The general rule is 15-17 hp equals 1mph increase. Dragging a Volvo od that equation may be out the window.
The general rule is 15-17 hp equals 1mph increase. Dragging a Volvo od that equation may be out the window.
on a 7k budget you will get more bang for the buck in the chevy world than you will in the ford world and the chevy will bolt up to the 270
the chevy and volvo combo is pretty tough too
When the sky is grey,look out to sea.
When the waves are high and the light is dying,
well raise a glass and think of me...
When I'm home again,
boys, I'll be buying!
My Ride
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Matt has a good point. Lots of options for SBC and marine accessories are much more accessible.
You could pull your original 351 H/M and accessories and store for if you or someone else ever wanted to return the boat to it's original configuration.
I sold my 1975 18C in favor of a 1987 20 Minx because of the Merc drive had trim and was much more available. I do like the 18 Classic boat better and plan to go back to one at some point down the line.
Thank you, Patrick
1994 18' Classic 350Mag Alpha
Previously owned Donzis -
1996 22' Classic, 502Mag Bravo
1987 20' Minx, 350Mag Alpha
1975 18' Classic, 350Chevy Volvo 280
Thank you, Patrick
1994 18' Classic 350Mag Alpha
Previously owned Donzis -
1996 22' Classic, 502Mag Bravo
1987 20' Minx, 350Mag Alpha
1975 18' Classic, 350Chevy Volvo 280
Bigest hold back on a 351 ford are the cylinder heads they were designed for a 289 even though the older 351s had slightly larger valves and ports. Best to go with aftermarket heads as a start. First thought is do you want cast iron or aluminum? Fresh water or inclosed cooling system aluminum ok for fresh water. Cast iron for salt or aluminum with a coating thats about a 1000.00 option or inclosed cooling. Heads are about all there is holding back a ford compaired to a SBC.
Scars are tatoo's of the fearless
A mechanical resto would be all fuel lines and tank as well as new wiring then powertrain
When the sky is grey,look out to sea.
When the waves are high and the light is dying,
well raise a glass and think of me...
When I'm home again,
boys, I'll be buying!
My Ride
Come Join Us on The Queen Of American Lakes
Contact Us
www.lgdonziclassic.com
Take a look at this thread about some restoration work I did on an old 18 Barrel Back;
http://www.donzi.net/forums/showthre...Barrel-Back-18
If you have any questions, don't hesitate to ask.
George Carter
Central Florida
gcarter763@aol.com
http://kineticocentralfl.com/
“If you have to argue your science by using fraud, your science is not valid"
Professor Ian Plimer, Adilaide and Melbourne Universities
Im in the completion phase of two 418cid 351w. Ill keep you posted. Forged pistons, cast Scat crank, H beam rods forged. Roughly $1500 balanced with Harmonic Balancer...each plus machine work.
427 Windsors were much more (2k+) due to only being available with forged crank. This was little different in price from rebuilding my reciprocating stuff with new pistons.
I think we're at 10 to 1 compression. Ported and big valve 1969 4bbl heads. Offenhauser 360s, Holley 750s. Comp Cams.
24' Nova Sprint 1971
You are what you drive!
Fwiw...just noticed your budget. Mine is 10k for the two engines. Long blocks built by machine shop. New cam and kits (one custom ccw). 700 worth of Mallorys. A new 750 Holley. 3 blocks pyrchased in addition to 2 i had. The plight of dealing with a bunch of non running parts and no backstory.
Machining and modify standard 69/70 4bbl head to match other big Chebby valves and matched porting of other 3 heads (as i had 1 cracked head). Same with 1 Offenhouser 360 intake.
I was told NOT to buy the $700 per set aluminum 351w Chinese complete heads off ebay. They would have saved a ton, but the machine shop has seen seats fail in 50 miles.
24' Nova Sprint 1971
You are what you drive!
If you want more speed, raise the drive up 2".
Jeff
" Just piercing the surface"
Dont know your heads air flow but well done there small for that many cubes. Also you will have a realy ruff time finding spark plugs in the proper heat range as most popular plug for a sbf with 18mm plugs have been discontinued. Either too hot or too cold is all thats left. Have been dealing with this for years on my 460 and 302.
Scars are tatoo's of the fearless
We discussed powertrain improvements needed to go 60+....what about structural? I'm thinking I'll add a few stringer braces throughout the entire hull. Seems to be a few short. I already have a large gray-colored "triangular" one in the bow (about 2' from tip - can be seen below)), but seems more are needed. It also seems to me more structure is needed to strengthen the cockpit-hull interface too. Suggestions/thoughts?
deck of hull donzi.JPG
usually once the main stringers are confirmed as solid and dry or replaced beefing it up is done with gussets that run port to starboard and some also use coring to make the hull solid higher speeds mean more torque and pounding stresses on the structure make sure you have weep holes and seal everything
When the sky is grey,look out to sea.
When the waves are high and the light is dying,
well raise a glass and think of me...
When I'm home again,
boys, I'll be buying!
My Ride
Come Join Us on The Queen Of American Lakes
Contact Us
www.lgdonziclassic.com
IMHO, tying the gussets into the hull sides will generally result in the bond in the hull sides will eventually break loose,
because the bottom and the sides move differently.
If you want stronger/stiffer hull sides, add another course of stitchmat to them.
If you want a 450 HP engine in an already stiff 18' boat, maybe add a couple of gussets that end a few inches from the hull sides.
If we were talking about 1000 HP, we'd be having a different discussion.
George Carter
Central Florida
gcarter763@aol.com
http://kineticocentralfl.com/
“If you have to argue your science by using fraud, your science is not valid"
Professor Ian Plimer, Adilaide and Melbourne Universities
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