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Rebuilt 305k RH engine - water in heads?

keithcatalina

New member
Hello all,

New to the group here and a new Chris Craft owner as of last fall. (1980 Catalina 28 with a gm 305k RH motor) To give some background to my issue, last fall when I winterized my engine I did not do it properly (was unaware of all the drain plugs in the block and risers.) This subsequently caused my block, the heads and one of the exhaust manifolds to crack over the long winter here in Buffalo.

So I have a couple (auto) mechanics that work for me. I sourced a used chevy small block with heads out of an '86 camaro. not realizing the existing engine was set up as RH we installed this engine using most of the original components from the old engine. Once we realized the goof we pulled the engine and installed the gear to gear cam set up to reverse the rotation. Get everything back together and while we got the engine to run decently there appeared to be two valves that were sticking, and despite adjusting them we couldn't get them to seat properly.

After adjusting the valves we had a hard time starting the engine and realized it hydrolocked. I replaced the intake manifold since we used the old one thinking it may be cracked internally but to no avail.

Is there any reason the RH rotation would cause this if we didn't do it correctly? Is there more to changing the rotation other than swapping the chain setup to the gear to gear setup and reversing the firing order? We didn't mess with any of the pumps or starter etc.

My last guess is that somehow both heads are internally cracked that we couldn't see when we had them off to replace the head gaskets. (or maybe the new head gaskets failed? seems unlikely...)

when it hydrolocks, we pull the plugs and we get clean water pouring out for what that may mean?

Any insight would be appreciated! We only have a few months of great boating here and my wife and I are at a loss for what to do.

Thanks!

Keith
 
You should employ the services of a Marine mechanic...... not an Automotive mechanic!

Secondly....… the piston wrist pin offset for the standard LH Engine will be incorrect for a reverse RH engine. If these are the GM F/D pistons, they can be pulled and reversed on the connecting rods.

Thirdly..... the std LH automotive camshaft will be incorrect in two ways.
....... The camshaft profile will be incorrect.
....... The lobe separation or “overlap duration“ will be incorrect for marine use.


Also...... the Camero cylinder head combustion chambers may be too small for what you are trying to achieve in a Marine application.




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Thank you for the reply! I did get some more info on my issue from another forum. I did not install a RH cam shaft, but you’re saying there’s also more to switching rotation than simply changing to a gear to gear setup, a RH camshaft and reversing firing order?
 
Thank you for the reply! I did get some more info on my issue from another forum. I did not install a RH cam shaft, but you’re saying there’s also more to switching rotation than simply changing to a gear to gear setup, a RH camshaft and reversing firing order?

Yes, that is correct!

A REV RH engine camshaft profile is very different from that of the STD LH rotation engine, even while driving the camshaft in the STD LH rotation direction with twin gears.
(chain/sprockets turn camshaft same direction as crankshaft....... twin gears keeps camshaft in standard LH Rotation direction)
In other words, you need the correct REV RH Rotation camshaft for this engine. Plus..... you must decide if you are going to chain drive the cam, or use twin gears!

The firing order for a STD LH Rotation SBC is 1-8-4-3-6-5-7-2
The firing order for a REV RH Rotation SBC is 1-2-7-5-6-3-4-8

For example:
When the #1 piston is on it's down stroke (intake stroke), the STD LH rotation camshaft will be opening the intake valve.
All is good......right? Not so!

This same camshaft will next open the #8 cylinder intake valve.... BUT, the crankshaft has now positioned cylinder #2 for an "intake" stroke.

The camshaft will next open the #4 cylinder intake valve..... But again, the crankshaft has now positioned cylinder #4 for an intake stroke.

This continues right down the firing order until we get to cylinder #6.
Once past #6, the problem continues until we get back to cylinder #1.



Don't forget that the piston wrist pin offset must be correct for REV RH Rotation!


And no offense to the automotive experts.... but please note that there are important aspects to the Marine build that the Automotive guys may not be aware of.
These are subtle differences, but are very important differences.
Fuel metering, ignition advance, Static Compression Ratio, Camshaft profile, etc, are quite different.









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Let me ask, what is the result if I don't reverse the pistons to compensate for the offset? what are the issues that will cause and is it minor or major?


And by no means is any offense taken, my mechanics happen to work for me and are quite knowledgeable in the automotive application but obviously lacking in the marine setup (through trial and error we are all learning a lot), and getting a marine mechanic this time of year to even spend 5 minutes looking at this is near impossible. I really appreciate your help, I may splurge on a professionally remanufactured RH marine engine if this is more complicated / involved than simply switching to gear to gear timing, RH camshaft and reversing the firing order.









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Let me ask, what is the result if I don't reverse the pistons to compensate for the offset? what are the issues that will cause and is it minor or major?
The connecting rods, during cordial-action, will cause excessive piston skirt wear on one side.
It may last for a while, but will eventually cause failure.

 
you need a gear drive and RH cam to spin the motor reversed not to mention the oil hole facing the wrong way on the rods, and the front and rear main seal difference in rotation. standard seal in a rev motor pumps oil out not in
 
Keith's last post was on the 26th. We may have lost him!

you need a gear drive and RH cam to spin the Engine reversed

We can twin gear drive a RH Rotation Engine camshaft..... similar to the camshaft that he removed from the damaged engine.
Or............., we can chain/sprocket drive a RH Rotation Engine camshaft that is designed for chain/sprocket.
Although each offers the same end result regarding valve operation, these two camshafts (chain vs twin gear) are quite different.


not to mention the oil hole facing the wrong way on the rods,
I am not aware of any oiling holes on the connecting rods.

and the front and rear main seal difference in rotation. standard seal in a rev Engine pumps oil out not in
If I may clarify...... The seal's fine spiral type serrations are there to actually "whick" in-ward, back towards the crankcase.
A standard seal installed in a REV RH Engine would work against you, in that you would see what appears to be a leaking main seal!
 
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I agree..... what this author is calling "spurt holes" (and if the rods have this feature), they must remain inward and be more-or-less facing each other.


My comment regarding reversing the piston's indexing (so that the wrist pin offset would be correct for REV RH), pertains to the pistons only.
The connecting rods would remain the same.

By the way..... good catch on the main seals for a REV RH engine........... I failed to mention that.



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I just posted this to another thread that was helping me out but thought I would add it here as another reference point...


Hey everyone,

I thought I would update everyone on my situation. My boat is back in action and running better than it did with the previous engine.
I figure I can't be the only jabroni who had a similar issue like mine so I wanted to put a more comprehensive overview of turning a LH / standard / counterclockwise engine to a RH / reverse / clockwise rotation so anyone searching for info can find it in one place. Thank you to everyone who replied and took the time to speak to me on the phone including Lee Dahlen and John from https://www.1800runsnew.com/re-manufactured-engines/.

At any rate, here is what it took for me to convert my standard LH CCW engine block taken from an '86 Camaro and turning it into a Reverse RH CW motor to match was in my 1980 Chris Craft Catalina 28.
Most of this conversion work should be done to the engine before setting it back into the boat. We used a heavy piece of timber cut to 86.5" long placed on the upper sides of the boat where the side glass sits and a chain fall to lift and lower the block in/out of place while the boat was in the water in the slip.


Essentially we replaced the cam shaft with a RH marine version which can be found here; (I pulled mine from a used marine engine my friend had) https://bpi.ebasicpower.com/shop/crusader-inboards/engine-system/camshafts
Next we replaced the rear main seal and front timing/main seal with RH marine versions found here; https://www.skidim.com/Seals-Engine/products/1031/


Next we replaced the timing chain setup with a gear to gear setup (two gears only, not three). I also pulled those from that RH marine engine my friend had, I found a set here though; http://www.psepmarineparts.biz/store/mercruiser_timing_sets.htm
you can use the same distributor or a standard one as that rotation does not affect those or the oil pump. You will need to change the firing order to 1-2-7-5-6-3-4-8.


Lastly, this is one thing we did not do, I'm told we may not get the lifespan out of the engine but at this point I think we will roll the dice, you are supposed to reverse the pistons 180 degrees to accommodate the piston wrist offset. Given my particular situation we were not in a position to go to that level.


One other thing to consider is that if your installing a different year block you may need to swap the flywheel with the correct one that has the ring gear in the proper place for the starter to engage. Otherwise we salvaged every component off the original set up that wasn't affected by the block/heads freezing and cracking from improper winterization.


And lastly, my risers were not cracked internally, I was unable to procure a new set (budget restraints) so on a hunch against the advice of Lee, we reinstalled the exhaust manifolds/risers and it seems the wrong camshaft was responsible for pulling water all the way up the exhaust.

Any experts out there feel free to correct me of course! I hope this post helps someone else in the same predicament but honestly if I had to do it again I would just purchase the rebuilt RH motor in the link above...

Thank you again to everyone for their expertise and advice! It was a huge help!!






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Any experts out there feel free to correct me of course! I hope this post helps someone else in the same predicament
Thank you and bear with me. I am taking the liberty to do so by leaving a few of my own comments along with your re-cap of events!




I just posted this to another thread that was helping me out but thought I would add it here as another reference point...
I like that..... It can be helpful when info is brought from one thread to another relative thread!


Hey everyone,

.........................

At any rate, here is what it took for me to convert my standard LH CCW engine block taken from an '86 Camaro and turning it into a Reverse RH CW Engine to match was in my 1980 Chris Craft Catalina 28.


Essentially we replaced the cam shaft with a RH marine version which can be found here; (I pulled mine from a used marine engine my friend had)
Was this a Flat Tappet camshaft, or a Roller camshaft?

.....If Flat Tappet, all of the existing "cam followers" (aka lifters) would need to be placed back over the exact same cam lobe as they had been removed from.
.....If Roller cam, this would not be an issue!


https://bpi.ebasicpower.com/shop/crusader-inboards/engine-system/camshafts
Next we replaced the rear main seal and front timing/main seal with RH marine versions found here; https://www.skidim.com/Seals-Engine/products/1031/
Yes, Bt Doctour brought this to your attention in post #7.


Next we replaced the timing chain setup with a gear to gear setup (two gears only, not three). I also pulled those from that RH marine engine my friend had, I found a set here though; http://www.psepmarineparts.biz/store/mercruiser_timing_sets.htm

I have a simple note to add regarding the basic methods in which this can be accomplished:

1..... the twin gear drive that turns the special camshaft opposite of the crankshaft's direction.
Each cam lobe profile has been changed as to correctly operate the valves for a REV RH Rotation Engine.
The camshaft's distributor "drive" gear is Standard, and requires NO change to the distributor.

2..... chain/sprocket drive that turns the camshaft in the same direction as the crankshaft.
Each cam lobe profile has been designed as to correctly operate the valves for a REV RH Rotation Engine.
The camshaft's distributor "drive" gear is now reverse cut as to correct distributor shaft direction.
The distributor's "driven" gear must be changed as to match the camshaft's "drive" gear cut!

3..... 4 point gear drive system using 1 crank gear, 1 cam gear and two idler gears. This drives the cam as does #2 above!




you can use the same distributor or a standard one as that rotation does not affect those or the oil pump. You will need to change the firing order to 1-2-7-5-6-3-4-8.
Yes..... this too was mentioned earlier!


Lastly, this is one thing we did not do, I'm told we may not get the lifespan out of the engine but at this point I think we will roll the dice, you are supposed to reverse the pistons 180 degrees to accommodate the piston wrist offset. Given my particular situation we were not in a position to go to that level.
Unless you are extremely lucky, failure to have reversed the wrist pin offset will definitely shorten the life of this NOW REV RH Rotation engine!
I hope that you prove me wrong! :D


One other thing to consider is that if your installing a different year block you may need to swap the flywheel with the correct one that has the ring gear in the proper place for the starter to engage.
Also...... keep in mind that the year will designate the crankshaft flange bolt pattern.
Early 2 pc rear main seal style bolt pattern is much larger, whereas the later 1 pc rear main seal flange is much smaller.
Not to mention that we will see both the 153 tooth ring gear flywheel, and the 168 tooth ring gear flywheel.



but honestly if I had to do it again I would just purchase the rebuilt RH Engine in the link above...






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