What octane can I run in a stock 2.9l v6?

[Dirtman]

My mustang is carbed with all original seals and gaskets and lines. E10 would chew through that car like a pack of rabid beavers. No sireee bob... she gets gasoline, pure pure gasoline. Just like god intended. It doesn't need 100 octane but it's all I can get from the marine pump. It is 10.5:1 compression so it's close enough to what it needs.

 

[rusty ol ranger]

My mustang is carbed with all original seals and gaskets and lines. E10 would chew through that car like a pack of rabid beavers. No sireee bob... she gets gasoline, pure pure gasoline. Just like god intended. It doesn't need 100 octane but it's all I can get from the marine pump. It is 10.5:1 compression so it's close enough to what it needs.

Next time i rebuild the carb on my 77 its getting the ethanol compatiable carb kit. Its more expensive but im tired of rebuilding it every 2 years.

 

[Dirtman]

That just a carb with better seals and gaskets? Never heard of them.

 

[rusty ol ranger]

That just a carb with better seals and gaskets? Never heard of them.

Im not sure whats "better" about it. But im gonna give it a shot at somepoint.

Currently the 77 has sat in my driveway for the last 8 months or so. Hasnt even been started.

 

[cbxer55]

Im not saying it isnt a band aid. But seeing as how ive done it now for 3 or 4 years and have not had any ill effects id say yay for band aids.

And yes, the oil thing is also a good point. But why would i tear down an otherwise fine running engine when i can just pour in thicker oil?

I agree. I have done the Sea Foam inhaled through the brake booster hose twice trying to clean carbon deposits, it didn't do a thing, still pinged. So yeah, hurray for "band aids". I'll keep using high octane fuel if that's what it takes to not hear it ping. I am not tearing it down when it runs just fine. Also, I do run 20w-50 oil in the thing, have for 20 years. The original oil cap said 10W-30. 20W-50 is not a terrible thing in a 10W-30 vehicle. My Clymer manual says theo nly difference is a little higher cold temperature, but still well below zero, which we don't get here. And, as I said, been running ethanol in the thing for years to cure cold start issues, never hurt a thing that I can tell. Even with the lean codes, the thing runs awesome. So evidently band aids work. Not tearing it apart when it runs as good as it does. Not now or ever.

 

[Dirtman]

Try using the seafoam spray can through the throttle body. Works alot better than using the regular cans and sucking it into a vacuum line like the brake booster and remeber to let it hot soak when the can is almost empty. When it's almost out, flood it till it stalls and let it sit for 15-20 minutes before restarting it. Then go run the piss out of it while fogging up your neighborhood. I've seen that stuff do wonders this way. And throw a can in the tank once a year as well.

 

[cbxer55]

Pull your heads and have them walnut shell blasted or soda blasted. You have black death happening in that 3.Slow. Only a matter of time before she starts handing you real problems.

Hell. I'll even soda blast em if you want to ship them.

What real problems? I've been dealing with this since like 2004 or so. Never caused me any problems. The truck still gets me where I want to go, or need to go, no problemo. Not tearing it apart to fix it when it runs so darn good. It really does run good, not making that up. I don't have the time or inclination to tear it apart. I need it every day. Yeah, I have a Lightning. It's not a daily driver, it's a garage queen. Only driven on the nicest of days, maybe 2000 miles a year, or less. It's not an option to drive that in bad weather to fix my beater Ranger. When/if it does give me major problems, it's gone, outta here and I'll get something else. I've had it since January 2000. Even then, when it only had 10,000 miles on it, it still pinged on 87 or 89. It's not gotten worse, or better in all these years.

 

[cbxer55]

Try using the seafoam spray can through the throttle body. Works alot better than using the regular cans and sucking it into a vacuum line like the brake booster and remeber to let it hot soak when the can is almost empty. When it's almost out, flood it till it stalls and let it sit for 15-20 minutes before restarting it. Then go run the piss out of it while fogging up your neighborhood. I've seen that stuff do wonders this way.

That's what I did with the brake booster method. Ran it til it stalled, let it sit like half an hour. When started, it smoked out the neighborhood. Both times. Big huge stinky cloud. It was kind of fun, to tell the truth. Yeah, maybe I'll try the spray method this weekend.

 

[cbxer55]

My mustang is carbed with all original seals and gaskets and lines. E10 would chew through that car like a pack of rabid beavers. No sireee bob... she gets gasoline, pure pure gasoline. Just like god intended. It doesn't need 100 octane but it's all I can get from the marine pump. It is 10.5:1 compression so it's close enough to what it needs.

Yeah, I hear that. My Lightning will never see ethanol, just pure 93 octane. It does fine on that with a Magnum Powers blower and upped boost from stock. EGR deleted. Cat back Borla exhaust.

 

[Dirtman]

Do you have to go somewhere special for pure gasoline? In NJ only airports and marinas are allowed to sell pure gasoline.

 

[cbxer55]

Do you have to go somewhere special for pure gasoline? In NJ only airports and marinas are allowed to sell pure gasoline.

Here in Oklahoma, no. Most gas stations sell pure gas. Those that sell ethanol, it's only 87. And they offer both pure gas and E10. All gas over 87 is non ethanol. On Cue stations have the biggest selection, including E85. The pump handle is color coded. Yellow for E85, black for E10, red for all others. The 93 I run in my vehicles comes from only one station, three miles from me. He has to have the 93 trucked in from Arkansas. otherwise it's not available.

I was born and raised in N.J. My parents moved to California in 1976, when I was 15. I moved to Oklahoma in 2002. Been here since. Glad my parents left Jersey when they did. Constitutional Carry just became the law in Oklahoma, can carry a firearm without a permit, concealed or open carry. It's nice, don't have to spend $200 for a ten year permit any longer.

 

[adsm08]

There is one loophole here. And I hate to say it because it'll probably cause someone to **** something up.

But, if you adjust your distributor to 12 degrees (up from base timing at 10 degrees) and run 89 octane you will see a bump in power.

Octane is a measure of detonation resistant properties.

Significant timing advances causes detonation

Adjusting timing massively increases the performance in the 2.9.

If you **** it up, you will **** up your engine.

I once had a 2.9 with a cam, ran it on 87 regular, at about 20* advance.

It did not ping.

 

[adsm08]

Do you have to go somewhere special for pure gasoline? In NJ only airports and marinas are allowed to sell pure gasoline.

I have a regular old gas station 1.5 miles from my house that sells it.

I run it in the lawn mowers. I did the math on running it in the cars, but its almost $4/gallon and the mileage increase I expect to see doesn't offset the increased cost of running that over running E-10 at ~$2.75/gal.

 

[PetroleumJunkie412]

I once had a 2.9 with a cam, ran it on 87 regular, at about 20* advance.

It did not ping.

A cammed 2.9 you say??

 

[adsm08]

A cammed 2.9 you say??

View attachment 33162

I don't have the engine. I don't have the cam's spec card. I DO have it's twin, however it was damaged in a garage flood and is not useable.