Changes in fuel octane
 

I was told by an old offshore racer that if a 900 HP fuel injected blower motor is set up and tuned for 93 octane that if you went out and put some 112 in it I could seriously damage the motor. This goes against everything I know. Less octane, problems. More octane, no problems. Also, some high octane fuels have no lead, some do. Isn't lead better for cushioning the valves? We're can I find a vp or other station that sells high octane in Havasu, that I can get my 45 ft trailer with boat on it in and out easily?

To explain it simply, the compressed air/fuel mixture in the cylinder burns, it doesn't "explode"...Exploding is detonation, and wreaks havoc on the motor. The higher the octane the (laymans terms) slower it burns and reduces detonation. But since it is burning slower it is actually producing less "power". so Octane doesn't make power, it allows you to do things like add boost, advance timing, higher compression ratios etc that make power. Simply running higher octane than needed makes less power.

As for lead, (and Im dating myself) leaded fuel cusioned valve seats amongst other things. Valve seat material changed so lead was no longer needed.

Rick, We rent a 30 X 100 ft. storage unit at The Islander Storage for the week. We run the boats, get them back on the trailer and fuel in town. We clean the boats and get them ready for the next day. The water is super hard and the minerals waterspot horribly. Doug

Trailer not a bad idea! Home I rented has huge flat driveway so I can leave boat there ( with trailer lock). Where can I get hi octane fuel? Last time there I had my warlock 31sxt and could easily enter and exit a local shell station southeast of town. My concern is being able to pull up to a pump, and able to exit. Boat is 10.4 wide, trailer ~48 ft long... Have to also get AZ wide load permit unless I go through CA. CA permits a real pain...
Yeah, can't believe how hard the water there is.

Doug, I convince brad to do sea level tuning at Folsom Lake. Will let you know date. Both motors out of boat, ordering pistons for both tomorrow.

Anyone have comments about original thread? Old timer offshore racer incorrect?

The high octane race fuel will more than likely foul the spark plugs at idle and the engine will make less HP.
In my younger days, I used to do some drag racing with a street rod designed to run on pump fuel, I was low on fuel and all they had at the track was 110 octane race fuel. I mixed in about 5 gallons with the 5 gallons that was left in the tank. My 1/4 mile times went down about .4 sec and the engine idled terrible.

Interesting comment. I am rebuilding two 900 HP motors due to detonation damage. Very expensive... Don't want to have to do it again.. Keep the comments coming guys!

Rick

in the the desert..if you cant find a marine place, try an offroad/atv place. May be cheaper in the long run to buy drums too. Quick google...from the piks, no problem with your trailer either

http://www.campbellcove1stop.com/lak...s-propane.html

thats a nice set up for boats

Wide load permit for a year in California costs $90 and are over the counter. Check the laws as for the requirements of the tow vehicle and tow times. We only rent the storage units and stay at the Hampton Inn. Fuel is never a problem and why would you want to run Race fuel for 900 h.p.? There are much wider and longer boats than ours. Relax. Doug

Retune them to work on pump gas, at the elevation you will be running.

My guess is it detonated from too much boost, too much timing, or not enough fuel.

This rebuild costing in excess of $30K because of low octane...Don't want to use 91 Octane.. 103 would be fine, or something like that without ethanol in it. I believe in Boy Scout motto: "Be Prepared"! Just need address of where I can get in and out and get a reasonable octane fuel, and thanks to previous post I may have found it!

CA wanted me to have pace car in front, full wide load procedures - just to go from Tahoe to Sacramento on I 50. At that time 80 was closed to wide loads due to construction. I have one year NV permit -$90.

Plan on going through Vegas, need to check if they will let me through stateline at Hoover. I remember leaving Hoover south being a little tight. Plus, got full inspection at border.

Otherwise, will look into going 395 through CA

Clogged injectors AND bad fuel-2 yrs old...

Actually, we are tuning it for two elevations. 6250 ft and sea level with a flick of a switch and blower pulley change. This way I don't have to buy another set of expensive props and won't run rich at altitude. Plus, will have O2 sensors installed in exhaust with complete EFI update.

Sounds like a good plan!

Hope so! Motor was WAY overdue for refreshing. I thought these motors lasted hundreds of hours. Came to find out top end should be done every 50 hrs and bottom end every 100 hrs. Do I have that right? Same refreshing schedule as Merc 1075's... I will check this to make sure I got it right.