Fuel oil mix ?

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03-03-2018, 01:19 AM
91eagle

Fuel oil mix ?

Wanted to get everybody's opinion on a few things....
I just noticed the otherday that the Shell station down the street from the boat ramp I have always used sales the higher octane "race gas" or whatever it's called I think it's 110 octane I'll check and make sure tomorrow..... what's the benefits to switching to the higher octane is it worth the added cost and do you switch up the premix or mix it the same as you would 93...... and just add to the conversation what oil do you guys use and what's the mix ratio in the 2.4 and 2.5 Mercs
03-03-2018, 07:27 AM
patchesII

There is no benefit to using a higher octane fuel than is required by your compression ratio and timing. In fact, it will hurt power.
03-06-2018, 11:21 PM
91eagle

Quote:

Originally Posted by patchesII

There is no benefit to using a higher octane fuel than is required by your compression ratio and timing. In fact, it will hurt power.

.... I'm having a motor put together now that somebody had did a lot of machine work and the exhaust chamber the heads were land and sea and I sold them once I get it together of course I'll do a compression test but... what I'm asking is What compression would you recommend using the higher octane... I don't want to use pump gas on something that would run better with the 110 or vice versa

Thanks
03-07-2018, 12:41 AM
powerabout

I would find out exactly what that fuel is first.
03-07-2018, 08:14 AM
Hot Shot Merc

93 oct is good for up to 145-150 lbs compression. If your not planning to drag race there really is no reason to have compression any higher than around 145-150.
03-07-2018, 10:55 PM
Krazymaan

When i want to go F with the deep pocket boys in their big macho bass boats and the ones in there wake boats. You know the ones i am talking about. I will pop on some 26cc heads which bring the pressure up to 195 to 205psi's and run the gas station 110 octane fuel. I'll use the Yamaha 26p drag prop because you know they ain't gonna hit 100+. But keep the 32 in the truck just in case. This is my not so stock carbureted chrome sleeve oval port 2.4 Mod VP motor. If I am gonna wind it towards 9k I usually run the oil about 18:1 If I am not gonna wind it to the limit, about 24:1. I also use Pennzoil Premium Plus. If your exhausting through your lower unit, don't expect it to be clean, Its gonna be very black and oily. And another thought that nobody really talks about. This high compression setup for 20 gallons and fuel consumption only costs me $225 for 45 minutes of fun. But its well worth it. Hope that helps a bit.
03-08-2018, 09:22 PM
91eagle

Does anybody know what cc the factory heads are on a 260 ..2.5 ..... or the heads on a 2.4 Bridgeport were from the factory ?...... and one more question that popped in my head but I didn't want to start a whole nother thread for it what is the paint on the top of the blocks mean I've seen several different ones and they all had a little spot of color of paint sprayed on top of the block the last one I got is got like a orange color....
03-08-2018, 09:43 PM
91eagle

Attachment 401351
03-08-2018, 10:06 PM
Hot Shot Merc

Quote:

Originally Posted by 91eagle

Does anybody know what cc the factory heads are on a 260 ..2.5 ..... or the heads on a 2.4 Bridgeport were from the factory ?...... and one more question that popped in my head but I didn't want to start a whole nother thread for it what is the paint on the top of the blocks mean I've seen several different ones and they all had a little spot of color of paint sprayed on top of the block the last one I got is got like a orange color....

Typically they were 38 cc factory. 34 cc is safe for pump gas. 32 and your cutting it close and need thick gaskets. The diff color spray paint spots are assembly/inspection sign off markings I believe.
03-08-2018, 10:09 PM
KIRCHNER

absolutely and dont be told more is better.
03-08-2018, 10:18 PM
KIRCHNER

Quote:

Originally Posted by Krazymaan

When i want to go F with the deep pocket boys in their big macho bass boats and the ones in there wake boats. You know the ones i am talking about. I will pop on some 26cc heads which bring the pressure up to 195 to 205psi's and run the gas station 110 octane fuel. I'll use the Yamaha 26p drag prop because you know they ain't gonna hit 100+. But keep the 32 in the truck just in case. This is my not so stock carbureted chrome sleeve oval port 2.4 Mod VP motor. If I am gonna wind it towards 9k I usually run the oil about 18:1 If I am not gonna wind it to the limit, about 24:1. I also use Pennzoil Premium Plus. If your exhausting through your lower unit, don't expect it to be clean, Its gonna be very black and oily. And another thought that nobody really talks about. This high compression setup for 20 gallons and fuel consumption only costs me $225 for 45 minutes of fun. But its well worth it. Hope that helps a bit.

my drag race nova costs me 6$ for 6.3 sec of fun!