Latham Single Ram System Questions Relation to Handling
#1
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How much play normal is there in an actuator. Full hydraulic system to Helm. Moving drive with hand can get about an eight inch of squish with boat not running. Boat running and hydraulic system pressurized can induce the same movement. Tried bleeding air out at fittings attached to ram made no difference. Is there any other place to look to bleed to get this play out or is this inherent to the design?
Don't notice play under normal operation. Boat bow does want to wave back and forth under hard acceleration with increasing oscillations 4500 up to 5000 RPM if tried with neutral or slight trim. Does not feel like chine walk since there is no rolling sensation just bow wanting to move left to right under acceleration. Back it off to 4000 grand give boat full positive trim mash throttle and boat stays firmly seated on pad tracks straight never any hints of bow steer or chine walk. Can turn prop up past 5500 RPM in this condition runs like on rails. Is this issue related to the play in the Ram or inherent from lots of power stuffed in a small hull. Boat specifics 1989 Regal Velocity 230 designed by Steven Stepp. Hull bottom nearly same as 22 Velocity. Power 454SC 550 dyno HP into Bravo drive, 1.5 ratio, crescent nose cone, mirage three blade 27 pitch, no tabs. I owned a 22 Velocity several years back with 454 Mag and never experienced this bow steer or waving sensation. Did get it to chine walk a few times learning to drive it but was different sensation. Any handling thoughts? Is it play in the Ram under neutral or slight positive trim or is it the power and torque lifting the stern off the pad and bow wanting to catch? There is no other play present in the drive other than slight squish in external ram. Hinge pin bushing were replaced thinking this was source this removed play in in lower unit skeg. This did not affect condition. Since I now know the sensitivity relating to acceleration and how to avoid it with lots of positive trim it is not a big issue but would like to hear any body elses input.
Also fluid that came out when bleeding Latham ram is red in color. What is the correct fluid to replace it? Looks like Dexron II ATF fluid. PS fluid in engine mount PS pump is clear so separate reservoirs exist though power to latham pump comes from PS pump fluid. Any special fill procedures on the red fluid? Need to top off reservoir now but do not know the correct fluid.
Don't notice play under normal operation. Boat bow does want to wave back and forth under hard acceleration with increasing oscillations 4500 up to 5000 RPM if tried with neutral or slight trim. Does not feel like chine walk since there is no rolling sensation just bow wanting to move left to right under acceleration. Back it off to 4000 grand give boat full positive trim mash throttle and boat stays firmly seated on pad tracks straight never any hints of bow steer or chine walk. Can turn prop up past 5500 RPM in this condition runs like on rails. Is this issue related to the play in the Ram or inherent from lots of power stuffed in a small hull. Boat specifics 1989 Regal Velocity 230 designed by Steven Stepp. Hull bottom nearly same as 22 Velocity. Power 454SC 550 dyno HP into Bravo drive, 1.5 ratio, crescent nose cone, mirage three blade 27 pitch, no tabs. I owned a 22 Velocity several years back with 454 Mag and never experienced this bow steer or waving sensation. Did get it to chine walk a few times learning to drive it but was different sensation. Any handling thoughts? Is it play in the Ram under neutral or slight positive trim or is it the power and torque lifting the stern off the pad and bow wanting to catch? There is no other play present in the drive other than slight squish in external ram. Hinge pin bushing were replaced thinking this was source this removed play in in lower unit skeg. This did not affect condition. Since I now know the sensitivity relating to acceleration and how to avoid it with lots of positive trim it is not a big issue but would like to hear any body elses input.
Also fluid that came out when bleeding Latham ram is red in color. What is the correct fluid to replace it? Looks like Dexron II ATF fluid. PS fluid in engine mount PS pump is clear so separate reservoirs exist though power to latham pump comes from PS pump fluid. Any special fill procedures on the red fluid? Need to top off reservoir now but do not know the correct fluid.
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Vmax,
I have a twin-ram Latham setup, and I don't get ANY (none, zip, nada) side to side movement with it sitting on trailer, turned off. It definately sounds like you have air in the system.
I did a post for bleeding twin-ram, twin engine setups, most of this should apply.
http://www.offshoreonly.com/forums/s...threadid=49030
Steering and general stability is something worth looking into soon. ;-) Let me know if this works for you, or if you need any more info.
Good luck,
Brian
I have a twin-ram Latham setup, and I don't get ANY (none, zip, nada) side to side movement with it sitting on trailer, turned off. It definately sounds like you have air in the system.
I did a post for bleeding twin-ram, twin engine setups, most of this should apply.
http://www.offshoreonly.com/forums/s...threadid=49030
Steering and general stability is something worth looking into soon. ;-) Let me know if this works for you, or if you need any more info.
Good luck,
Brian
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Did you say eight inches of movement or an eighth of an inch?
Anyway, have you always had this problem? Have you changed anything recently that started it?
Other than the steering, the nose cone could be the culprit. Your x-dimension is probably fairly conservative, so the cone very well could be providing extra leverage on the outdrive causing the steering effect. This is common with nose cones installed on boats with low drive heights.
Anyway, have you always had this problem? Have you changed anything recently that started it?
Other than the steering, the nose cone could be the culprit. Your x-dimension is probably fairly conservative, so the cone very well could be providing extra leverage on the outdrive causing the steering effect. This is common with nose cones installed on boats with low drive heights.
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Originally posted by Ric232
Did you say eight inches of movement or an eighth of an inch?
Anyway, have you always had this problem? Have you changed anything recently that started it?
Other than the steering, the nose cone could be the culprit. Your x-dimension is probably fairly conservative, so the cone very well could be providing extra leverage on the outdrive causing the steering effect. This is common with nose cones installed on boats with low drive heights.
Did you say eight inches of movement or an eighth of an inch?
Anyway, have you always had this problem? Have you changed anything recently that started it?
Other than the steering, the nose cone could be the culprit. Your x-dimension is probably fairly conservative, so the cone very well could be providing extra leverage on the outdrive causing the steering effect. This is common with nose cones installed on boats with low drive heights.
I believe problem was inherent since I bought boat in July. Have done nothing but try to improve it.
The nose cone is quite large and was installed prior to purchase. The install job has several waves it iit. Plan to regrind, fill and regrind it smooth in spring to get it ready.
Where is the proper point to take an x dimension mesurement?
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