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Mercruiser specs and info 260V8 HP or displacement

R

rmurray

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"Is there a place where I can

"Is there a place where I can look up the specs and ratings on older Mercruisers? I am in the market for a used boat and I'd like to be able to look up information on each motor. For example, the latest boat I found has a Mercruiser 260/V8. I believe its a 350 ci with a HP rating of 260 (so I guess some motors show displacement and others show HP rating?). It has an aluminum 19 pitch prop and drives a 21' Eliminator no more than 50 MPH. Seems slow. Is it the motor or the prop? Its mounted to an Alpha One. The seller claims I can get more speed with a different prop. ??? Thanks for any help!!"
 
Your guess is correct about th

Your guess is correct about the 260 being a 260hp 5.7L SBC. 50mph doesn't sound too far off. Changing the prop may get you more top end at the expense of the bottom end. Don't know of a listing off all the merc engines by model number. I usually research when I'm looking to find what a particular motor is. Then the S/N is very helpful.
 
"50mph out of a 260hp, 350cid,

"50mph out of a 260hp, 350cid, 5.7l, in a 21' boat,+ an Alpha drive is doing Pretty Good.......

I Really Doubt there's Any more MPH to be Found.....

Just How Fast do you Expect to Go,..??..
Or,...
How Fast do you Want to Go,..??...."
 
I would have thought with a 35

I would have thought with a 350 that 60 MPH would be more likely. Thanks for the info.

I might run the exhaust through the transom. Will that increase HP any?
 
"The speed will be determined

"The speed will be determined by the hull's efficiency. If it's sleek and streamlined, it should go fast and if it has a step in the hull, it'll go faster. If it's round and bulbous, the wetted surface will be greater and will take more to get it going, and to go fast."
 
"[quote]I might run the exhaus

"
I might run the exhaust through the transom. Will that increase HP any?
Click to expand...

Nope,.... Not Really,..... It'll just Sound like it's More Powerful......"
 
"I ended up buying this one fo

"I ended up buying this one for under $7500. This boat appears to have been very well maintained (always garaged, original paperwork from factory, etc). We checked it out thoroughly. I appreciate all the info that everyone posted. I'll probably do a few upgrades (thru-exhaust, headers-maybe?, stereo, etc). Similar boats are going for $10k. I had two boat owners/mechanics inspect it for me! Can't wait to get it out on the water...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=012&sspagename=STRK% 3AMEWA%3AIT&viewitem=&item=220081451263&rd=1,1"
 
rmurray said:
"Is there a place where I can

"Is there a place where I can look up the specs and ratings on older Mercruisers? I am in the market for a used boat and I'd like to be able to look up information on each motor. For example, the latest boat I found has a Mercruiser 260/V8. I believe its a 350 ci with a HP rating of 260 (so I guess some motors show displacement and others show HP rating?). It has an aluminum 19 pitch prop and drives a 21' Eliminator no more than 50 MPH. Seems slow. Is it the motor or the prop? Its mounted to an Alpha One. The seller claims I can get more speed with a different prop. ??? Thanks for any help!!"
Click to expand...
 
Answered in your other thread but you'll find life to be much easier if you were to source a good used Mercruiser 7.4/454 big block. Going from Chevy to Ford involves some changes and the parts that you need may not be available.
 
A major factor in how fast a given boat can go is the deadrise angle. This is the angle of the hull at the transom. Flat bottom boats go fastest, Deep Vs slowest. You will get beat up in rough water in a flat bottom boat,, and have a comfortable smooth ride in rough water in a deep V.... Name your poison. Also going very fast in a short boat can lead to instability... note how long the "go fast" boats are. Also running continupusly ar wide open throttle reduces engine life.... and burns lots of gas.
 
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Going to any big block or high power or torque then specified by Merc is not reccomended for Alpha drives.

Big blocks typically have a bit to much torque and will cause upper gear failire.

Both Merc With Chevy based engines and OMC with Ford based engines, went to Bravo and King Cobra drives for big blocks for this reason.

Keep that in mind!
 
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