Crankcase stuffing the easy way

[ChrisCarsonMarine]

New Crankcase Stuffer Plates from Chris Carson's Marine Service

An Easy and Fast Modification For Mercury Engines▼

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Chris Carson’s Marine is adding several new products to compliment our reed valves and spacer kits, focusing on the small block V6 Mercury engines.

This is an inexpensive modification that can easily be performed while changing the reeds, with no added strain on the engine and no penalty to long-term reliability.



Now available are new intake stuffers that mount between the reed blocks and intake manifold, reducing the crankcase volume by moving the reeds into the crankcase .065-inch. This modification results in the exact same gain as with the common practice of milling the front half of the crankcase, but without the need to tear down the engine or any machine work.



The five and seven-petal versions are available now and ready to ship, with an even more effective version for the four-petal engines becoming available within a few days.



Chris Carson's Marine Service will be offering other valuable engine crankcase stuffer products for other engines very soon.

[Bruce2]

Whats the performance gain using these on a stock engine along with your reeds?

[gaboy]

congratulations chris on another great product. I know it's probably been a year in the making since we talked about this. david

[ChrisCarsonMarine]

David, thanks for your encouragement. We are so busy that it seems to take a couple of years to get an idea from the desk to the machine room. I’m happy to finally get them done, the 3 L stuffers
should be available soon, As well as a couple of other parts for 2.4’s and 2.5’s that I think the rebuilders will like.
Bruce, going from steel to composite reeds usually results in a better idol and better mid range pull sometimes a little better top end. In the case of mercury steel reeds it’s a good idea to replace them with composite just for safety sake,as the steel ones are known to chip and break often.As to the gains expected from the stuffers, I don’t have any real research to call on. At this point,I can only go by the fact that all the high performers engine builders I know include crankcase milling in their builds...I’m confident it helps,and using the stuffers results in actually more cc’s removed than the milling procedure.
Logic would have it that there should be a gain, right now I just don’t have a way to measure it.I have everything in boxes to fully computerize my Stuska Powerhead dyno,hopefully I’ll have time to set it up soon so I can see some more reliable results in testing,Thanks for your interest,Chris

[wbh1954]

Good Idea

[John Jackson]

It reduces crankcase volume, which increases crankcase pressure in 2 ways. The reduced volume with the same swept volume increases the velocity of incoming air, and once the reeds are closed, the piston comes down and due to lower CC volume,, crankcase pressure is higher. So when the port opens, more and higher pressure fuel/air go into the cylinder.

[Rich Z]

Good idea Chris! Be happy to have them in our inventory along with current selection of your reeds.

[caddelma]

How would these work along with the 1 inch intake spacer on a mostly stock 200hp Xri (CCMS reeds already installed)?

[ChrisCarsonMarine]

Good idea Chris! Be happy to have them in our inventory along with current selection of your reeds.

You will have them in stock in a few days,chris

[ChrisCarsonMarine]

How would these work along with the 1 inch intake spacer on a mostly stock 200hp Xri (CCMS reeds already installed)?

The spacer plate improves the flow of the intake tract,helping acceleration,and the stuffers raise the crankcase compression...the results should be noticable,Chris

[caddelma]

Still able to run 87 octane I assume versus having the heads cut?

[ChrisCarsonMarine]

Still able to run 87 octane I assume versus having the heads cut?

+No need for higher octane fuel,Chris

[EuropeanAM]

Nice, Chris. Especially cool that it's not a "one-way street" like cutting cases.

[ChrisCarsonMarine]

Thanks Don,enjoyed our talk,And your insights,Chris

[nitromorris]

Would adding this to a block that the front has been cut help the performance of the engine ?

[ChrisCarsonMarine]

Would adding this to a block that the front has been cut help the performance of the engine ?
There Mary or may not be room to add the stuffers is the crackers as already been cut. 705 Pearl

There may or may not be room to add the stuffers if the crankcase has already been cut. There probably won’t be room with 7 or 5 petal cages,but if you have the rubber coated 4 petals I think they will fit,Chris

[boatdoctor]

Would like to see the pics ( crank stuffers ) , for the 4 petals rubber coated cages ...... are ready available ?

[ChrisCarsonMarine]

Go over to Screamandfly and go to articles.They were introduced there and pics and descriptions are there,we also have the 3.0 Merc stuffers available now,Chris

[boatdoctor]

10-4

[boatdoctor]

Would like to see in youtube , how to install a set of stuffers on the 4 petals cages ..... Thanks