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  #1  
Old 01-27-2007, 04:18 AM
N62XS N62XS is offline
 
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Location: Hazlehurst, GA
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Default Narrow Deck Lyc vs Wide Deck Lyc?

Any thoughts, good or bad, on the differences, other than age, on the use, overhaul and maintenance of a narrow deck lycoming versus a wide deck lycoming?

All input appreciated.
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Robby Knox
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  #2  
Old 01-27-2007, 06:01 AM
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RV6_flyer RV6_flyer is offline
 
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Location: Uniontown, PA
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Default

/
Quote:
Originally Posted by Hard Knox
Any thoughts, good or bad, on the differences, other than age, on the use, overhaul and maintenance of a narrow deck lycoming versus a wide deck lycoming?

All input appreciated.
Robby:

I have been flying a 1961 vintage NARROW DECK O-320 B2B that I rebuilt to new specs and converted to Constant Speed operation in my RV-6 for 1,977 hobbs hours / 1905 tach hours since September 1997.

No problems with the engine since installing it.

The conical mount isolators are CHEAPER and I cannot tell the difference in vibration than I can with the more expensive dynafocal mounted engines.

10 years ago, there was NO problem or issue with getting parts and the same outfits are sill in business supplying parts now.

If you can purchase a narrow deck engine for LESS than a wide deck, I would buy it. IF they both have the same price / history / hours, it is your pick.
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2,900+ hours

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  #3  
Old 01-27-2007, 06:03 AM
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rvator51 rvator51 is offline
 
Join Date: Jan 2005
Location: Peoria, AZ
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Default

Quote:
Originally Posted by Hard Knox
Any thoughts, good or bad, on the differences, other than age, on the use, overhaul and maintenance of a narrow deck lycoming versus a wide deck lycoming?

All input appreciated.
Hi Robbie
I will have to let the engine experts speak to the technical differences between the two types, however, Katie and I have one of each. Not much difference in use and maintenance between the two once they are installed. One thing is our narrow deck doesnt have the machined area in the case for the alternator mount.

From an owners perspective, I would rather have the wide deck than the narrow deck just because it is a newer design.
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Thomas Velvick
Peoria, AZ

N53KT RV-4
N7053L RV-4 (RV4chick's blog)
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  #4  
Old 01-27-2007, 02:02 PM
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rvpilot rvpilot is offline
 
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Default Hummmm! Let's see...

You use different wrenches to tighten the cylinder nuts!
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Based 9A1 (Covington, GA)
RV6A - Gone, but not forgotten!
RV8 - Gone too, now winning races in the RV Gold Class!
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  #5  
Old 01-27-2007, 04:56 PM
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gmcjetpilot gmcjetpilot is offline
 
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Default Agree

Technically the wide deck is stronger and has thicker cylinder base flanges. What does that mean? Well like all the post above which I agree with 100%, no much. I having both narrow and wide deck engine. If you are going to hot rod and engine or run hard or race, you may want a wide deck engine. Other wise it does not matter if you build the engine stock.

Quote:
Originally Posted by RV6_flyer
The conical mount isolators are CHEAPER and I cannot tell the difference in vibration than I can with the more expensive dynafocal mounted engines.
I gather there is a correlation between narrow deck and conical mounts. I was not sure of the relationship but I assume most conical mounts are on narrow deck engines. Later year engines all went to dynafocal and wide deck.

I did have a RV-4 with narrow deck and conical mounts. I personally prefer dynafocal but conical is OK. Dynafocal is better and more stable, less engine movement and sag.

Just my opinion and experience but I found the less expensive CHEAPER conical engine mount bushings are not very good. You can get a set for $30, verses $80-$90 a corner for Lord mounts.

Her is my experience with conical mounts. I would not use the standard bushings. Lord Corp. makes vibration isolators (engine mounts) for conical engines, which are similar to the dynafocal ones.

The Lord isolators for conical mounts are as expensive as dynafocal vibration isolators. I would not personally run plan engine mount bushings in a RV with a conical mount engine and plan bushings. I found they wore out in no time, especially when doing acro. Also I had vibration issues. All this greatly improved when I installed the Lord mounts for conical engines.

[If you look at an RV-4 steel engine mount weldment, one of the top corners of the engine mount is just a strut. That top corner takes no torque or shear, just fwd / aft loads. It is not made like a dynafocal weldement. This design puts more force on the lower corner on the same side. I found the bolt worked through the conical mount rubber bushing in no time. Also you can never torque conical mounts bushings. You just tighten till the rubber squeezes out around the big washers (which are special piper parts not AN parts). With the LORD mounts there is a spacer and the pre-load is easy to obtain. The LORD mount is just better and gives more vibration damping. Now I ran and extend hartzell metal prop. If you have a wood prop vibration (buzz) may not be an issue. ]

There are other threads on conical v. dynafocal. The good news is if you buy a core to rebuild it is not too much money to have ECI machine dynafocal mounts into the case, however it must be done with a engine tear down and case overhaul. You can call ECI or look at the other threads on the subject.

No disrespect to RV6_flyer, he is right, the narrow deck/conical gets the job done. If you found one cheap in good condition, buy it.
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Last edited by gmcjetpilot : 01-27-2007 at 05:20 PM.
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  #6  
Old 11-01-2009, 12:07 PM
beulahm beulahm is offline
 
Join Date: Oct 2009
Location: Canton, CT
Posts: 1
Default Conical Mounts

I have a Lyc 0-360 C2A with conical mounts. I am starting to get a bit of vibration after 10 years of use in my RV6A, and plan to replace the mount bushings with new ones. I ordered the new parts which are simply rubber pieces. Probably a dumb question but there is no metal bushing that inserts through the hole in the rubber parts. Do I need a metal bushing, or do I just use the rubber parts only? Thanks
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  #7  
Old 11-01-2009, 12:32 PM
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Ron Lee Ron Lee is offline
 
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Posts: 3,271
Default

I have a narrow deck O-360 and have the holes to mount an alternator bracket. Not disagreeing with Tom since he may be using a term I don't know about (very likely).

I will verify with my engine guy but I think I have a dynafocal mount.
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  #8  
Old 11-01-2009, 01:02 PM
Bob Hoffman Bob Hoffman is offline
 
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Posts: 202
Default

beulahm,
I've been looking for a 0-360 with conical engine mount -- what certified AC used them ??
thanks
Bob
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  #9  
Old 11-01-2009, 01:09 PM
noelf noelf is offline
 
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Location: Cary, N.C.
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Default I read about this a few week ago...

...I think it was in the paper rag called GA NEWS. The narrow deck came first, and through the normal evolution of higher compression ratios and more horsepower, a beefier attachment of the cylinder barrel-to-engine case became necessary. The solution became the wide-deck.

If you are looking at engine solutions involving high(er) hp and compression ratios, etc, you may want to go the wide deck route.
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  #10  
Old 11-01-2009, 01:15 PM
matt matt is offline
 
Join Date: Nov 2005
Posts: 125
Default

Quote:
Originally Posted by noelf View Post
...I think it was in the paper rag called GA NEWS. The narrow deck came first, and through the normal evolution of higher compression ratios and more horsepower, a beefier attachment of the cylinder barrel-to-engine case became necessary. The solution became the wide-deck.

If you are looking at engine solutions involving high(er) hp and compression ratios, etc, you may want to go the wide deck route.

Yes, it was in GA news:

I recently received a question from a friend of a friend in Texas regarding the difference between a “Narrow Deck” and a “Wide Deck” Lycoming engine. This has been confusing to many, so let’s see if I can shed some light on the subject.

The difference between a Narrow Deck (ND) and a Wide Deck (WD) configured engine is easily determined by checking the specific engine serial number. The WD serial numbers end with the suffix “A,” such as L-0000-36A on an O-360 series WD compared to L-0000-36 on a ND.

There are a few exceptions to this, such as the O-320-H series and O-360-E series, neither of which have the suffix “A” but still contain WD cylinders. The design of these cylinders is considerably different from conventional engines, so there shouldn’t be any confusion once you’ve looked at them. The rocker arm configuration alone would be enough to alert you that they are not interchangeable with a standard cylinder.

One of the most noticeable differences is that WD cylinders are retained to the crankcase using a standard hex nut, while a ND cylinder utilizes a barrel type, internal spline nut with a “banana plate” that is installed over the cylinder flange for additional integrity.

The best way to tell the difference is to set a ND cylinder and a WD cylinder side-by-side on a work bench. The difference you’ll spot right off the bat is the thickness of the flange. This is considered the “deck” and the WD is thicker.

My guess is that this design came about when Lycoming began to increase horsepower and compression ratios of its engines. Prior to the WD cylinder, most engine compression ratios were 7.30:1, with none higher than 8.70:1. This, coupled with the fact that most TBO times were no more than 1,200 hours, worked out just fine. The WD cylinder was one of the things that allowed Lycoming to increase the engine TBO times over a period of time.

In 1963, when Piper introduced the PA-30 Twin Comanche, it used two IO-320-B1A engines, which used the new WD configuration. There was never a PA-30 delivered with anything but a WD engine. That set the stage and the WD cylinder was phased in on other Lycoming engine models from that point.

In the eyes of the FAA there is no difference between a ND and a WD engine in any of the Type Certificate Data Sheets. Therefore, it’s conceivable that on a Piper Navajo PA-31 you could have a TIO-540-A2C WD engine on the left and a TIO-540-A2C ND engine on the right.

Can a WD engine replace a ND engine? The answer is yes. You will probably have to trim some of the engine baffling to fit over the slightly larger WD cylinders, but this can be accomplished while still maintaining the proper fit for the cooling requirements of those baffles. What you can’t do as easily is install a ND engine in place of a WD engine unless you’ve got a “baffle stretcher,” which I’ve never even heard of, let alone seen, but you get my point.
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