5 Petal Reed Blocks

[nitro_rat]

I've been tearing down a bunch of old motors (cleaning out the shop during this Corona lockdown) and thought I'd post up some stuff about 5 petal cages...


Old style in the background with reed stops, new style in the foreground without reed stops.


Reed stops are to have .300" opening on 175's and 200's, .200" for 150's...


Here are the reeds from the old style blocks.


Here are the reeds from the new style.

Both reeds are .017" thick.


The new style block has a groove machined at the base of the reed openings. The new style blocks have smoother inside contours with less casting flash than the old style.


Note how far into the airflow the stock screws (bottom) protrude. The cage on top has Boyesen reeds fitted with shorter screws for better airflow.


Here is a cage with the Boyesen reeds fitted.

I have some Carson amd TDR reeds for these cages, I'll post pics of those later when I dig them out!

It is possible to cut these "teardrop" cages to a "square" shape. This is best done on a mill. I believe Jay Smith can provide this service if desired.

Here is an old post by Jay about this modification:
https://www.screamandfly.com/showthr...-Oer-rectangle

And here is a pic of the cut cages (stolen from Jay's thread above):


The shape of the TDR reeds lend themselves to Jay's reed cut shown above.

[nitro_rat]

Here are the TDR reeds from Jay Smith.



And the set from Chris Carson.

[Merc 2.5]

Yes can b cut square it Carson makes a square reed for the modified cages , stock shape reeds on square cage idk , I'd say the square would have to b little smaller than square with custom reed

Since I have a square reed already. Just square cages

[nitro_rat]

Also I'll note that the late model 4 petal rubber coated reed blocks interchange with the 5 petal blocks in HORIZONTAL front applications.

By the time you grind the vertical front enough to put the 4 petal cages in you negate any benefit of making the swap by adding more volume to the crankcase!

Chris also makes a reed for the 4 petal cages with the rubber coating removed but that's a story for another time...

[Merc 2.5]

Ya. I guess I was actually referring to the 4 pedal also , once he grinds rubber away allows for wider reed. The factory tear drop reed shape on Tear drop cage dosent allow for alot of opening up, almost need custom reed , also cage cracks easy once squared off if gets little thin ( which cant help to)

[Chaz]

Also I'll note that the late model 4 petal rubber coated reed blocks interchange with the 5 petal blocks in HORIZONTAL front applications.

By the time you grind the vertical front enough to put the 4 petal cages in you negate any benefit of making the swap by adding more volume to the crankcase!

Chris also makes a reed for the 4 petal cages with the rubber coating removed but that's a story for another time...

Anytime you can help the induction side of any motor you will pick up power. Even if you lose a little crankcase compression. If you do it right, the case will become more volumetric efficient and fill up said void ..

PS .. working a block back at the entrance does … well nothing ...
As depicted in your own picture, that area is covered by the reed. maybe if you could come up with a devise that lifts the whole reed, you would find quite a bit of potential airflow.




Until then we are stuck with airflow straight out the nose of the block. More important is how the air leaves the block and joins back together as a column.

[nitro_rat]

Chaz, that area is covered by the reed stop in the early cages. The reed stop is not present on any cage manufactured after 1983 or so...

[nitro_rat]

Added photo of CCMS reeds to post #2.

[Chaz]

Chaz, that area is covered by the reed stop in the early cages. The reed stop is not present on any cage manufactured after 1983 or so...

Depending on model. Lotz of rubber~baby~buggy-bumper reed blocks out there with stops … Being as conservative as I am, I think the reed shouldn't be free to whip around from the hinge point, like a flag on a windy day. So when I built oversized billet blocks, I had my laser guy cut 100 "shorty" stainless plates. I rolled the tip back to the hinge point, so the reed would have something to "roll around" as it opened.





Chris Carson also does a killer reed for the "cleaned up" stock rubber blocks. Great pedal to block engagement and an 11% increase of window area, before any block porting.
(Pi R square/2 cakes are round) ...
This set has the screw bar, the other set I'm .. OK ,, my wife does em . Is getting clipped stops.



I usually don't go out of my way to prove myself wrong ... But it's hard livin inside of my head, without knowin or finding the truth ...

Going by your picture above, the spec is .300" opening. Unless anyone crawled inside to have a quick peak, we can't say for sure if it uses some, all, or want's more lift. but lets use that number ..

Ink pen, closer to .350 , piece of 5/16" molly tube, to hard, this looks like it's close .. yup .. good enough.



Now I'm much more experienced in putting things other than pencils in my reeds, but hey .. I gotta start somewhere ..





While I expected a much longer 3.0L reed to look like a banana, I have to say the majority occurred back at the hinge point. You guys pick the percentage of "window loss" at full open … Looks like no more than 15 - 20%



Don't look like the shorty's did to good … Maybe it's just the reeds .. judge for yourself ..

One~zi …

While the pedal did open and expose the back side, it appears to have this yellow thing blocking the hi-flow exit area .. Duuuu



Maybe things will get better .. at two ..

Whoop there it is … nice color to go along with the bannnnannnnna shape .. Lookin like 40 - 50% If I'm biased .. please tell me ..



OK I give up .. what freak act of nature has to happen to get the third and forth leaf's to open when there are two already open .. is there a second surge as the piston slows from 90 BTDC to TDC … NOPE
By the looks of it, two open will flow less than one. With no center, that inner really looks weak …



Now that I cut my ^^^^ down, what did these old antiques come on and what are they worth .. askin for a friend …





Naturally, I'd be inclined to throw in a set of Carson reeds and spacers ..

[spybot]

Chaz, that area is covered by the reed stop in the early cages. The reed stop is not present on any cage manufactured after 1983 or so...

Does this apply to OMC as well ???
What is the max opening for a set of 140hp Crossflow ????

[Zonkercraft]

The carbs are WH-46's with the SST 120/140 slosh tubes and probably baffles. It also has the front air velocity plate. They came, in stock form, on 2.4 200's oval and Bridgeports, along with the SST motors. Still used today on SST 120's, and is one of the legal carbs for the NGK F1 2.5 motor. A really good set will bring $375 to $400...works down from that level.

[nitro_rat]

I know from experience that the 2 stage Boyesen's work. Anybody else ever have an otherwise stock 2.0 vertical motor wind over 8k? And this is with the original black set, not the "improved" yellow and black set that they sell now for the vertical motors...

[nitro_rat]

Does this apply to OMC as well ???
What is the max opening for a set of 140hp Crossflow ????

I don't know anything about those, almost all of my outboard knowledge is Mercury V6 related...

[Jay Smith]

TDR offers reeds for ALL outboards and is offered in different thickness and weaves I’ve been running the TDR reeds on EVERY motor I’ve built for 25 years with zero issues ..
Josh I wish you would have brought those hour glassed shaped cages I could have cut them while you were here ...

Jay

[Chaz]

The carbs are WH-46's with the SST 120/140 slosh tubes and probably baffles. It also has the front air velocity plate. They came, in stock form, on 2.4 200's oval and Bridgeports, along with the SST motors. Still used today on SST 120's, and is one of the legal carbs for the NGK F1 2.5 motor. A really good set will bring $375 to $400...works down from that level.

Thank ya Zonk, for the accurate assessment …
I have a bunch of that kind of stuff I need to put in the Misc. sale section .. If I ever get caught up a@ my day job …

CH3NO2_Rat seyz :

I know from experience that the 2 stage Boyesen's work. Anybody else ever have an otherwise stock 2.0 vertical motor wind over 8k? And this is with the original black set, not the "improved" yellow and black set that they sell now for the vertical motors...

First set of two stage reeds I bought and installed were for a brand new 1973 RD-350 . So should I say .. Y .. I been a usin them for 47 years … No of course not, time and technology changes week to week, in the high tech world, daily.
I can't speak for 2.0L Merc's , what prop, weight etc. But I can say that I have sold a lot of aftermarket reeds at various bike shops, put DT-250 blocks and 32mm Mikuni's in RD's, IT-175 blocks in early Tri-Moto's , built my own billet blocks for sportjet / 3.0L's , spent enough time on a flow bench to see what actually works, but more importantly why something doesn't really work, no matter how much it's hyped.
I asked a question about what open's the second reed on a twin leaf set-up. I expected crickets and got them. Anyone with a bit of uncommon sense would put a restrictor in their shop vac hose, drop a reed block in a front half and push- pull some air thru the front and rod slot .. and see for themselves. I think the pocket protector crowd would call what they saw, hysteresis.
Everybody has their opinion and favorites. Loyalty is a good thing and sometimes even to a fault. I grew up not far from Crane cams. Raced with and against guys that worked there. After the old man passed, they got behind. A few branched out as Race cams Inc. Crane bought out Cam Dynamics , and had the latest grinds. My buddy Chase retired not long ago, not sure where they stand … might be "stuck" with history repeating itself, or perhaps got some new blood from the "conglomerate" in there and could be better than they ever were. Before I bought a cam or a half a dozen of them to flog on the dyno, I'd go see if they still had a Burco grinder and a craftsman who can operate it with his eyes closed, or a kid that spins in circles while playing with his cell phone and his job come in somewhere at the bottom of his personal list.
I do my best to be open minded and learn something new every day. One thing that has been proven to me over and over again, is, the only people that are truly behind the times, are the ones who already know everything …

I have another question or three :
Why do people put "Mercury Racing" decals on everything they own ?
Are they sponsored by Mercury ?
Does Mercury pay contingency check's to race winners + R/U , and they hope to cash in ?