[grandville455]

Originally Posted by PAUL K

Already did.... Bent two rods and popped a head gasket instantly. That was 10.5 with 93. Now after reading this thread I believe my mistake was the 93 octane. Most likely should have used 87 to keep it safe.

Lmao!!

[PAUL K]

Originally Posted by grandville455

Lmao!!

It was kinda funny.... I wanted to jump on the new combination through second gear to see how it felt. I came off the light heading West at Butterfield and Rt.59 as soon as I stabbed the throttle all Hell let use, I lifted instantly. A friend has a body shop right there and was standing by the over head door closing up the shop. I coasted into the shops driveway right up to the door he was standing at, smoking like crazy and peeing anti-freeze all over the place and said "hi Steve" like nothing was wrong.... If only I would've used 87 octane..... Or more compression!

[opeliac]

Originally Posted by PAUL K

Already did.... Bent two rods and popped a head gasket instantly. That was 10.5 with 93. Now after reading this thread I believe my mistake was the 93 octane. Most likely should have used 87 to keep it safe.

It seems like you may be calling some of us a liar????

[PAUL K]

Originally Posted by opeliac

It seems like you may be calling some of us a liar????

Nah.... I learned something from this thread. 14.5:1 is a pump gas friendly compression ratio.

[opeliac]

Originally Posted by PAUL K

Nah.... I learned something from this thread. 14.5:1 is a pump gas friendly compression ratio.

Well, there is a difference in being a perfect scenario, and being able to do something...The 14.5:1 496 easily drove the guy all over his area when he wanted to go, was able to do some burnouts without destroying it, and could really get wild when he'd add some good fuel to the tank...It did exactly what he wanted...

My old 11.8:1 Pontiac was a car that i drove more than plenty...It made many 35-70 mile trips, all on cheap unleaded fuel...If I was building something to drive on trips, it wouldnt be those combinations...But, for toys, high compression pump gas cars have been around for many decades...

I'm sorry that you blew yours up due to pump gas, which I will call BS on...You aint gonna break two rods due to some detonation...Try again.

EDIT: I meant bend two rods...

[PAUL K]

Originally Posted by opeliac

Well, there is a difference in being a perfect scenario, and being able to do something...The 14.5:1 496 easily drove the guy all over his area when he wanted to go, was able to do some burnouts without destroying it, and could really get wild when he'd add some good fuel to the tank...It did exactly what he wanted...
.

So now it requires better than 93 octane to run?

Originally Posted by opeliac

My old 11.8:1 Pontiac was a car that i drove more than plenty...It made many 35-70 mile trips, all on cheap unleaded fuel...If I was building something to drive on trips, it wouldnt be those combinations...But, for toys, high compression pump gas cars have been around for many decades...
.

So now you drove it a lot just not daily?

Originally Posted by opeliac

I'm sorry that you blew yours up due to pump gas, which I will call BS on...You aint gonna break two rods due to some detonation...Try again.
.

I didn't blow it up.... Bent two rods and popped a head gasket. For being a turbo guy you might want to familiarize yourself with detonation.... Speaking of turbos how is your build coming along?

You can judge for yourself if the rods look bent... I won't be changing the details on my story as we go along.... Mine actually happened

[hurryinhoosier62]

Originally Posted by PAUL K

So now it requires better than 93 octane to run?



So now you drove it a lot just not daily?



I didn't blow it up.... Bent two rods and popped a head gasket. For being a turbo guy you might want to familiarize yourself with detonation.... Speaking of turbos how is your build coming along?

You can judge for yourself if the rods look bent... I won't be changing the details on my story as we go along.... Mine actually happened

Maybe I should have an old acquaintance of mine , Mike Nixon who owns Vintage V-12s, share some of his stories about how detonation in 4,000hp air racing engines on 115/145 Avgas bends more than a couple of connecting rods. They were only running 120 inches of manifold pressure( twice the stock limit). Too bad my old mentor and friend Bud Brown is deceased. He had a really good story about a 250 Offy that went into detonation on the dyno at WOT. Bud said the only things left were the the flywheel, the cams and the gear drive.

[opeliac]

Originally Posted by PAUL K

So now it requires better than 93 octane to run?



So now you drove it a lot just not daily?



I didn't blow it up.... Bent two rods and popped a head gasket. For being a turbo guy you might want to familiarize yourself with detonation.... Speaking of turbos how is your build coming along?

You can judge for yourself if the rods look bent... I won't be changing the details on my story as we go along.... Mine actually happened

Every single bit of mine happened, and if you'd like to put your money where your mouth is, it can be proven...

The 496 was able to drive around and get goofy a little on pump gas...If he wanted to race it hard, I told him to put good fuel in it...That didnt mean that he couldnt enjoy it on pump gas though...

I drove mine through every season that we have here in Kentucky...Sometimes it was the only thing that was running, and other times it sat while I drove other vehicles...It made the trip from Louisville to Indianapolis, ON PUMP GAS!!!!! So, if that doesnt clarify it enough for you, then oh well...

As for my turbo combo...Its been at BES since last November...I'm running a friends nitrous car this season so i'm not rushing Tony on mine...The chassis is in line to get some sheet metal work done, then hopefully it'll progress over this winter...

It really irks me when guys like you act like an engine with compression cant be driven on pump gas...We've done that stuff since the 80s, with dang near every brand of engine thats worth racing...

As for your bent rods...Are you truly trying to say that the detonation bent those rods??? Or, did you lose a head gasket and hydraulic'd the engine???

[Dragncar]

If that 496 actually ran better on race gas then pump gas that means it was detonating. No way around that. The engine was being harmed.
A true pump gas engine will always run better with pump gas then race gas.
There is more energy in 87 octane than 116 octane. The 116 just wont self ignite under pressure so you make more power, IF you have the compression to take advantage of it.

[PAUL K]

Originally Posted by opeliac

Every single bit of mine happened, and if you'd like to put your money where your mouth is, it can be proven...

The 496 was able to drive around and get goofy a little on pump gas...If he wanted to race it hard, I told him to put good fuel in it...That didnt mean that he couldnt enjoy it on pump gas though...

I drove mine through every season that we have here in Kentucky...Sometimes it was the only thing that was running, and other times it sat while I drove other vehicles...It made the trip from Louisville to Indianapolis, ON PUMP GAS!!!!! So, if that doesnt clarify it enough for you, then oh well...

As for my turbo combo...Its been at BES since last November...I'm running a friends nitrous car this season so i'm not rushing Tony on mine...The chassis is in line to get some sheet metal work done, then hopefully it'll progress over this winter...

It really irks me when guys like you act like an engine with compression cant be driven on pump gas...We've done that stuff since the 80s, with dang near every brand of engine thats worth racing...

As for your bent rods...Are you truly trying to say that the detonation bent those rods??? Or, did you lose a head gasket and hydraulic'd the engine???

Sorry you get irked so easily. I don't like it when folks tell fairy tales about 14.5 compression works with 93 octane but leave out the details that the timing needs to be changed, the jetting needs to be changed and you can't give it more than 1/8 throttle.

I'm not sure how that helped the OP out one bit. It's not like he asked, how do I drive my 15:1 compression race car home from the track because someone stole my tow vehicle and all I have access to is 89 octane.


When I was a kid (now this was back in the 80's) I had a 455 with 16 d-port heads on it. During the week I dropped the timing and ran 93 octane to drive it to work. Come the weekend I ran it on Av-gas and won a lot of races. I just don't think it's right to imply it ran fine on pump gas. Unless your idea of running fine is being down 70 horsepower from where the engine should be.

Glad your making progress on the turbo project. Hopefully you figure out its octane requirements before you put your foot to the floor. Those turbo engines aren't very forgiving.

Here's what happened with the bent rods. The engine detonated because it didn't have enough octane. That blew a head gasket and let water in two cylinders. Water doesn't compress so the rods were the weak link and bent. If the fuel had enough octane to prevent detonation, the head gasket would not of failed. The engine would most likely be running today with the same rods. Instead the short block is still together with the replacement rods running low eleven's in a Trans Am with a pump gas friendly compression ratio.

[PAUL K]

Originally Posted by Dragncar

If that 496 actually ran better on race gas then pump gas that means it was detonating. No way around that. The engine was being harmed.
A true pump gas engine will always run better with pump gas then race gas.
There is more energy in 87 octane than 116 octane. The 116 just wont self ignite under pressure so you make more power, IF you have the compression to take advantage of it.

I remember a fellow with a big dually that had two fuel tanks. He filled one tank with high octane and the other with 87. Made a couple of passes at the track with the 87 and then switched to the high octane tank and slowed down.... He just had to prove it for himself.

[turbo69bird]

Idk about 14 to 1 but water meth injection can be a really good compensator . Here in CT we don’t have E85 anywhere. Don’t ask why , the answer is This state is stupid!
I run 12 to 1 w 100ll I wouldn’t run it on 93 octane that’s for sure. If was to try and get lower and lower if have a AFR gauge and I’d start blending 5 percent 93 then 10 percent etc . I’d creep up on the tune that way all white
Monitoring AFR and I’d keep it fat and lazy while I did it. It’s so easy to burn a ring land or beat the bearings out of it.

[slowbird]

Originally Posted by grandville455

Why not just switch over to E85 and be done with it..

I don't think he wants to slow down a couple tenths, lol.

[Dragncar]

I see no benefit in running any engine that lights off well before TDC. Even if its a beefy brand X engine that can take more abuse.
I am a pump gas guy so the engine I just finished is 11.5 -1 CR and the plan is for it to run on all gas 92 we can get here. Right now I have 99 octane fuel in it. 2 gallons of 110 mixed with 3 gallons of 92.
It seems to run great but the engine has less than 10 minutes on it. I went to put a timing light on it, set it at 29 total (High Ports) and let if fully warm up and run the valves. But had to go to work early.

Once the engine settles in I will pull the 1050 off and put a 850 back on her and get a baseline ET-MPH with the 99 octane.
Then try one gallon of 110 mixed with 4 gallons of 92 and that will get me 95.6 octane.
If it runs the same or better I will try straight 92 and I will stay with it only if the car does not slow down.
But I am not going to detonate this engine under any circumstance.
See how much power I can make with a stock block and a 850. It should hold me to 650HP or so you would think. Kinda hard to blow up a nicely done stock block at that power level.
Put the 1050 on .......maybe. Not sure yet.
But hey, I know a guy who has a Ford with 14-1 and drives it on CA 91. I am not that brave. This stuff is too expensive to take chances on.

[opeliac]

Originally Posted by PAUL K

Sorry you get irked so easily. I don't like it when folks tell fairy tales about 14.5 compression works with 93 octane but leave out the details that the timing needs to be changed, the jetting needs to be changed and you can't give it more than 1/8 throttle.

I'm not sure how that helped the OP out one bit. It's not like he asked, how do I drive my 15:1 compression race car home from the track because someone stole my tow vehicle and all I have access to is 89 octane.


When I was a kid (now this was back in the 80's) I had a 455 with 16 d-port heads on it. During the week I dropped the timing and ran 93 octane to drive it to work. Come the weekend I ran it on Av-gas and won a lot of races. I just don't think it's right to imply it ran fine on pump gas. Unless your idea of running fine is being down 70 horsepower from where the engine should be.

Glad your making progress on the turbo project. Hopefully you figure out its octane requirements before you put your foot to the floor. Those turbo engines aren't very forgiving.

Here's what happened with the bent rods. The engine detonated because it didn't have enough octane. That blew a head gasket and let water in two cylinders. Water doesn't compress so the rods were the weak link and bent. If the fuel had enough octane to prevent detonation, the head gasket would not of failed. The engine would most likely be running today with the same rods. Instead the short block is still together with the replacement rods running low eleven's in a Trans Am with a pump gas friendly compression ratio.

A fairy tale is something that didnt happen...You can choose to believe what you want, we've done it and will do it again...

As for your car...If you detonated enough to lose a head gasket and hydraulic the engine, you obviously wasnt very smart back then.

[opeliac]

Originally Posted by Dragncar

If that 496 actually ran better on race gas then pump gas that means it was detonating. No way around that. The engine was being harmed.
A true pump gas engine will always run better with pump gas then race gas.
There is more energy in 87 octane than 116 octane. The 116 just wont self ignite under pressure so you make more power, IF you have the compression to take advantage of it.

Like we really gave a crap if it "harmed" the engine...LOL...It did EXACTLY what we wanted it to do, and it did it quite well while doing it...

[opeliac]

For the record...The OP asked if he could drive his car to local cruises on 91 octane, and he also asked about trying to make 1 pass on the 91 octane fuel...NOWHERE in his post did he ask if he could run his fastest pass on pump gas...

My old junk ran mid 6.60s@3680lbs, and ran a 6.91 when I drove it down there and ran it on cheap pump gas...I wasnt trying to set a record, just show that it would do it...

That was around 1994...The engine is freshly machined, sitting on the stand waiting to be put back together...If I ever put it back in something, i'll throw crap gas in it and drive it just about anywhere you'd like to go.

[PAUL K]

Originally Posted by opeliac

A fairy tale is something that didnt happen...You can choose to believe what you want, we've done it and will do it again...

You already discredited your own version of the fairy tale.... If you had an understanding of detonation you would see right through your own story. It's okay to play "make believe". You just shouldn't do it on a public forum.... Other folks most likely won't play along.

Originally Posted by opeliac

As for your car...If you detonated enough to lose a head gasket and hydraulic the engine, you obviously wasnt very smart back then.

That might be true but I've always been smart enough to keep my chit running over the years. Never had to sit on the sidelines with my "unit" in my hand fantasizing about things that never happened.

[opeliac]

Originally Posted by PAUL K

You already discredited your own version of the fairy tale.... If you had an understanding of detonation you would see right through your own story. It's okay to play "make believe". You just shouldn't do it on a public forum.... Other folks most likely won't play along.




That might be true but I've always been smart enough to keep my chit running over the years. Never had to sit on the sidelines with my "unit" in my hand fantasizing about things that never happened.

What the heck did I discredit? I posted the facts, and if you want to step up to the plate, i'm not opposed to proving it to you...It wasnt hard to do at all...

[Jay S]

Lol…The not so bright new tanker truck driver filled the Road Diesel tank pumps at the local service station with gasoline a while back. So I guess quite a few of us around here have ran some turbo charged 16:1 engines on pump gas.