2011+ 310/320 Engine Hatch Question

TonyG13

I'm planning on replacing my sound deadening / heat shield on the engine hatch this winter.

Can I raise the engine hatch to its limit, then pull the cotter pin out and manually open the hatch all the way back to a 90 degree angle (resting on the back seat)? If so, any special considerations I need to worry about?

Also, has anyone else replaced the heat/sound shield - and what did you use?

LaRea

I'm planning to do mine.  Haven't decided whether to remove and replace, or simply add another 1/4" layer on top of the existing one.  

Take a look at Soundown products, like this:

https://www.jamestowndistributors.com/product/product-detail/11868

LaRea

You'd get better sound performance from this one, which has a mass layer sandwiched between two layers of foam.  

https://www.jamestowndistributors.com/product/product-detail/9345

TonyG13

Those are some of the options I was considering. I was also thinking about this product...

https://www.fisheriessupply.com/soundtec-sound-insulation-vinyl-foam-barrier-composite

Mine is starting to fall away from the decking, so tomorrow I was going to take it off then I'd get a better idea of what to use.

Still wondering about opening the hatch to the full 90 degrees by pulling the pin.

LaRea

Looks similar.  The key is the mass layer in the middle.  

On the 342 and the 370, you can open the hatch 90 degrees by pulling the pin.  It's required if removing the engines, and I'd guess they are all built that way.  

Pat310

@TonyG13 I made an extension for my hatch lift from 3/4” heavy wall conduit.  I made mine 14” and it gets me to about 70 degrees open. And it’s much safer then trying to handle that heavy hatch by hand. Open hatch, prop it up, disconnect top pin, retract lift, add extension. Open the rest of the way. 

Handymans342

You can open all the way but use some type of padding to protect everything 

TonyG13

Thanks Handy. I saw that in one of your earlier posts. I think I have some 3/4" conduit laying around the garage. I'll give it try.

reneechris14

When I did my 342 the back of the hatch hit one of the snaps and chipped the gel coat very little. You need to be able to brace it some how 🤔 

TonyG13

@Handymans342 - You are right! That hatch is a sucker to lift. I think I'll wait until I have some help - and proper propping gear.

On a side note, I took off the insulation which was basically 1/2 foam with a metallic heat shield. Almost exactly like the one from Jamestown...

https://www.jamestowndistributors.com/product/product-detail/11868

I think I may look around for something more robust like the others we mentioned.

After I took the foam off I noticed a huge hole (~5") in the starboard aft portion of the hatch...



...looks like it goes up into the inside portion of the seat. Definitely not visible from above. Anybody know its purpose in life?

bella-vita

I had a bud make a Extension out of aluminum pipe I also had to make the adapter for the top when I installed new ram 

davidbrooks

@TonyG13 that is supposed to be a vent. Blowers suck air out. You need one or more to let air in. My 342 has two. Should have a grate on it and a small section of hose on it.

TonyG13

Interesting. It was definitely covered by the insulation - and the install looked OEM. I don't think it was replaced prior since it's only six years old. And from what I can tell it's just the under side of the back seat shell. Where would it pull air from the outside? You don't happen to have a pic of what yours looks like?

Handymans342

You can get that black foam called Armorflex. We use it in the HVAC industry. 3x5 sheets. Then buy some of the foil wrap which comes in a roll. Glue it on and then paint on the white vapor barrier coating

aero3113

@TonyG13 , here’s what mine look like on my 330. Do you have one on the port side also?

TonyG13

No. Just one big hole on the starboard side as shown. I don't have any pics - will try and get some tomorrow, but from memory I think my vents route differently.

Anybody with a late model 310/320 have a hose going to that hole?

Handymans342

No, they only use the gunnel vent holes

aero3113

On my boat the gunnel vents are for the blowers. The vents on the hatch are just hoses, no blowers.

TonyG13

Thanks Handy. Also taking a look at your ArmorFlex recommendation.

TonyG13

@aero3113 - So by the looks of your pic they just allow fresh air down via gravity to the bottom/mid of the bilge?

aero3113

Correct @TonyG13 , or it gives some air flow up into my rear seat storage and transom locker.

LaRea

TonyG13 said:

@aero3113 - So by the looks of your pic they just allow fresh air down via gravity to the bottom/mid of the bilge?

Not gravity -- forced induction.  The blowers pull air from the bottom of the bilge, and it's replaced by air that has to come from somewhere.  You don't want the system to pull [blower] exhaust back into the bilge.  So you provide a separate intake path that's not contaminated by blower exhaust.

LaRea

This is important:  the blowers aren't just fans.  They are part of an integrated fire suppression *system*.  They are carefully designed to work together with the intake hoses, exhaust hoses, halon tank and automatic cutoff (which turns off the blowers to avoid feeding the fire with fresh oxygen). 

@Handymans342 started a great thread about this a few years ago.  It helped educate a lot of us, including me.  

Handymans342

LaRea said:

This is important:  the blowers aren't just fans.  They are part of an integrated fire suppression *system*.  They are carefully designed to work together with the intake hoses, exhaust hoses, halon tank and automatic cutoff (which turns off the blowers to avoid feeding the fire with fresh oxygen). 

@Handymans342 started a great thread about this a few years ago.  It helped educate a lot of us, including me.  

Post the link for all the people that didn’t read it

LaRea

Was it on the old forum?  I can't find it.  

Handymans342

LaRea said:

Was it on the old forum?  I can't find it.  

No, new one.