bertram31.com

Abandoned ideal of selling my 31 and going forward with repower. I am speaking w/ some Cummins dealers and have a few questions that I think you guys can easily answer.

1. One distributor says the 6BT factory recon is 210 HP; another says 220 HP. They are the same engine as far as I can see from the specs they sent me???? Which is correct.

2. What is the exact model and specs for the ZF transmission I will need? One says a ZF220 and another says ZF63a. Also, what down angle is it 7 or 10 degrees?

3. Is the best ratio 1.5:1?

4. What is the propeller specs and size I will need? Does anyone know a good source?

5. What is the shaft diameter I should use. I currently have 1.25" w/ my original Chrysler 454s.

6. I want new struts also. Does anyone have specs, size, model, vendor for these?

7. What do you all recommend for packing shafts?

I think Walter has the 210 Cummins setup and know he is very happy with it.

Thanks in advance for any help. I know these may be dumb questions but I want to get it right. Just trying to iron out the details.

Joe Z

The engines I bought were 210's, some people have been recently calling them 220's. I don't think anything has changed except the numbers. They are bulletproof engines on which the higher HP 6bt series are built. Mine are coupled with twin discs and the gear ratio is 1.5:1. Are you sure your shafts are 1.25"? I ask because mine had Chryslers before my repower with 1 3/8" shafts which have worked fine for me. I am presently turning 20X20 slightly cupped props and am a bit underpropped as I can exceed my wot of 2650 by about 75 rpm. With those props my cruise with an older heavy hulled, heavy teak decked Sportsfisherman is 21-22 kts @ 2400 rpm. Very simple engine to maintain. 14 qt oil change with a spin on filter. A Racor fuel filter and a secondary spin on one. That's it! I'd suggest an oil pan fitting with a hose and cap bought up from underneath to the inside side of the engine for easy oil changes. Expect fuel consumption of about 8 gph at cruise. Hope this helps.

Joe ...

If you are still looking at Cummins recons drop me a line.. my local guy usually has good prices, and he can do installations as well.

IRGuy@aol.com

Frank B

Thanks a bunch Walter. You have given me great info in past. Yes, my shafts are 1.25". Pete Fallon did a survey on it and said they were 1.25". However, I am going to measure myself to be sure.

Do you have the exact model #s/specs for your gears. I'm confused about this because one dealer is saying I need ZF220 and other says ZF63a???? Not sure what the difference is???

Also, what is the size of your exhaust? I currently have 3" but I think I will need 4", right???

Thanks a bunch. Joe Z

your questions would take a book to answer and GOD forbid i leave something out. once opon a time in the late eighties cummins use nippendenso fuel pump now they are bosch 7100 the hp was change to 220 hp from that time . next question (you only get two tonight) zf took over hurst gears the zf63a was theres. the irm 220a is stronger but more then you need for the 220hp zf63a is fine.

Mine are 1990's and I know my injector pump is a Bosch. One of the rationales for buying the Cummins was that back then Chrysler would not honor their warrantees on new Chryslers unless you increased the size of your exhausts. When we calculated the cost of the change, plus the cost of the engines plus the cost of modifying my engine boxes (they changed the exhaust manifolds from teardrop ti square, making them wider) I could just as well have diesels that sip versus gassers that slurp, and the 210 would accept the size of the original Chrysler exhausts. Now they're straight pipes with no mufflers, but they've served me well since then. I have to assume that at that size, mufflers might cause a degree of backpressure and straight pipes don't. At that time, it was really a matter of money and turned out to be the best decision I've made in quite a while. I would have had 2 sets of gassers by this time, to say nothing about my fuel bills. I'll check on which Twin Discs I have this weekend.

Joe,
When I re-powered Dreamsicle I came across a pair of 1990 6BTA 300's (Nippon pumps) with shafts and exhausts and gauges from another 31. Perfect fit. They are the same as the 210's you are installing with the exception of aftercoolers and some boost, but as far as installation, the same.
I had 1 3/8" shafts originally which are still in the garage if you are interested. The shafts with the package were 1 1/2". Cut the brass sleeve of the new cutlass bearings and they slid right into the struts. Unless you just "want" new struts (or need) why change? I think Buck Algonquin has the struts.
I have 220a's, 1.5:1. 10% down angle.
I used the packing glands that came with the shafts and replaced the packing with teflon type which are dry when sitting but drip enough underway to get the job done.
Also when doing the installation I got some great pictures of the engine towers which may help your fabricator.
Most of my help during this trial and tribulation came from Walter and Uncle Vic. Vic's pictures of his towers and their installation were a manual for mine.
Lots' of good help here.
As Walter has eluded, when you are done and in the water you will be thrilled with the outcome.
Keep us posted and let me know if I may help.

If your going to use a local Cummins dealer, let me know who your talkin to and I'll let you know who to stay away from.

Buy the engines and do it yourself is another option.

I have a pair of re-mans bought in 2007 for the Tiara and they say 220on the paper work but the dyno sheet came along with them and they are 210hp. I am using rebuilt gears Twin Disc 502 1.54:1 is the ratio you need for these engines since they only spin 2600rpm. I know the rage is those dripless packing glands but i went with the type that has two studs instead for simplicity and problem free future. I am not too keen on the little water hose that has to feed the dripless system and after several years some do need attention. Good luck Troy.
P.S. I dont think you could have picked a better engine for that boat. it has no aftercooler to maintain and is a bulletproof low horse version. I will sacrifice speed for longivity every time

Whalter,

Your set up with the 210's + the twin disc will run forever. 21-22kts covers 95% of the days offshore. Nice, simple. bullet proof combination. Those sould be 18,000 - 22,000hr engines.

Nice.