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db9146
Got a question on the heater control flapper valves on a -6. On mine, the driver side flapper has a solid cap over one side of the flapper valve while the passenger side flapper valve has a hole about 1.5" in diameter in the cap.

Click to view attachment


Anyone know the a reason for the one having a hole?

mepstein
The one with the hole is original. I’m pretty sure the solid one is a replacement.
Socalandy
for 914 and 914-6 there is a left and right. both -6 boxes have the hole as a air bypass
Garland
Reference for a 1.7

Click to view attachment

The “hole” has a cover over it.

Click to view attachment
rgalla9146
Trivia.
It's not just the hole on the 6 valves, the corresponding 4 cyl. part is larger in diameter.
4cyl. are black, 6cyl. are grey
mepstein
Rory - if I drilled a 1 1/2” hole in the top of my (four) valves, would it duplicate the sixes in function? Or is their an internal difference.
rgalla9146
QUOTE(mepstein @ Dec 4 2017, 10:30 AM) *

Rory - if I drilled a 1 1/2” hole in the top of my (four) valves, would it duplicate the sixes in function? Or is their an internal difference.


Hey Mark
The differences I noted are visible from the outside.
I believe they function exactly the same.
A 4cyl. part with a hole in the cover should be fine.
The function of different diameter caps ? Dump capacity ?
mepstein
QUOTE(rgalla9146 @ Dec 4 2017, 12:17 PM) *

QUOTE(mepstein @ Dec 4 2017, 10:30 AM) *

Rory - if I drilled a 1 1/2” hole in the top of my (four) valves, would it duplicate the sixes in function? Or is their an internal difference.


Hey Mark
The differences I noted are visible from the outside.
I believe they function exactly the same.
A 4cyl. part with a hole in the cover should be fine.
The function of different diameter caps ? Dump capacity ?

I'll buy that. The 6 fans move a lot of air.
Thanks!
db9146
So if the hole is only there to dump air, then wouldn't you potentially want them w/o holes to pump more air over the heads on a -6 for cooling?

mepstein
QUOTE(db9146 @ Dec 4 2017, 02:43 PM) *

So if the hole is only there to dump air, then wouldn't you potentially want them w/o holes to pump more air over the heads on a -6 for cooling?

I think you also need to cool the headers (inside the air box) with some airflow.
mlindner
Sorry to go off track but this question just came up today at Accumoto.
(Are the heater control boxes the same....or can be the same on the four and the six). If we bought new ones for a four they would work on a six?. Best, Mark
GeorgeRud
Either will fit and work, but the hole in the ones for the sixes must have been there to bleed off more air when the heat is turned off.
Socalandy
Yes but and will have a slightly different angle going to the longs
mepstein
Homemade 6 flapper box.
Found a couple rusty ones.
Blasted, cut hole, powder coated.
raynekat
QUOTE(mepstein @ Dec 12 2017, 10:44 AM) *

Homemade 6 flapper box.
Found a couple rusty ones.
Blasted, cut hole, powder coated.


Those look great.
What did you use to make the hole?
And how big is the hole?
Might go this way with 914 heater boxes for my six conversion.
mepstein
I think it was 1- 1 1/4”. It was a wurth hole saw that I chucked into the drill press. Drilled the hole, blasted the piece and then powder coated. I had 5 that were pretty rusty but still usable. I hope to make a pair or 2.

I think bdstone charges ~$50 for refurbished flapper boxes. By the time you throw out the broken ones, fix the ones that can be fixed, blast and powder coat, $50+ is a good deal.
DRPHIL914
I sent mine to bruce to be done, he has many of them in his stash, turns out my seals were in good condition , just a bit of cleaning and repainted- but if you are missing anything talk to Bruce he probably has it.
sixaddict
Great information ……
Thanks!! beer.gif
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