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318 rebuild advice

shellback

New member
Gentlemen
I just pulled the tired 1979 fresh water cooled reverse rotation 318 out of my 26ft Calkins Bartender. It has always been a more than adequate engine for my needs. It is currently at my machine shop awaiting their opinion. Reliability is my most important consideration. I already have new in the boxes Edlebrock 1409 carburetor and the appropriate Mallory Breakerless distributor. Any advice on good upgrades for the innards would be appreciated.
Cheers
 
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Gentlemen
I just pulled the tired 1979 fresh water cooled reverse rotation 318 out of my 26ft Calkins Bartender.

Any advice on good upgrades for the innards would be appreciated.
Cheers

26ft Calkins Bartender would be single engine, correct? If so, why then is this a RH Reverse Rotation engine?
Looking at the flywheel end of the engine, which hand does it rotate?

The 318 and 360 cylinder heads offer a wedge area.

images

Read up on Squish and Quench before building one, and consider a piston better suited for Marine engine loads.

Avoid this style piston. :mad:
images

There are better alternatives that will offer the Squish and/or Quench effect.
C/R and all else can remain very much the same, but Marine Engine "Detonation" potential is greatly reduced.

Here is a good article by Steve Dulcich.
It pertains mainly to Automotive and the BB Chrysler engines...... and I'll be the first to suggest that we should NOT compare our Marine Engine builds to that of Automotive.
However, this is one cross-over that can very nicely apply to the Marine Cruiser Engine.

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Reverse rotation on single screw boats is very common.

If you want reliability, buy a rebuilt long block from a quality supplier (like Vesuvio). You can't beat the price and they are already semi-broken in for you.

Jeff
 
Yep Ricardo that is looking forward prop to bow. The starter motor also is mounted to the after end and stb side of the bell housing which to my knowledge would also indicate "reverse" rotation.
In respectful response to fastjeff's response below I prefer to work with my own machinist. I know it will cost more but I can be %110 sure of his work. He has done all of the work for my automobile repair shop for 25 years. I must point out that my professional background is strictly European(37 years) thus my knowledge of domestic down draft carbureted engnes is quite honestly limited, other than the essential principles. The vehicles I specialize in produced their last carbureted vehicle(twin side draft) in 1972.
I agree Ricardo that street and marine are mutually exclusive worlds. The higher duty cycle loads of marine applications are a different animal and especially with an old school flyweight style distributor and carburetor detonation is a huge dilemma.
cheers mates and thanks for responding
Bo
 
If that's a reverse rotating engine (which I suspect it is) then tell your mechanic to put the pistons in with the "F" facing toward the back. If not, you'll have massive piston slap. I assume he already knows that (a rebuilder certainly does) and he also knows to use brass freeze out plugs and stainless head gaskets.

Jeff
 
The starter motor also is mounted to the after end and stb side of the bell housing which to my knowledge would also indicate "reverse" rotation.
Bo
Either RH or LH rotation will mount the starter motor onto the Flywheel Cover as you have described. This would be a fairly typical I/B starter motor installation.

I agree Ricardo that street and marine are mutually exclusive worlds. The higher duty cycle loads of marine applications are a different animal and especially with an old school flyweight style distributor and carburetor detonation is a huge dilemma.
Bo
Bo, marine load "detonation" is not exclusively due to the above mentioned items.
Compression ratio, piston design, cylinder head configuration, etc., etc, all play a role in this. Hence my suggestion of selecting a piston that offers an area that mirrors the wedge area of the cylinder head.... aka "Squish" or "Quench"! The selected dished area volume then controls Static Compression Ratio when used with small chamber cylinder heads.
We do this NOT primarily for a horse power increse, but for much better detonation control, which leads to better performance.

I'm not a Chrysler expert by any stretch of the imagination, so perhaps read up a bit on the topic of quench effect for this engine! Perhaps a Flat Top piston works with certain 318 cylinder heads, giving the correct C/R yet while offering the Q/E. (Flat top pistons can create a q/e with the correct head gaskets)
In a SBC Marine build, this makes a tremendous difference. Since either cylinder head (318 or SBC) offers a "wedge" area, I can't help but think that this may benefit the 318/360 Marine build as well.
The fully dished piston cannot offer the q/e, and will contribute to Detonation! :mad:
There are much better alternatives, IMO!

If that's a reverse rotating engine (which I suspect it is) then tell your mechanic to.......................
Agree with Jeff! Also, the crankshaft seals will be directional for a RH build.

An unsolicited tid bit of info; make sure that whoever you have do the engine build, understands the subtle differences between an automotive build and a Marine build.

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Thanks for the comments and advice fellows. I decided to keep it bone stock......easier that way. At tear down we found that it had been into before by hacks. The pistons had been reinstalled backwards from what they should have been for a reverse rotation engine and 3 rods had been replaced weighing 25-30 grams more than the other 6, yikes! It is all fresh and correctly balanced now and back in the boat. Next come manifolds and lots of plumbing.
 
There's either an " F " or a notch in the piston top that indicates installation direction. Putting them in the wrong way doubles piston slap damage--not good.

Jeff
 
Yes.... I agree.
But the reason for reversing the piston direction for a RH Reverse Rotation Engine, is to place the wrist pin offset in the correct orientation.
If the pistons are not ambidextrous (meaning double valve relief's).... it will not work to simply install reversed.

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"If the pistons are not ambidextrous (meaning double valve relief's).... it will not work to simply install reversed."

Rick,
You mean #1 piston cannot just be rotated 180° in cylinder #1, but it would also need to be swapped to the opposite bank??
 
Gentlemen
I just pulled the tired 1979 fresh water cooled reverse rotation 318 out of my 26ft Calkins Bartender. It has always been a more than adequate engine for my needs. It is currently at my machine shop awaiting their opinion. Reliability is my most important consideration. I already have new in the boxes Edlebrock 1409 carburetor and the appropriate Mallory Breakerless distributor. Any advice on good upgrades for the innards would be appreciated.
Cheers

I have an LM318 in my 26' Trojan that I am about to start working on and I was wondering what the part numbers were for the Carb and distributor and where you found the best deal at? I was looking at getting mine rebuilt but someone suggested getting a new one might be just as cheap. My Model # for the engine is LM318BWR10 862
 
I STRONGLY recommend buying a rebuilt long block instead of a local rebuild. The prices for Mopar rebuilds can't be beat.

I've done it both ways and, guess which way worked out best?

Jeff
 
Just to clarify: The "F" mark on the pistons should face the REAR on reverse rotation motors.

Jeff


This is false information. Jeff you and Ricardo are wrong. I just spent hours researching this because I was concerned about how confident you were with your answer. You are mistaken. Chrysler LM318 and LM360 engines have symmetrical thrust faces on either side of the piston. Because of how it connects to the rod the piston notch ALWAYS FACES FORWARD regardless of engine rotation. See figure 37 page 41.

https://www.manualslib.com/manual/1007590/Chrysler-Lm-318.html?page=41#manual


 
I had the head off my starboard, reverse rotating 360 and I can assure you the pistons had a distinctive "F" on them--and they were all pointed at the distributor end of the motor (as they should be).

No motors are built anymore without piston pin offset.

Jeff
 
I had the head off my starboard, reverse rotating 360 and I can assure you the pistons had a distinctive "F" on them--and they were all pointed at the distributor end of the motor (as they should be).

No motors are built anymore without piston pin offset.

Jeff

Agreed.
There is a reason for the markings.

Most 318/360 engines (or most any engine for that matter) are standard LH Rotation.
As each piston undergoes it’s power stroke, the entire connecting rod is NOT forced straight down.
The large end of the rod has no choice but to swing with the crank throw, of which creates a changing angle between it and the centerline of the piston.
This action places an unwanted side load on the piston.
In order to lesson the ill effects of this, the piston has been designed with an offset wrist pin.

When we change the direction if the rotating assembly, we must also change the orientation of the wrist pin offset....... hence the markings now facing opposite.

An exception to simply turning the pistons 180, would be a Quench style piston that may have valve reliefs of different sizes (for both intake and exhaust valves.)
Some engines allow for this..... some do not.


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Mike, it would behove you to lose the attitude! No one here is trying to mislead you!

Ricardo, Intentional or Not. Which I don’t believe it was intentional.....you and Jeff were both making factual statements with confidence about Chrysler LM318 engines that were incorrect and misleading to many users on this forum. It would “behove” you and Jeff to simply make disclaimers in your posts that you don’t know something for a fact if you don’t know something for a fact. I’ve read all of your and Jeff’s posts on the subject of 318 reverse rotation piston orientation in 2 different threads and both of you are saying as if you know for a fact that the pistons go in backwards on a reverse Chrysler 318. it is misleading and I’d appreciate disclaimers to your posts if you don’t know. I can agree many engines are like this but you are posting in a thread about small block Chrysler’s.
 
..."...you and Jeff were both making factual statements with confidence about Chrysler LM318 engines that were incorrect and misleading to many users on this forum."

According to who? Ricardo and I are absolutely correct, not you.

As I reported above, not only have I seen the "F" mark on the pistons of a reverse rotator aimed aft (at the distributor) as they should be, ALL modern engines have offset piston pins to reduce piston slap.

Enough said.

Jeff
 
..."...you and Jeff were both making factual statements with confidence about Chrysler LM318 engines that were incorrect and misleading to many users on this forum."

According to who? Ricardo and I are absolutely correct, not you.

As I reported above, not only have I seen the "F" mark on the pistons of a reverse rotator aimed aft (at the distributor) as they should be, ALL modern engines have offset piston pins to reduce piston slap.

Enough said.

Jeff



I respectfully disagree. I personally am currently in process of restoring 2 LM318’s and have more knowledge on this specific engine than you do. I probably don’t know more than you in general but on this specific topic I do. I see a lot of your posts and Ricardo’s and generally they are very helpful. Thank you for that. With that being said I literally just got my engines back from the rebuilder and had this specific conversation with him hence the link I included supporting my statement. If you have different supporting documents from Chrysler specific to 318s or 360’s please provide. But considering I’ve actually just had 2 engines rebuilt and provided factory documentation supporting what I said I think you should concede that you were speaking general terms on something different than the subject of the thread. In general I’ve taken most of your posts with facts as gospel. That being said for newer members like myself we would appreciate disclaimers if you don’t know something for a fact so we don’t take it as gospel from a veteran member of this online forum. There is a certain trust given to guys like you and Ricardo that post regularly by guys like me. In this instance you were mistaken and had I have been tackling this project without a professional engine builder I could have had an expensive time consuming problem by taking you at your word as gospel.
 
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"You can lead a horse to water, but you can't make him drink."

Do it your way and listen to the pistons knocking like crazy if one's a reverse rotator. (The pin offset's purpose is to prevent that, so putting them in assbackwards only makes things much, much worse.) If so, don't say Ricardo and I didn't warn you.

Jeff
 
MikeCinci said:
"you and Jeff were both making factual statements with confidence about Chrysler LM318 engines that were incorrect and misleading to many users on this forum."

According to who? Ricardo and I are absolutely correct, not you.

As I reported above, not only have I seen the "F" mark on the pistons of a reverse rotator aimed aft (at the distributor) as they should be, ALL modern engines have offset piston pins to reduce piston slap.

Enough said.

Jeff

"You can lead a horse to water, but you can't make him drink."

Do it your way and listen to the pistons knocking like crazy if one's a reverse rotator. (The pin offset's purpose is to prevent that, so putting them in assbackwards only makes things much, much worse.) If so, don't say Ricardo and I didn't warn you.

Jeff

Some people can only learn via a visit to the school of hard knocks.....

Jeff and Mark, you are both correct regarding leading a horse to water, regarding don't say that you weren't warned, and regarding the school of hard knocks.

If MikeCinci actually builds a 318 or 360 for Marine use, and if he doesn't pay close attention to the wrist pin offset, he will learn a valuable and expensive lesson.



MikeCinci,
perhaps you are confusing Mopar 318/360 automotive pistons (w/ offset wrist pins) with After Market 318/360 automotive pistons (w/ zero wrist pin offset).

Please understand that this is a Marine Engine forum whereby we discuss Marine Engines.... not necessarily automotive!
The Marine engine undergoes a completely different type of work load!

If you want to talk Automotive, you'll do much better at a Chrysler Automotive Forum.


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Like Jeff said, most will be hard pressed to find LA block pistons without an offset wrist pin.....

FWIW, not finding an item in the service manual doesn't mean there isn't worth noting.....and find something in a service manual doesn't mean there aren't errors or exceptions.....they are guides, typically for those that have been thru the associated classes....
 
Guys,

3 people have now said I’m wrong and they are right but no one except me has provided any supporting documentation so I’ll add more to prove my case. Here are pictures of the 51 year old pistons with 2800 hours on them. Those came out of the reverse rotation engine. The wrist pin is not offset and thrust walls are symmetrical.
Please provide supporting evidence if you are stating facts vs speculation. Yes I’m rebuilding Marine 318’s to whoever said that. Please if I’m wrong prove me wrong and I’ll concede.

link below has more pictures of engines and pistons.

https://share.icloud.com/photos/0MX-32PmuIhSZsY21CYoiz_Tg
 

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First Mike, you have Hy-Jacked Shellback's thread.
It would be best to start your own new thread on the topic.
Perhaps title it: "Question re; 318 Chrysler RH Reverse Rotation wrist pin offset"

Secondly, you have chosen to be rather rude with your opposing comment delivery. We have enough rudeness from several other members as it is.

This is false information. Jeff you and Ricardo are wrong. I just spent hours researching this because I was concerned about how confident you were with your answer. You are mistaken. Chrysler LM318 and LM360 engines have symmetrical thrust faces on either side of the piston. Because of how it connects to the rod the piston notch ALWAYS FACES FORWARD regardless of engine rotation. See figure 37 page 41.

https://www.manualslib.com/manual/1007590/Chrysler-Lm-318.html?page=41#manual

I have viewed page 41 and Fig #37.


Ricardo, Intentional or Not. Which I don’t believe it was intentional.....you and Jeff were both making factual statements with confidence about Chrysler LM318 engines that were incorrect and misleading to many users on this forum.
Yes, we made intentional and what we believed to be factual statements.


It would “behove” you and Jeff to simply make disclaimers in your posts that you don’t know something for a fact if you don’t know something for a fact.
I would suggest the same for you!

I’ve read all of your and Jeff’s posts on the subject of 318 reverse rotation piston orientation in 2 different threads and both of you are saying as if you know for a fact that the pistons go in backwards on a reverse Chrysler 318.
I don't recall using the term "Backwards".

it is misleading and I’d appreciate disclaimers to your posts if you don’t know.
Again.... perhaps take heed of this yourself.
I'll even go on to ask: since this is a pet peeve of yours, if you were to learn that YOU are in error, will you admit to it?


I can agree many engines are like this but you are posting in a thread about small block Chrysler’s.
We are very aware of that from the moment that we clicked on and viewed the thread!

I respectfully disagree. I personally am currently in process of restoring 2 LM318’s and have more knowledge on this specific engine than you do. I probably don’t know more than you in general but on this specific topic I do.
See my image below. I have posed a question for you.

I see a lot of your posts and Ricardo’s and generally they are very helpful. Thank you for that. With that being said I literally just got my engines back from the rebuilder and had this specific conversation with him hence the link I included supporting my statement. If you have different supporting documents from Chrysler specific to 318s or 360’s please provide. But considering I’ve actually just had 2 engines rebuilt and provided factory documentation supporting what I said I think you should concede that you were speaking general terms on something different than the subject of the thread. In general I’ve taken most of your posts with facts as gospel. That being said for newer members like myself we would appreciate disclaimers if you don’t know something for a fact so we don’t take it as gospel from a veteran member of this online forum. There is a certain trust given to guys like you and Ricardo that post regularly by guys like me. In this instance you were mistaken and had I have been tackling this project without a professional engine builder I could have had an expensive time consuming problem by taking you at your word as gospel.

Guys,

3 people have now said I’m wrong and they are right but no one except me has provided any supporting documentation so I’ll add more to prove my case. Here are pictures of the 51 year old pistons with 2800 hours on them. Those came out of the reverse rotation engine. The wrist pin is not offset
Did you actually take a precision measurement, or are you determining this by a visual only?
(the amount of wrist pin offset may not be easily seen by eye alone!)


and thrust walls are symmetrical.
Please provide supporting evidence if you are stating facts vs speculation.
Yes I’m rebuilding Marine 318’s to whoever said that. Please if I’m wrong prove me wrong and I’ll concede.
This is shellback's thread. I don't see the need to prove or disprove anything for Shellback.
As suggested earlier, start your own thread on this topic and see where it leads you!

link below has more pictures of engines and pistons.

https://share.icloud.com/photos/0MX-32PmuIhSZsY21CYoiz_Tg


In my image below (using PDF page 41, fig #37 and your actual piston photo), I show what appears to be a difference in dimensions between the wrist pin and the sides of the casting relief areas.
It is easy to see on the PDF image, but
since the actual piston photo is not a direct or square shot, it is difficult to see the dimension from wrist pin to piston skirt.

Nonetheless, I will ask you if you are able to explain why these dimensions appear to be different?


Chrysler 318 360 wrist pin offset .jpg
 
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