53 YF Series I vs. Series II

[tgotch]

Looking at the models brochure pages. Noticed Series I shows produced from 1977-81. Series II from 1987-90. Any major changes from series I to II?

 

[SKYCHENEY]

Exact same boat except the series I has 8v71ti's and the Series 2 has 6v92Ta's

 

[oldawg]

Slightly different flybridge as well I believe.

 

[SKYCHENEY]

Slightly different flybridge as well I believe.

Same flybridge

 

[Captain Cigar]

Exact same boat except the series I has 8v71ti's and the Series 2 has 6v92Ta's

Which engine is better?

 

[Captain Ralph]

Which engine is better?

I may catch some stuff on this;
IMO The 8V71 is better.

 

[SEVEN]

Agreed 871

 

[Captain Cigar]

I may catch some stuff on this;
IMO The 8V71 is better.

I know pretty much nothing about diesels. What are the differences between the 2 and why do you like the 8471 over the other one?

 

[Captain Ralph]

I know pretty much nothing about diesels. What are the differences between the 2 and why do you like the 8471 over the other one?

For Starters;

The 92 use wet cylinder liners. The 71s are dry. The Achilles Heel of the 92s are these wet liners and their O rings.

I consider the 92s a lil more performance oriented. IMO, at low speeds head temperatures are lower and wet with un-burned fuel. Loaded, the 92 may offer a micro more economy but I can not afford to run loaded to find this economy.

71s are more forgiving than 92s. Get a 71 a lil warm and no big deal, a 92 usually requires at least new liners.

IMO, 71s last longer.

Most 71 parts are un-changed since the 1940s. 92s were born mid 1970s.

 

[SKYCHENEY]

I had over 5000 hours on my 6v92's when I repowered. They still ran fine. I sold them to a yard nearby and they put them in another boat. So.........

YMMV but I was very happy with the life out of my 6v92s

 

[Fanfare]

I replaced my original 8V-71na engines with 6V-92TA about 30 years ago on Jack Hargrave's advice. Picked up 200 hp per side at 550 hp. Mine have been virtually flawless. They don't leak oil and I went with the mechanical version instead of the then brand new DDEC option which, in hindsight, turned out to be wise. Other than one ten minute full throttle burst per season I never run above 2000 rpm. Changes in instrumentation make it difficult to come up with exact hours but I estimate about 3,500 hours. I contemplate the present "good" original O-rings on the cylinders with a possible rebuild with new, but perhaps questionable modern rubber O-rings. I currently lean to the "if it ain't broke" philosophy. Guess I will see. Excellent engines in my experience.