Author Topic: Better engine mounts for CVX-20s (And other Glastrons)  (Read 306 times)

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Offline cvxjet

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Better engine mounts for CVX-20s (And other Glastrons)
« on: November 15, 2020, 05:23:13 PM »
Before getting to this subject, I just want to say...If you read this and have either a better idea or something to suggest, please do...I have a bruise on my forehead from slapping it when someone has looked at my "Great ideas" and then suggested something simpler/better- I need to keep that bruise going because it is my signature look!

When I had my engine rebuilt the first time in 2003, I installed a full-length 10-QT Milodon oil pan because I don't like the front sump Ford pans...They are not so bad in a car (At least an above 13 second car) but in a jet boat you have good-to-great acceleration coupled with some bow rise- this can starve the engine for oil under acceleration.

(Note; I have seen bad reviews for the Milodon pan, but mine fit well and has worked great for 17 years...There are other options, including Canton) I also used the late-model all rubber one-piece gasket- I had to drill out the corner holes for the older larger bolts; Two pieces of 1/4" aluminum plate, drilled for the larger size, plus two holes for clamp bolts- then clamp this fixture (Tightly!) on the gasket to keep the metal bushing INSIDE the gasket from spinning while you drill it out to the larger size)

The problem with a full-length oil pan is that the engine mount set-up for Berkeley Jets has a crossmember that will interfere with the pan. If you only cut it out then this will put more stress on your stringers. I have designed a solution- actually two solutions that really improve the strength of the whole setup.

First up was clearing the pan- that crossmember had to go but I wanted to still have a cross-brace. I picked up a piece of 1/4" steel that would fit between the front and back verticals of the engine mount bracket, then curved it so that it would start at one side, curve under (The oil pan) and then come up the other side (See Diagram). It was not as rigid as the (vertical) original crossmember but better than no cross-brace. After having the piece welded in I cut out the old brace.

This worked for 3 years just fine.....But when I needed the engine rebuilt again (Bad head work when I had a "Friend" port the heads which caused a valve to seize out in the Delta(10 miles home on 1 cylinder bank) I decided to up the ante!

A lot of hot boats are converted to a "Rail mount" engine mounting setup. You bolt a long piece of aluminum angle to the stringers, then cross-members at the front and back of the engine tie together to make a rigid mounting that can handle any amount of power.

But the CVX-20s have a floor on top of the stringers which limit the amount of stringer that is accessible for such a system.....I had to think about this; Gears grinding....smoke out of ears......And a new idea came into being- a Mini-rail system!

I picked up some 1/4" thick angle iron and cut it to fit on TOP of the stringer in that small exposed section, then I used more angle iron to replace the 90* pieces that go between the crossmember and the stringers(Rails) Critical to good strength and rigidity of the setup was that instead of SLOTTED adjustable holes (To fit multiple boats) I drilled the holes in the 90s to exactly fit my engine mount dimensions- so now it is rigid....even if the bolts were a little loose there is no flex or play in the set-up(And no twisting force applied to the stringers).

When I mounted those rails on top of the stringers I mixed up some resin with micro-balloons and cut fibers to make a putty that I put between the top of the stringer and the bottom of the top of the rail- that way the weight load is spread evenly on the stringer (Most of the resin-putty will squeeze out but what's left will even the surface out). I also used the original little plates that were on the bolts thru the stringers; The stringers and fiberglass had taken a set during the manufacturing process so the little plates fit- trying to make it smooth would have taken a lot more work...although it is not particularly pretty, I defy you to find someone who will stand on their head in the engine compartment with a flashlight clenched in their teeth to see those little metal plates!