[Sangster~bbc]

hey guys just was wondering if there was a correct way to adjust the cav. plate, i have a 1974 sanger flat 427bbc casale 10deg. 12per. i just went out last week unloaded her and lossend them all off and tightend them all just so they were snug could still wiggle them a bit. Just wondering if there was a correct measurement that they were to be set too!!!!
Im having trouble keeping the nose down around 80mph, but i still beat a egg beater yeasterday raced a 21 foot, cougar tunnel with a 275 virado in the guarter and spanked him haha, thanx guysdevildevilhand

 

[stix818]

I'm by now means a bottom expert (especially on a true flat) but in the past we've set the plates as a starting point using a straight edge (until Wayne Mettler could work his magic!!). Ran the straight along the bottom to the edge of the plate and adjusted the turn buckles accordingly. I believe we set my plates initially (keep in mind mines a runner bottom) 1/8" above the straight edge. Hopefully someone will chime in with better knowledge and experience with your combo.

 

[fast76rogers]

adj.

handi have a 74 sanger gullwing.all i can say is have fun.took me two weeks and five trips to the water.but i got her running good.

 

[norcal73]

I have found the continuation of the hull has worked good on my sanger flat. straight edge from under the boat towards the plate, turned each buckle accordingly. For years I had it set as a flat plate with slight tapers at the corners. Always was jumping all over the place at full throttle.

norcal73

 

[Rattle Can Lou]

I cut and saved this as a document becasue tit was such great detail..hope it helps.

Originally Posted by Hi Tech Marine
I'll try and make this as simple as possible. Keep in mind, this is ONLY a guideline. Not all boats like the same setup. It depends on the bottom, horsepower AND the installation setup. Like Bob aka "Fiat" stated, start with a straight edge at least 30" long. Take a 3-6" piece of 1/4" keystock and clamp it it the very back edge of the plate with a vise grip clamp, leaveing access to the area behind the far right plate boss. Protect the top side of the plate with a non coragated piece of cardboard or what ever. Place the straight edge against the bottom of the boat approx 6" forward of the recess. Adjust the plate up or down to just touch the keystock. Do the same for the left turnbuckle on the right plate. Now double check the right. If you have a TR1 or Hondo 511 with 3 turnbukles, do not set the center the same. I like to split the difference by putting about 1/8" gullwing in the plate (side to side). Now go to the left plate and do the same. The center plate is done by adjusting the outer turnbuckles the same and the adjust the center turnbuckles with the staightedge across the width till the plate is flat. Then double check the outer turnbuckles on the center plate again, re-adjust if it changed. Sometimes if the plate is way out of adjustment and you have to turn the turnbuckle alot, it will change your setting on the outside. Always go over it twice. From the 1/4" setting you can go up or down according to all your other variables. Driver experience, horsepower, setup... If you are unsure, it's best to set it 3 flats down from 1/4". Now here is where it gets tricky. If the bottom has never been done (or done by someone that's not as good as he thinks) the area 6" forward of the recess MAY not be flat! If this is the case... split the difference the best you can and spend a little more time with it at the lake to see what makes you happy. Good Luck, Jim

 

[Sangster~bbc]

cav. plate

well thanx for all the help guyshandhand, theres not allot of flat -v-drives around my neck of the woods just gay jets and eggbeaters haha well atleast im keeping it real in alberta
im going out to adjust the plate now, i plan on taking her out tomarow will let u now how she flys. I think i had her set pretty close but she would start dancing around site to side at about 70-85mph rangedevil

 

[stix818]

well thanx for all the help guyshandhand, theres not allot of flat -v-drives around my neck of the woods just gay jets and eggbeaters haha well atleast im keeping it real in alberta
im going out to adjust the plate now, i plan on taking her out tomarow will let u now how she flys. I think i had her set pretty close but she would start dancing around site to side at about 70-85mph rangedevil

Good luck and have fun!!! With my experience driving my uncle's 69 Sanger it was a wild ride at 100!!!

 

[jockorace]

Sangster,
I've owned several Sanger flats (last 2 were '72 gullwings) over the years. I agree with NorCal 73 in setting the plates as a flush extension of the bottom running surface, however I've then always tabbed the right side down 1/8" to compensate for the torque trying to 'twist' the boat down on the right side on the leave. Keep it simple and use this procedure.
You also said the boat was bouncing around (assume porpoising) from 70-85 mph. I assume 85 was your top speed. This too is very common on lake flats that top out at that speed. You're essentially out of HP at that point and the motor just cannot 'carry the boat' in a flat set any longer. My experience has been that when you UP the horsepower to run near or above a true 100 mph the boat (Sanger's anyway) will stay set and run flat.
Not to disregard what RCL posted about setting plates on later runner bottoms (with rocker in the bottoms), but those boats are entirely different than the older true flatbottoms. Hope I've helped some. Jocko

 

[poncho]

All the crap i wade through on these sites (dont mean that in a bad way) this thread has some good info, thanks for sharing guys. Best part was no one answered his question with some smart ass comment.
Thanks folks.

 

[392 cruiser]

also make sure your cavatation rod has at least two supports so it does not flex,once you hit that high speed the rod will actually flex around causing the plate to move up or down


thats my ten cents my 2 cents is free

 

[Sangster~bbc]

thanx for all the help guysdevildevil
i adjusted the plate so it was the same angle as the hall carrying the hulls angle all the way should i set the outsides down alittle! the outside of the hall kinda drops to the side alittle or just keep the same angle as the centre, my plate is a one peace and i have 8 rods and i am using a up and down pedal and if i dont hold the down pedal all the way the hole time she will jump all over the place anyway thanx for all the help and tips wish there were more of us down her instead of eggbeaters on pickleforks and cougar bubble decks with jets ow well atleast i have easy pickings haha

 

[sanger buzz]

Man, Poncho said it all ! Thanks

 

[schiada flatty]

sangsters boat has at least 2 cavitation rod supports but no springs in place. when i was out with him he is on the down peddal all the time. is that normal or would springs eliminate that some?

 

[Jetboatguru]

Sangster,
I've owned several Sanger flats (last 2 were '72 gullwings) over the years. I agree with NorCal 73 in setting the plates as a flush extension of the bottom running surface, however I've then always tabbed the right side down 1/8" to compensate for the torque trying to 'twist' the boat down on the right side on the leave. Keep it simple and use this procedure.
You also said the boat was bouncing around (assume porpoising) from 70-85 mph. I assume 85 was your top speed. This too is very common on lake flats that top out at that speed. You're essentially out of HP at that point and the motor just cannot 'carry the boat' in a flat set any longer. My experience has been that when you UP the horsepower to run near or above a true 100 mph the boat (Sanger's anyway) will stay set and run flat.
Not to disregard what RCL posted about setting plates on later runner bottoms (with rocker in the bottoms), but those boats are entirely different than the older true flatbottoms. Hope I've helped some. Jocko

sangsters boat has at least 2 cavitation rod supports but no springs in place. when i was out with him he is on the down peddal all the time. is that normal or would springs eliminate that some?

Read what Jocko posted. The boat HAS TO HAVE enough power to carry the nose of the boat. Otherwise here is what happens.

The boat is trying to carry the nose
It gets to the point where it runs out of hp to keep the nose up and it drops.
Then it thinks it can carry the nose again and it picks it up again
Then it runs out of power and drops it again
Then it thinks it can carry the nose and picks it up again
Then it runs out of power and drops the nose again
Then it thinks it has enough power to carry the nose and it picks it up again
Then it runs out of power and drops the nose again.
Rinse, lather, repeat!!

All this creating the "hopping" that he is experiencing.

It needs the pressure on the down pedal to keep it from trying to come up in the hop. Some things you will never get rid of until you pour more hp to it.

By adding springs, you will only keep the plates from sucking down. It may help a very small amount but all it will do is MAYBE make the hops a tiny but smaller because the plates wont be sucking.

 

[Homez]

So when you bought a ski flat from Sanger new in 1970 with mild horsepower
you got a porpeising boat that couldn't be cured ?

 

[Homez]

So Tony says Sanger ripped people off!

 

[jockorace]

Thanks Tony, I don't think it can be explained any clearer.
A couple of points though;
1) Schiada Flatty said Sangsters boat had NO pedal return springs????? It certainly should have one spring and a neutral position stop on the rod.

2) In response to Homey's comment.....ALL of those old 60's & 70's low powered flats porpoised, not just Sangers. (believe me, I've been driving them since 1962). If you had any brand flat that ran 65 or 70 mph freed up and porpoising, and would only run 62 mph with enough pedal to settle it down, no brainer..... let it porpoise and go a little faster! Homez, look at the boat in your Avatar.....it's doing exactly what we're describing!

3) Sangster, to answer your last question...only tab the right side down 1/8".

Jocko

 

[Homez]

Thanks Tony, I don't think it can be explained any clearer.
A couple of points though;
1) Schiada Flatty said Sangsters boat had NO pedal return springs????? It certainly should have one spring and a neutral position stop on the rod.

2) In response to Homey's comment.....ALL of those old 60's & 70's low powered flats porpoised, not just Sangers. (believe me, I've been driving them since 1962). If you had any brand flat that ran 65 or 70 mph freed up and porpoising, and would only run 62 mph with enough pedal to settle it down, no brainer..... let it porpoise and go a little faster! Homez, look at the boat in your Avatar.....it's doing exactly what we're describing!

3) Sangster, to answer your last question...only tab the right side down 1/8".

Jocko

gotcha -tryin to stir the pot with
"the Man". We have some very old footage of the boat in my avatar 8mm put on video. Thats my Dad- all the boats at the drags porpised thier way down the 1/4- Ray Casselli is credited for inventing the adjustable cav plate that ended that...

 

[jockorace]

That's a cool picture of your Dad!

Here's a funny 'back in the day' (early 60's) story.
My Dad's family ski flatbottom (16' Glen L) didn't have an adjustable cav plate, so my Dad kept it tabbed down so it would ride smooth for all of us water skiing kids. The funny part was he could not figure out why I could drive the boat (14 yrs old) and beat other boats that beat him when he drove it. I told him it was cuz he weighed 250 and I weighed 125. What I didn't tell him was that I always pulled around the point at Will-o-Point in Lakeport and adjusted all of the turnbuckles way up to pick up about 5 mph, just enough to beat some of these guys and porpoising like crazy. Granted, we were only running maybe 65 mph, but to me at 14 yrs old it was the evening Nationals!
Jocko

 

[Sangster~bbc]

alright thanx for all the tips and infohand....I set her up yesterday and she seems to be going straight and not porpoising anymore must of had the plate set to far down, and my boat has a left hand rotating prop so i set the drivers side down alittle left side....anyway thanx for all the tips and helpdevildevil: