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Re: How much power can I make from 260 CI

Posted: Wed Nov 08, 2017 10:20 am
by jet1
Charge cooler is really easy with a huge water pump already in the back of the boat vs methanol in a boat with all kinds of water around. Hopefully av gas will be enough. going to q16 is way pricey with the amount of fuel we go through.

Re: How much power can I make from 260 CI

Posted: Sun Nov 12, 2017 6:40 am
by kimosabi
jet1 wrote:
Wed Nov 08, 2017 10:20 am
Charge cooler is really easy with a huge water pump already in the back of the boat vs methanol in a boat with all kinds of water around. Hopefully av gas will be enough. going to q16 is way pricey with the amount of fuel we go through.
Yeah I was thinking weight that's all. You'll easily save 25lb or more by not bolting a chargecooler in the boat. How much you pay for avgas, I assume 100LL, compared to E85. If E85 is available to you.

Re: How much power can I make from 260 CI

Posted: Sun Nov 12, 2017 9:18 am
by peejay
hoffman900 wrote:
Thu Nov 02, 2017 7:30 am
Absolutely. I like the destroked Mod motor. As you said, the heads and intake would be the stock castings.
Why not debored? Sleeve a Mark VIII block down with some thickwall sleeves, gain better ring seal with your lower displacement?

Re: How much power can I make from 260 CI

Posted: Tue Nov 14, 2017 12:25 pm
by jet1
kimosabi wrote:
Sun Nov 12, 2017 6:40 am
jet1 wrote:
Wed Nov 08, 2017 10:20 am
Charge cooler is really easy with a huge water pump already in the back of the boat vs methanol in a boat with all kinds of water around. Hopefully av gas will be enough. going to q16 is way pricey with the amount of fuel we go through.
Yeah I was thinking weight that's all. You'll easily save 25lb or more by not bolting a chargecooler in the boat. How much you pay for avgas, I assume 100LL, compared to E85. If E85 is available to you.
E85 is not available around here at the present time. Av 100ll runs me about $1.75 litre.

Re: How much power can I make from 260 CI

Posted: Tue Nov 14, 2017 12:29 pm
by jet1
peejay wrote:
Sun Nov 12, 2017 9:18 am
hoffman900 wrote:
Thu Nov 02, 2017 7:30 am
Absolutely. I like the destroked Mod motor. As you said, the heads and intake would be the stock castings.
Why not debored? Sleeve a Mark VIII block down with some thickwall sleeves, gain better ring seal with your lower displacement?
Thats about were I am at only with an LS motor. Use some Darton dry sleeves and bring the bore down on an LS3.

Re: How much power can I make from 260 CI

Posted: Tue Nov 14, 2017 1:37 pm
by englertracing
peejay wrote:
Sun Nov 12, 2017 9:18 am
hoffman900 wrote:
Thu Nov 02, 2017 7:30 am
Absolutely. I like the destroked Mod motor. As you said, the heads and intake would be the stock castings.
Why not debored? Sleeve a Mark VIII block down with some thickwall sleeves, gain better ring seal with your lower displacement?
Because big bore short stroke....

Re: How much power can I make from 260 CI

Posted: Tue Nov 14, 2017 7:24 pm
by peejay
But boost. RPM spec is only 7500, no need to play bore/stroke games at speeds that low. Block integrity would seem to me to be more important.

Plus, I keep hearing that thin cylinders cause thermal issues from blowby, so having nice thick cylinder walls would be a boon to keeping temperatures properly controlled.

Re: How much power can I make from 260 CI

Posted: Wed Nov 15, 2017 8:23 am
by ptuomov
peejay wrote:
Tue Nov 14, 2017 7:24 pm
But boost. RPM spec is only 7500, no need to play bore/stroke games at speeds that low. Block integrity would seem to me to be more important. Plus, I keep hearing that thin cylinders cause thermal issues from blowby, so having nice thick cylinder walls would be a boon to keeping temperatures properly controlled.
The modular Ford with its DOHC valvetrain would run at 7500 rpm with no issues for the next forever.

If the block can be sleeved reliably to be smaller bore, in a turbo motor small bore will work out great. One can give more boost at the same geometric compression ratio because the combustion chamber is more compact. 86.2mm bore and custom pistons on a four-valve modular Ford with completely standard valvetrain would probably fit and run at 7500 rpm with now issue, but mod Ford experts should chime in. Would the combustion chambers need to be welded for a good chamber shape, or does the stock chamber look good with 2mm shift in the bore wall inwards? Factory crankshaft, too, would that work? From the turbo perspective, one could boost the sweet bejezus out of it. That's close to Mitsubishi Evo bores and those engines appear to burn very well.