Is there a significant difference in new vs. a 53 year old prop?

[Grandpa Mike]

I'm helping my son restore an old boat and motor. Though I have 40 years "under the hood" turning a wrench or two, when it comes to all things marine, I'm asking you guys, so...thanks.

The outboard is a 1960 40 hp Evinrude Lark ll. I hadn't considered it before but would a new, 2013 propeller have any significant advantage over a '60 model?

Assuming, that the old prop is in good shape would the expense of a new one be justified?

Specifically, my question is more about design, balance and efficiency. I fly R/C aircraft and prop selection and balance is critical. An air-screw made 50 years ago, even in great shape, couldn't begin to compare with a new "modern" one. Is this also true with marine props?

 

[steelespike]

Re: Is there a significant difference in new vs. a 53 year old prop?

There is no doubt that some of todays props are head and shoulders above a 1960 prop.
Solas props use a state of the art process called squeeze casting this makes a finer stronger more sophisticated prop.
I also think Turning Point also uses squeeze casting on their aluminum props.
These props produce close to stainless performance.

 

[GA_Boater]

Re: Is there a significant difference in new vs. a 53 year old prop?

Welcome aboard, Mike. I don't think your 53 year old Lark will show much difference unless the current prop is damaged. Not a 'Rude guy, but can you still get new props for the oldies?

 

[Grandpa Mike]

Re: Is there a significant difference in new vs. a 53 year old prop?

Thanks GA_Boater, I'm glad to be here! I have seen props here at iboat and they list a Non Thru Hub Exhaust, 1960 - 1976 as a 10 3/8 X 11 1/2, 3-blade.

I really don't think I need one but relating to model aircraft...some of my planes wouldn't even get off the ground with a 1960 prop. There's been a substantial increase in design and performance since then, at least in airscrews.

I was really wondering if there would be that much difference in marine props. The old one seems to be in great shape considering the years,...unlike me.

 

[emilsr]

Re: Is there a significant difference in new vs. a 53 year old prop?

Specifically, my question is more about design, balance and efficiency. I fly R/C aircraft and prop selection and balance is critical. An air-screw made 50 years ago, even in great shape, couldn't begin to compare with a new "modern" one. Is this also true with marine props?

View attachment 184982

Yes, absolutely. Remember when we had to pick through a bag of Top Flite wooden props to find one that was even close enough to be balanced? Now you can buy an APC composite prop that's pretty much dead on right out of the box.

It's the same for boat props.

 

[jestor68]

Re: Is there a significant difference in new vs. a 53 year old prop?

The Michigan props I have seen for those older motors appear to be copies of the original, so I doubt there would be any difference in performance.

 

[emilsr]

Re: Is there a significant difference in new vs. a 53 year old prop?

A couple more R/C analogies...

The higher the performance engine, the more difference you'll see between old and new technology.

Also, like with the planes, different props for different conditions. In the boats I always wind up with at least 2 props; a "power prop" for heavy loads/hot days, and a "speed prop" for light/cool conditions.

 

[Frank Acampora]

Re: Is there a significant difference in new vs. a 53 year old prop?



Yeah, but if you are restoring the boat and engine to period, go with a nice aftermarket prop in bronze like these. They look really pretty when polished and can be found on ebay if you look long and hard enough.

BTW: Remember whacking your knuckles with the prop and then squirting on Ambroid to stop the bleeding? What? Not old enough to remember Ambroid? How about doping a big wing in an enclosed area and getting high off the fumes? How about Hot Stuff and Pettit Hobbypoxy?

 

[emilsr]

Re: Is there a significant difference in new vs. a 53 year old prop?

I remember ambroid, and dope...but this was back in the control line days (my first radio was a Kraft 77). I also remember when CA glue came out; we didn't know the fumes were harmful until years later. It's a wonder I have any brain cells left.

A polished bronze prop would look sweet!

 

[Grandpa Mike]

Re: Is there a significant difference in new vs. a 53 year old prop?

Wow, I'm kind of overwhelmed...oh yeah I remember ambroid and butyl nitrate. Never had a Kraft radio but remember moving up to a narrow band FM. (First was a AM 4 ch.)

This isn't going to be a total restore. My son got the boat, motor and trailer from family. We are on a budget though. He knows that if it were up to the old guy...the 'rude' would be completely dismantled and in a tank soaking somewhere. No, just trying to use know-how, common-sense and temperance to get the old rig back on the water, safely.

Thanks guys, I appreciate the comments and remembering how little brain I have left...CA, doping a wing etc...

 

[Frank Acampora]

Re: Is there a significant difference in new vs. a 53 year old prop?

My first radio was that white thing--don't remember the brand, rudder only flip-flop. Had it in a Goldberg with a Veco 19.

I still have a 56 inch wigspan Skylark kit in the box and it can be set up with a single .29 or twin .19 engines. I bought it for a buck at a Gimbel's close-out sale way back in 63. Dang---That's 50 years. I aint that old, am I?

Someday, if I live long enough I may build it.

 

[GA_Boater]

Re: Is there a significant difference in new vs. a 53 year old prop?

Since this has gone completely off topic - Yeah, I sniffed the glue. In '64 as I was leaving the service I stopped at the base hobby shop and bought a 6 ft. wing span B-36 kit. I think it cost about $40. For years I would open the box and dream about getting her in the air. Alas, it was left in an attic during one of the moves. I still wish I had it.

Now I'll add something insanely modern to the thread.

 

[Grandpa Mike]

Re: Is there a significant difference in new vs. a 53 year old prop?

Oh no he di-int. I've spent thousands of hours at the field and NEVER seen the heli guys do anything more than hover unsteadily. Maybe a short lap of the field. Holy cow!

Oh, and Frank Acampora, since this thread is a complete bust now...lol...I just finished a 1937 Goldberg Zipper. I don't mean a short kit either. The box, the wood, the plans....all 1937 with a price tag on the original box of 8.00. Haven't flown it yet. I did replace the original (in the box) balsa spars with basswood. Thanks for the vid GA_Boater, that's insane!