, callies rods, stock crank.
Ported LS3 heads, LS3 hollow stem intake valves, LY6 inconel exhausts, PRC EHT springs
LS9 headgaskets
239/243 .625/.625 116lsa Comp Cam
Morel link bar lifters, 3/8 pushrods
9.5:1 Compression Ratio
Some may be wondering how I am going to fit LS3 heads on a little old 5.3. Well, I'm using a 6.0 block .020 over, and a stock 4.8 3.267" crank.
Going with the 4.8 crank mostly to try something different, boost will be my replacement for displacement in this case. Somewhat similar to the new COPO Camaro 5.3 engine setup. Hoping to turn it 7500+, obviously the stock intake will be the limiting factor somewhere along the line.
I will most likely go to a single plane later on. Just going to get it running in this configuration first, work out the bugs and go from there."
this combo did him good for 1096 hp @ 7600 rpm at 20 psi through an 88mm turbocharger
if you want to follow jakson's saga:
http://ls1tech.com/forums/forced-induct ... 5-7-a.html
theres dyno videos with graphs on pages 5 and 7 of that thread.
In case you all decide to dabble in the LS family of small block chevrolet engines heres some information for you all. nothing too crazy just trying to get the thoughts flowing...
GMHTP article with brief history and general parts interchangeability:
http://www.gmhightechperformance.com/te ... ewall.html
Gen III factory cylinder head comparo by car craft:
http://www.carcraft.com/techarticles/cc ... ewall.html
Cathedral port vs Rectangular port heads:
http://www.carcraft.com/techarticles/cc ... ort_heads/
its important to note (and if you read the GM high tech article above you would know) that if you have cathedral port heads you need an intake for those heads, and if you have rectangular port heads you need an intake for those. they are NOT interchangeable.
factory camshaft swap comparison with dyno results and cam specs:
http://www.carcraft.com/techarticles/13 ... omparison/
hot rod magazine ls cylinder head comparo genIII and genIV aftermarket heads with flow bench and dyno data included: 10 sets of aftermarket heads, lots of info:
http://www.hotrod.com/techarticles/engi ... ewall.html
http://forums.popularhotrodding.com/70/ ... page2.html
Flexfuel E85 => 105 octane ethanol alcohol
Mr Hunkins, I believe there is a small block motor rendition that has not been done yet. One that exploits the 105 octane feature of E85. This is essentially alcohol racing fuel which is becoming more and more available at the pump in Midwest gas stations as Flexfuel, and the availability is spreading across the rest of the nation rather quickly.
http://www.e85fuel.com/index.php
I would especially like to see an updated version of the LS1, LSx, Gen III engine Norm Brandes of WESTECH Auto in Wisconsin built for a Camaro 302 show car for GM about 5 years ago. The motor was I believe a 5.7 block with a 4.8 crank shaft and rods.
http://www.ttspowersystems.com/articles/7/index.htm
http://www.camaroz28.com/articles/302camaro/index.shtml
http://www.yearone.com/enthusiast/tours ... amaro.html
http://www.westechauto.com/tech_talk/ar ... 5_01_1.htm
If you used a 4.8 crank and rods in a 6.0 block, the cid becomes approximately 327 cid with a rather large rod/stroke ration of 6.275/3.268 = 1.92:1
If you started with a LS7 bore (4.125) and the 4.8 stroke (3.268) you get a nice 349.4 (5.7L) engine with a piston speed of about 4350 @ 8000. That was the formula for the first CTS-VR race car a couple of years ago. They cleaned up at Sebring, but got a rev limit (7100 I think) and some weight added right after that.
The LSx cranks are very strong, especially the short stroke one. A 1.92 Rod/Stroke ratio isn't out of line at all. That's just about where Cup engines run. Nothing magic about it. It just fits well in the block with a 3.26 stroke. This short stroke combined with high compression and 105 octane fuel would be a flash back to the rev happy 283-302 cube SBC in the 50s-60s.
An interesting side bar to this type of engine build up would be how to get the GM OBDII to operate on E85 only, not full of Flexfuel compromises. As far as all the alcohol compatible materials and fuel system components, I believe GM has already figured this out. You can mix and match fuel pumps, injectors, and other fuel system components from GM’s fleet of E85 compatible vehicles. It is extensive.
http://www.gm.com/company/onlygm/energy_flexfuel.html#
http://en.wikipedia.org/wiki/E85
Why E85 only?
1) E100 (100% ethanol)can be run in motors with a compression ratio as high as 19.5:1. Really, 19.5! Determining the upper compression limits of E85 when used in a purpose built motor should be of interest to readers.
http://www.hybridcars.com/blogs/hyview/ ... om-ethanol
2. E85 has a much higher evaporative cooling power than gasoline so the intake air charge in the cylinder is significantly cooler that it is with a comparable mixture of gasoline --- that means higher VE.
3. E85 has an octane of 105!!!
4. E85 (ethanol) burns faster than gasoline but has a slightly longer ignition delay during the slow burn phase of combustion so the engine does not do as much negative work fighting rising cylinder pressures due to large ignition advances. The total ignition advance for E85 is almost identical to the ideal advance for gasoline so it does not cause the ECU problems when you mix them.
5. At proper mixture you actually are releasing more energy in the cylinder due to the higher quantity of fuel you can burn. (Ethanol can burn efficiently at much richer mixtures than gasoline can) That means about a 5% increase in energy release all by itself.
6. Peak combustion pressures are actually lower for ethanol than for gasoline but the cylinder pressures stay higher longer, so you have more (longer) crank angle that is usable by the engine. This lower peak cylinder pressure also helps with detonation control. With this characteristic, I think having a longer rod to stroke ratio, which will make the piston stall somewhat longer at TDC, will help.
A piston with a stock 5.7 or 6.0 pin height will be down in the hole 0.177" when using a 4.8 crankshaft and rod. I sent a note to Diamond Racing and they responded they would be able to make one of their standard catalog pistons (dished, flat top, or 10cc dome) with the pin hole moved down 0.177 to compensate. I believe other piston manufacturers could accomplish the same.
As long as custom pistons are necessary, there is a possibility of using even longer rods. Yes they are available. Forged rods at 6.348" are available from here -
https://www.shop.crankshaftdepot.com/di ... egoryId=89
These longer rods are stronger than stock, and this added length reduced the piston height difference from 0.177 to only 0.073.
With the longer rods, the rod/stroke ratio increases from 1.92:1 to 1.94:1, which might be a good thing for the combustion properties of alcohol.
These forged rods used with forged Diamond pistons should be good for piston speeds of over 4300 ft/minute. With the 4.8 crank stroke, this calculates to be a short block capable of nearly 8000 rpms. Set the rpm redline to 7500 rpms to provide a safety cushion, find a camshaft with a power peak between 6500 and 7000, and this would be a very rev happy motor. The 105 octane E85 should allow one to select a camshaft with a low valve overlap so the cylinder pressure is high at low rpms. This would be impossible to do with a conventional gas motor as knocking and preignition would be tremendous with high cylinder pressure. If you could get David Vizard to work with Norm Brandes to find a camshaft profile that would allow for a 850 idle rpm with the GM OBDII PCM as Norm accomplished on his concept 302, and a red line of 8000rpm, how cool would that be?
If this all came together, this would be a rev friendly motor in the spirit of, and improved upon, the '67-'69 Z28 302 Trans Am motors. This would be a great motor build to associate with the upcoming new Camaro.
EDIT - Here is something to look into that is happening later this week at the Engine Rebuilders Association Show in Indiana -
http://www.aera.org/expo2006.aspx
http://www.aera.org/docs/other/E85Rules.pdf
EDIT 2 - I found the following from one of your archived articles by Mr Vizard on the benifits of high compression. I think it gives support to a high rpm motor that makes good power at higher rpm's yet retains good torque at lower rpm's. How far a camshaft designer could extend this range using E85 would be a very interesting study.
http://www.popularhotrodding.com/tech/0 ... atio_tech/
"... a high-compression cylinder produces better power and fuel economy. It is not just because the charge is squeezed harder and the resulting combustion pressure goes up, but also because the higher expansion ratio allows more energy to be extracted from the original high-pressure charge."
"Because the high compression cylinder makes its power much earlier on in the power stroke there are other implications we can take advantage of. The most obvious is that we can apply the earlier exhaust valve opening needed for higher rpm output without significantly impacting the engines low speed output. Using as much compression as circumstances will allow makes dual pattern cams work at their best."
Read more: http://forums.popularhotrodding.com/70/ ... z2rk9v5MDJ
Here I will provide you a great example of one such build that reflects alot of the ideas used in the above statement: from LS1TECH, Project "redheaded screamer" built and owned by jakson of TPI Specialties:
general overview of the combination:
"Iron "5.3" 332ci on E85, ARP head/main studs, custom coated diamond pistons, callies rods, stock crank.
Ported LS3 heads, LS3 hollow stem intake valves, LY6 inconel exhausts, PRC EHT springs
LS9 headgaskets
239/243 .625/.625 116lsa Comp Cam
Morel link bar lifters, 3/8 pushrods
9.5:1 Compression Ratio
Some may be wondering how I am going to fit LS3 heads on a little old 5.3. Well, I'm using a 6.0 block .020 over, and a stock 4.8 3.267" crank.
Going with the 4.8 crank mostly to try something different, boost will be my replacement for displacement in this case. Somewhat similar to the new COPO Camaro 5.3 engine setup. Hoping to turn it 7500+, obviously the stock intake will be the limiting factor somewhere along the line.
I will most likely go to a single plane later on. Just going to get it running in this configuration first, work out the bugs and go from there."
this combo did him good for 1096 hp @ 7600 rpm at 20 psi through an 88mm turbocharger
if you want to follow jakson's saga:
http://ls1tech.com/forums/forced-induct ... 5-7-a.html
theres dyno videos with graphs on pages 5 and 7 of that thread.
In case you all decide to dabble in the LS family of small block chevrolet engines heres some information for you all. nothing too crazy just trying to get the thoughts flowing...
GMHTP article with brief history and general parts interchangeability:
http://www.gmhightechperformance.com/te ... ewall.html
Gen III factory cylinder head comparo by car craft:
http://www.carcraft.com/techarticles/cc ... ewall.html
Cathedral port vs Rectangular port heads:
http://www.carcraft.com/techarticles/cc ... ort_heads/
its important to note (and if you read the GM high tech article above you would know) that if you have cathedral port heads you need an intake for those heads, and if you have rectangular port heads you need an intake for those. they are NOT interchangeable.
factory camshaft swap comparison with dyno results and cam specs:
http://www.carcraft.com/techarticles/13 ... omparison/
hot rod magazine ls cylinder head comparo genIII and genIV aftermarket heads with flow bench and dyno data included: 10 sets of aftermarket heads, lots of info:
http://www.hotrod.com/techarticles/engi ... ewall.html