Perkins Exhaust Elbows and Flange

Helpful tips on identifying your exhaust elbow & flanges on your Perkins (Part 1) - Tech Tip #60

Exhaust mixing elbows and flanges are found on all fresh water cooled marine engines. These parts need to be replaced often because of their location and exposure to salt water. Unfortunately most are not supplied by the engine manufacturers and so can be difficult to identify. This Tech Tip, one of a series we publish, focuses on identifying mixing elbows and flanges used on 4 cylinder Perkins marine diesels.

The illustration below shows the four most common elbows and the two most common flanges used on four cylinder Perkins diesels.

A. PN ELBOW A

This elbow stands 6" tall, has four bolt holes on the bottom (3.25" by 2.5") and is common on 4108's. It is sometimes identified as PN 3776713.

B. PN ELBOW B

This elbow is 7" in overall diagonal length, male threaded (2.25" OD) on one end, no threads (1.75"ID) and is used on 4108's and 4154's. Used with Flange A (see G.).

C. PN ELBOW C

This elbow is 7" in diagonal overall length, similar in dimension (2.25" OD by 1.75" ID) to ELBO B but is unthreaded at one end and female threaded at the other. It typically uses a five bolt mounting flange. It is found on 4107.

D. PN ELBOW D

This elbow is 9" in overall diagonal length, one end is female threaded and 2.75" ID, the other end 3" OD, unthreaded and found on 4236's.

E. PN ELBOW E

This elbow (sometimes referred to as a 15017 elbow), not pictured above, is large, dome shaped, and resembles a deep sea diver's helmet. It is usually found only on Navy Whaleboats with Perkins 4107's.

F. PN ELBOW F

This elbow, also not pictured above, is 6.5" tall, female threaded (1.875" ID) on one end for a four bolt flange to the manifold, and unthreaded (1.5"ID) at the muffler end. This is commonly found on 4107's or Westerbeke 40's. The Westerbeke PN is 33067.

G. PN FLNG A

This four bolt flange (2.5" by 3") with a 2.5" OD bolts to the late style 4108 heat exchanger/exhaust manifold (PN PE 180) and accepts ELBO B. it is sometimes identified as PN 37426472.

H. PN FLNG B

This five bolt flange, (2" by 2") with 1.75" OD bolts to early style 4107/8 exhaust manifolds and accepts several elbows including ELBO E. it is sometimes identified as PN 0380203.

We hope that the above chart is useful. To help us expand it we are offering $25 Foley Gift Certificates to any readers who can identify other Perkins elbows and flanges. Please call with your suggestions.

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