Carburetor to Heat Box on CC340 Engine

[karaka29211]

With reference to Section 9 about Carburetor Air Box fitment to the carburetor, there is a part number SP54300-001 included in Figure FF8 on page 19 of the Firewall Forward Manual. There is no mention of any such part in the text, nor the Packing Slip, but it seems logical that a gasket should be fitted between this components.

Anyone know for sure? Is there a carburetor/Heat Box gasket included in the kit?

[Pete D]

There should be a gasket between the airbox and the bottom of the carb. Not sure where it would be in the kit. Possibly packed in the box with the carburetor.

[karaka29211]

Thanks for confirming the need for a gasket, there was no gasket in the sealed carburetor box. Can you confirm that SP 54300-001 is a gasket, it looks like it should be from FF08. That suggests it is a CC part, rather than associated exclusively with the carburetor.
There was a gasket between the carburetor and the sump which was replaced after removing the sump cover plate. That gasket does not fit the air box, so there should be another gasket somewhere else.

There should be a gasket between the airbox and the bottom of the carb. Not sure where it would be in the kit. Possibly packed in the box with the carburetor.

[Pete D]

Thanks for confirming the need for a gasket, there was no gasket in the sealed carburetor box. Can you confirm that SP 54300-001 is a gasket, it looks like it should be from FF08. That suggests it is a CC part, rather than associated exclusively with the carburetor.
There was a gasket between the carburetor and the sump which was replaced after removing the sump cover plate. That gasket does not fit the air box, so there should be another gasket somewhere else.

Affirmative, SP5300-001 is a gasket, and different than the one that goes on top of the carb.

[jmorrical]

Continuing this thread with carburetor installation question.

Carbon Cub EX(1)
Serial # CCK-1865-0110
Executive Glass-G3X

Mounting carburetor.

• Are people using some special tool to torque those carburetor mount bolts or guessing? I can torque the forward two bolts with my 1/4" drive torque wrench and a 3/8" drive adapter and crows foot, but can not reach the rear mount bolts with this. I need a longer arm on the crows foot tool. I have found a Motion Pro Torque Adapter that attaches to a simple wrench to extend the reach to torque in tight spaces.

• My EX Firewall Forward Manual says carburetor mount bolts are torqued to 90 in-lbs. The CubCrafters CC340 Engine Manual on page 7-57 says 90 in-lbs then 204 in-lbs.

1. What do I use to get the bolts torqued?
   
2. Why the discrepancy in torque values in the manuals?

Screen Shot 2022-02-11 at 3.44.31 PM.png

Screen Shot 2022-02-11 at 3.31.52 PM.png

[Pete D]

With reference to Section 9 about Carburetor Air Box fitment to the carburetor, there is a part number SP54300-001 included in Figure FF8 on page 19 of the Firewall Forward Manual. There is no mention of any such part in the text, nor the Packing Slip, but it seems logical that a gasket should be fitted between this components.

Anyone know for sure? Is there a carburetor/Heat Box gasket included in the kit?

Yes there should be a gasket on the top and bottom of the carb. They are usually similar material but slightly different sizes,.
SP54300-001 Carb gasket (bottom) is included in the engine kit.

[jmorrical]

I found some interesting installation detail about the Garmin carburetor temp probe (1B10R) SP71329-001 that is to be installed on my engine carburetor.

Screen Shot 2022-02-16 at 2.17.02 PM.png

Threads are not to extend into the throat of the carburetor. See the diagram below. Mine came with only one small washer and it's not enough. I believe I need the ‘special’ star washers + a couple other copper washers shown below to make the installation IAW the specification. They were not included.


Anyway this screen shot below is from the Mid-Continent Instruments + Avionics where they make TSOd version of the probe. I used their installation manual to supplement the Installation Instructions that were included in the little box with my probe from CubCrafters. It mentions special star washers and flat washers that I needed.




From: Mid-Continent Instruments + Avionics installation manual

Screen Shot 2022-02-16 at 2.16.34 PM.png

Screen Shot 2022-02-16 at 2.18.31 PM.png

[ceslaw]

Jim: Good information. Plan to check on that issue when I install the carb.

[jmorrical]

Pete at KitSupport has clarified the discrepancy between the EX(1) Firewall Forward Manual and the CubCrafters CC340 Engine Manual as it relates to torque values. See the entry earlier in this thread.

The carburetor mount bolts are to be torqued IAW the CC340 Engine Manual page 7-56 as shown below.

Screen Shot 2022-02-11 at 3.31.52 PM.png

This torque adapter was new to me, but I used it to torque the hard to reach nuts. 3/8" drive in various sizes are available at Grainger, Northern Tools, etc. $20+

BTA162A_ProductImage_PrimaryImage_400.jpg

Screen Shot 2022-02-20 at 11.37.42 PM.jpg

[Daveembry]

Just a note on using a crows foot/adapter on a torque wrench. You have to recalculate the correct torque displayed. The longer the adapter, the less displayed torque. Here is a link to a post I did on torquing the prop bolts on an EX3 that requires an extention and explains how to calculate it (formula). Its down in the post.

https://forum.cubcrafters.com/showth...ll=1#post22674

Pete at KitSupport has clarified the discrepancy between the EX(1) Firewall Forward Manual and the CubCrafters CC340 Engine Manual as it relates to torque values. See the entry earlier in this thread.

The carburetor mount bolts are to be torqued IAW the CC340 Engine Manual page 7-56 as shown below.

Screen Shot 2022-02-11 at 3.31.52 PM.png

This torque adapter was new to me, but I used it to torque the hard to reach nuts. 3/8" drive in various sizes are available at Grainger, Northern Tools, etc. $20+

BTA162A_ProductImage_PrimaryImage_400.jpg