Volvo prop shaft

[Ralph Savarese]

Can you put a propshaft from a 290 drive on a 270 to get a better prop selection

[mattyboy]

I believe you can put a merc splined shaft also for even more prop selections
do a search on prop shafts here

Matt

[MOP]

Ralph give All Island marine a call ask for Mike, he will put you in touch with their tech. They are very helpful and can and will get any V part you may want. I am pretty sure you can do it it.

Mikes number 516 764 3300 X112

<small>[ March 25, 2003, 08:29 PM: Message edited by: M.O.P. ]</small>

[BigGrizzly]

Ralph, I have don't bother. The difference is in the hub/spinner which is called the long or short hub. the long hub has a screw in the middle of the spinner to lock it down the short locks with a tab on the spline. Both shafts can use the same props just swap the hubs. I know I have both drives. the shafts don't interchange but all the gears do. My suggestion is wait a little while untill I get done testing and see if Solas will produce moder day good props.

<small>[ March 28, 2003, 12:51 AM: Message edited by: BigGrizzly ]</small>

[boatnut]

I'll share a little of my experience: After spending time and money on several Volvo driven boats ('67 18 2+3 Ford, '69 18 2+3 Ford, Magnum twin SBC, etc.), I am now convinced that the shape of the stock lower unit on the 270/280 style drives limit the boat speed to approx 57 MPH. This is regardless of boat or horsepower or prop or number of engines. It is almost like a speed limiter or governor that results from the prop effectively running out of solid water due to the shape of the lower unit in the range of 55 to 58 MPH. A modified lower unit (Volvo hand-made some "speedmaster" lower units for these drives but they are hard to find now) or a different drive is the only effective solution to get past this speed barrier. I have seen many attempts at homemade nose cone mods on these drives and have yet to see one worth the effort. If you are at 50 and trying to reach the barrier I described, then go for it.

[Ralph Savarese]

I beg to differ I have had my boat since 1966 and have always kept track of the speed either by gps timed runs or speedometer. I can tell you with out exagerating that I am pushing close to if not 65 mph running sbc aprox 300 plus hp.
I am turning a michigan repitched to a 14x3/4 x 23.5 with a cup 5000-5100

<small>[ March 29, 2003, 01:53 PM: Message edited by: Ralph Savarese ]</small>

[BigGrizzly]

BoatnutHydrodynamically the Volvo is the sane on an old 270 as a origional bravo and the 290 style is better than one. I also have a mid 60's 18. It is true that our 16 with a carbed 302 200+HP is only a high 50's boat. The biggest problem is the props that were available at the time. I am in the process of rectifing this problem. If you look in the post "Stanles steel props for old Volvos" you may understand what was available. You will also find that I did put on a nose cone from Hydromotive later but I only gained a little speed but better handling. I was over 63mph at the time. I also found the Holman&Moody exhaust held me up more than the lowerunit.

[boatnut]

Well guys I stand corrected. Thank You. I would have bet money that my conclusions were accurate based on a lot of personal experience, friends and even going to Donzi (when owned by the Chisholms) in the 70's and discussing this topic with them. However, your info on your two 18's show that now these drives are pushing boats into the mid 60's, wow. I better get with the program. Can I ask a few questions to be sure I understand correctly:
1) These are 270 lower units? Or 280?
2) One is stock and one has a modified nose cone?
3)The mounting (x dimen) is stock as done by Donzi?
4) Are you doing anything with trim other than the stock 3 pin locations?
5) Have you trued the bottoms of the boats or done anything in this area?
The props are more complicated than a simple question and it seems there are other threads to read on that as you suggest. I am curently using a Johnson (OJ, west coast prop that is sort of a modified Volvo design cast in bronze). And being I was in the range that I thought was the limit I didn't try to refine it farther.
I am not questioning your (good) news, I am just trying to understand how I missed the boat here.
I haven't tried any of this experimenting in the last 20 years which sounds like a long time but I didn't think anything changed in the 270/280 arena during that time.

[Ralph Savarese]

1) volvo 270 springfield bullet nose cone
2) 3rd pin location
3) no bottom paint clean fresh polyurethane
4) stainless michigan modified LH 14 3/4 x23.5 +cupping
5) 1.61:1 ratio 5000+rpm
6) after following specs for building 350ci 350 hp aprox 65 mph
7) Major Torque Steer

[knee deep]

Where can i get the springfield bullet nose cone for my 270? And, while the boat is about ready to go back together will tabs help?

[BillG]

'66 2+3
Volvo 250 no nose cone
3rd hole plus 1/8 inch
bottom paint
Volvo ultra 14x24
1:61-5000 rpm
60 mph gps
351- 285hp
no torque steer. Johnson prop I had before had tremendous torque steer problem.

Bill G

<small>[ March 31, 2003, 07:55 AM: Message edited by: BillG ]</small>

[BigGrizzly]

I did my testing to start with with the old 270 style and no cone and a Michican wheel aluminum prop to get to 60 pin actually in the middle. I had made a movable pim like an outboard so I could change easily. Third hole was only worth it on calm days and slower in rough-remember I have a Corsican. Than I modified thoes props forever not any real improvement. Than I got a Rom Hill prop(FROM Hill befor the buyout) this was the most improvement than I put on a Hydromotive nose cone- a glue on not a weld on. Handling improved at high speed as well as low speed hunting. Then I put on a 290 trim with the 270 nose coned bottom. I won't say speed increased but setup for all water conditions was great. Than I put on the 280/290 lower - no nose cone, no change in speed but handled a little better still. Than I put a Hydromotive nose cone on it, it handled better still with less cavitation than ever before but no top speed improvment. During these changes no engine mods were done because the engine is where I want it at this point. Also remember at the point of the Chisholms era motors were very mild compared to today. In thoes days. 70 mph was a dream for all but the mighty few. The old H&M 351 Clevland was only at 250 hp on a real dyno with car hedders-hardly neck snapping. I stopped messing with my boat in 1997 because of props or should I say lack there of. Oh yea I did try the Volvo 4 blade Ultra prop last year, nice prop but no speed increase. I would rank it with the Hill prop. Soon I will be testing a modern prop and maybe we will raise the envolope even higher.

Woodsey, tabs do help on porpoiseing thoes bad days or to level the load. Just don't install too low so they drag.

<small>[ April 01, 2003, 01:15 AM: Message edited by: BigGrizzly ]</small>