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Counter vs. standard rotation 1990 454

C

contender31

Regular Contributor
I have a 1990 Tiara 33 Open with twin counter rotating 454 carburated 350 hp crusaders with velvet drive transmissions. I am considering replacing the engines and have a line on 2 standard rotating 454 fuel injected engines to replace the ones I have. The main reason for considering the switch is primarily cost.

I have a couple of questions

1. What is involved in changing to standard rotation?
2. How different will the boat perform?
3. The guy I am considering buying them from isn't sure if they are standard or counter- what is the best way to establish the rotation with the engines already out?
4. What is involved in changing to fuel injection considering the new engines come complete as bobtails?

Thanks in advance for your input
 
Re: Counter vs. standard rotation

1) assuming the "new" engine is the basis of this one, you'll need a different gear. Most go with the newer "full power reverse" types. These are usually provided with the 'offset' output shaft so you may want to consider them in pairs. Another option would be to get another prop (opposite rotation) but then you'd loose the benefits of counter rotating wheels.

2) If the gear is swapped to maintain counter rotating wheels, probably the same unless the engines are rated significantly different from what you have.

3) If they are crusaders, check the serial numbers - the 'handedness' is provided there. If they are sitting on a frame, you can bump the starter and what which way they spin but you'll need a battery, cables, and a remote starter. You can also remove the starter and look at the bevels on the ring gear.

4) the FI specific part of the swap would depend on which model is going in and its fuel system. Worst case, you may have to reroute some of the fuel supply lines and add a return to the tank(s). Mmost of the newer units have a "returnless" fuel system which requires NO return at the tank.
 
Re: Counter vs. standard rotation

The owner tells me that the firing order is the same on both engines, does that mean they are standard and not counter rotation?
 
Re: Counter vs. standard rotation

I am going to try and make this a simple question

My current engines counter rotate so my velvet drives rotate the direction of the engine. If I install 2 standard engines how do I convert the current transmission so that it is compatable with the new standard rotating engine? I understand that borg warner has a fix for this scenario - is this right? and if so what is the fix?
 
Re: Counter vs. standard rotation

one can go in w/ no change to the gear.

You will need find an old CR2 unit (ain't been made in a while) with the correct ratio or get a new 5000 series gear for the other side.
 
Re: Counter vs. standard rotation

Many of these boats, using same rotation engines, use either the 1.88 or 1.91 reductions (reversing), and the other engine gets the 2.1 (non-reversing) ratio. You haven't mentioned it, but you may already have the 2.1's installed.
 
Thanks for the input - here are the transmission models and gear ratio
Starboard - 10-18-106/ 1.88:1 --- port - 10-18-006/ 1.91:1

Hope this helps
 
I mentioned earlier that my engines rotated different directions but may have prematurely given you the wrong info, if my belts etc turn the same direction on the front of the engines and one of the transmissions turns opposite, is my presumption correct that one of the transmissions is already set to spin an opposite direction? If that is the case then will the new engines work with these transmissions?

Sorry for the confusion
 
You're all set. Your motors are the "normal" types which is now standard of the industry for new boats. The prop direction is determined inside the trans.

Jeff
 
contender31 said:
My current engines counter rotate ..............
Click to expand...
Would this be better said if you were to describe your current engines as one being Standard (LH rotation) and one being Reverse (RH rotation)?
LH normally being Port..... RH normally being Stbd.

contender31 said:
............. so my velvet drives rotate the direction of the engine. If I install 2 standard engines how do I convert the current transmission so that it is compatable with the new standard rotating engine? I understand that borg warner has a fix for this scenario - is this right? and if so what is the fix?
Click to expand...

Depending on the Velvet Drive transmissions, they may not be reversible for FWD thrust.
IOW, you may need to stay with the same rotation engines as what you now have.
I don't know the answer to this....... Some may be reverse capable.... some may NOT be.
You may want to speak with a Borg Warner expert.

BTW.... I'm not sure why you would have two different ratio transmissions.

***************

To determine the Rotation of an engine, they will always be viewed from the Flywheel Side.
LH (ccw) is Standard (single engine boat, car/truck)!
RH (cw) is Reverse or Counter Rotation!

You have a choice to help determine the rotation:
Bump the starter motor, and see which direction these engines turn.
or.......
Look at the distributor cap, find #1 spark plug lead......, see which cylinder follows this in a Clock-Wise direction
(your distributors will both still Rotate Standard due to the GM oil pump direction)

all small block and big block firing patterns are 1,8,4,3,6,5,7,2 for chevy
Read more: http://wiki.answers.com/Q/Distributor_firing_order_for_big_block_chevy#ixzz17A0kPBgC​


The distributor will rotate CW in either engine...... but the firing order changes.
distributor.png

In the LH Standard Rotation engine, note that # 8 follows # 1.
In the RH Counter Rotating engine, # 2 will follow # 1.
(both in the same clock-wise distributor direction only)

This should be an easy way to determine which hand each current engine is now!


.
 
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contender31 said:
Thanks for the input - here are the transmission models and gear ratio
Starboard - 10-18-106/ 1.88:1 --- port - 10-18-006/ 1.91:1

Hope this helps
Click to expand...

Are these the transmissions currently in your boat? This appears to be an odd arrangement. The 1.88 is the old version of the 1.91. Both will change the engine rotation direction. And, like all VD's, they can be configured to run either LH or RH input. If your going to go with two engines, both LH, then you should be headed to the 1.91 on the starboard, and the 2.1 on the port.

I think that by the time your boat was made, 1990, that 1.88 ratio was long out of production.
 
He's got an old CR version.

Starboard - 10-18-106/ 1.88:1 --- port - 10-18-006/ 1.91:1
Click to expand...

The starboard gear is 'normal'. With the 'normal' 1.88 gears, the output is reversed. So with a LH engine, the prop should be a RH wheel. The port is the CR version; opposite from the -106 gear, this should behave like a 'regular' reduction gear (input rotation = output rotation). So a LH engine driving this gear on the port would swing a LH wheel.

Like Jeff said, he's good to go as far as the gear goes.
 
Dave and Mark, any idea as to why the two ratios? Just curious.
Also, Mark..... why swing a Port side prop, in a RH direction?
 
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I'd guess you'd be hard pressed to notice much difference between a 1.88 and a 1.91 gears, especially with an "out of the box" wheel. I'd suspect the gear was changed somewhere in the 20 years the hull's been around or that's "what was available" when it was assembled.

If the port engine is LH and it has a CR 1.91 gear behind it, its shaft spins LH so I don't understand the RH direction query. If it was a normal 1.91 gear, the shaft would go RH and that would require the "wrong" wheel.
 
makomark said:
  1. I'd guess you'd be hard pressed to notice much difference between a 1.88 and a 1.91 gears, especially with an "out of the box" wheel. I'd suspect the gear was changed somewhere in the 20 years the hull's been around or that's "what was available" when it was assembled.
  2. If the port engine is LH and it has a CR 1.91 gear behind it, its shaft spins LH so I don't understand the RH direction query. If it was a normal 1.91 gear, the shaft would go RH and that would require the "wrong" wheel.
Click to expand...
  1. I would agree! So, this is a result of a change at some point.... not by design then!?
  2. Well, that's what I thought! Port = LH prop! Yes/No?
 
Sorry had a day trip and just got back to read your threads. When I bought the boat back in April I was told that one of the transmissions had been recently rebuilt so thats maybe why the change in gear ratio. The mechanical records are poor on the rebuild but the only parts that he writes are 72C Clutch fwd rev if that helps??
 
Ok i got tot the boat and here is what I have - both engines turn clockwise, starboard transmission turns clockwise, port turns counter clockwise. So based on this actual i guess this means that the new engines which are both standard will work without any modifications to the transmission correct? now the last question -- my current engines are carburated, the new ones are fuel injected -- they are complete bobtails w/o the transmissons so is there anything that I should be aware of when preparing for the switch and how much more fuel efficent will they be with my boat - 33 tiara open - fyi these engines are the same hp as my current engines but have 800 hrs less on them. they appear to have been well maintained, they were taken out of a 36 tiara open that was converted to diesel due to fuel economy.

thanks in advance for your input
 
FYI not sure if this means anything but the older stye 1.88 is quite a bit noisier than the 1.91 tranny. It gives off a low tone growl when in gear fwd or reverse - is that normal? It's not a grinding noise just a low growl - the tranny works fine at any speed. The 1.91 seems to be very quite and silky while in gear. If I am making the switch of the engines would it be a good idea to change out the gears to 191 to match both? Is there any true benefit to switching other than the noise?

Thanks for your continued input
 
Two things:

Noise is not a good sign. It indicates that the gear set may need bearing replacement, and a fresh pattern set.
Failing bearings will not heal..... they will continue to get worse!
They will/may eventually destroy the gear set $$$$$$$$$!

It would be best, IMO, if both sides used the same ratio..... but as said, these two ratios are very close to one another.
For me...... I'd want them to be the same.

.
 
Ok I am gettng close - I have a 1990 tiara 33 open with twin 1990 454 350 hp carburated engines with velvet drive counter rotating transmissions- 1 port is model # 10-18-006/1.91:1 , starboard is 10-18-106/1.88:1. I want to convert my engines to 454 350 hp standard rotating fuel injected engines.
*
I want to recap and post questions that I think have yet to be answered
*
1. It appears that the transmissions will work with the new engines.
2. There appears to be some confusion with the gearing - one tranny has a 1.88 and the other a 1.91. The last post shows the 1.91 being the older of the 2. Someone recommended correcting the gears when I convert the engines but a little unclear as to why. I mentioned that the starboard tranny had a low tone growl when in gear but seem to work fine under load at any speed.
*
Questions unanswered
*
1. Is there any possible issues converting from carburated to fuel injected engines? considering the new fuel injected engines come complete as bobtails - see pictures below.
2. Will the new engines mount to the old transmissions without any modifications?
3. Will the new engine motor mounts align with the old setup? Just asking if anyone has ever converted a fuel injected 454 from a older 454?
4. What can I expect as far as peformance and fuel economy?
*
Thanks for your continued help
 
Obviously, you have Borg Warner F/C's on both engines.
Borg Warner is Borg Warner all day long. Should be NO issues there.

FI will give you much better start-ups, some say better fuel economy...... I suggest; Don't expect much.
If budget allows, it's certainly a good call.


Is it possible for you to install crankshaft pumps instead of the belt driven sea water pumps?
It sure makes routine servicing much easier.
Many will forgo impeller inspection due to the task involved with the belt driven units.
.
 
Yes sir I am i agreement with you fuel injection is the way to go. I will research the pump situation. I know I have changed a few impellers on mine and it is a brutal job for both belts and impellers. Main reason is safety, never felt comfortable with carbs, always thought of fire and potential explosion issues. My engines have 1400 hrs on them and getting tired and not keen about piece mealing old technology as when it starts it never ends at this age. You fix one thing then something else happens.

Thanks
 
My documents show both the 1.88 and the 1.91 reverse engine direction, so, I'm not sure what to make of all this. Beyond that, FI is a good thing, is it throttle body or MPI? Also, the later 454 blocks migrated from the Gen IV to the V and VI. THere is a bunch of chatter on how "bad" the Gen V's are, mostly related to the lack of valve adjustment. Although the V did go to a one piece main oil seal, regarded as a good thing. I think it is a mixed bag, if you get 10% or better mileage improvement, then that is very good.
 
10 % wouldnt be too bad on a 290 gallon tank, means perhaps 60 gallons to the Bahamas instead of 68 from Palm beach. Bahamas are 60 miles fyi
 
curious how much labor time do you guys think it should take a qualified certiified marine mechanic to takeout and install a 454 in a 33 tiara open with a soft top? presuming the hatch has been removed in advance and he has a crane?
 
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