Cyl temp riser blocker baffle

[Bob_pipedream]

Hi all,

Trying to even out my CHTs - standard issue of numbers 1 and 2 being too cool...

I have looked everywhere in the forum and google for details of the temp risers or what some call blockers that are installed on these cylinders, but can not find any pictures. I want to put them in Sunday morning - would anyone have a link or pictures of some temp blockers? I understand that they are on RV9 baffle plans.

Thanks,

Bob

[Andy Hill]

Bob...

They are on the baffle plans - no need for plans, just a, say, 1" strip of AL.

We are planning to fit some on our RV-8 As an interim measure, we put some speed tape over the #2 cylinder... and, errr, 3 years / 370hrs later, it's errr, still there working well

Andy

[N941WR]

Bob,

I’ve always called those things “air dams”, try doing a search on that.

Go to your local big box hardware store and pick up some metal tape. I don’t know what the correct name of the stuff is but it comes in rolls and is truly made of metal, either aluminum or stainless steel, I'm not sure which.

Use that on your front two cylinders until you figure out the size and shape you need.

As for making the baffles, I recommend putting in flush rivets and plate nuts on the baffles in front of #1 & #2 cylinders. That way you can make your air dams any size you need and change them out as the OATs rise in the spring and drop in the fall.

BTW, you will se a number of RV's flying with just the tape.

[N941WR]

It is called Aluminum Foil Tape.

[scard]

Originally Posted by N941WR

Bob,

I’ve always called those things “air dams”, try doing a search on that.

Go to your local big box hardware store and pick up some metal tape. I don’t know what the correct name of the stuff is but it comes in rolls and is truly made of metal, either aluminum or stainless steel, I'm not sure which.

Use that on your front two cylinders until you figure out the size and shape you need.

As for making the baffles, I recommend putting in flush rivets and plate nuts on the baffles in front of #1 & #2 cylinders. That way you can make your air dams any size you need and change them out as the OATs rise in the spring and drop in the fall.

BTW, you will se a number of RV's flying with just the tape.

I concur completely. Tape and fly until you get tired of looking at the tape. Stick it right on the front face of the cylinders, only about 1.5 inch high to start with. The tape is in the heating and cooling/vent section of the local Home Depot. Oh, sorry, I missed the UK location... .

[Bob_pipedream]

Thanks all,

Ended up using a piece of 0.032" with four pop rivets making a curved ramp to the cylinder head. However, then I used aluminimum tape on the cylinder head fins - partially to protect the cyl head from the aluminimum ramp and partially as it is easy to adjust the tape up or down to adjust cooling. The ramp keeps the tape in position too.

Also blocked side of ramps in top cowl with foam and epoxy.

Had some good results (see my other thread on rough engine mixture rich) and oil temp went down by 30 degrees whilst CHT average went down by about 40 degrees (front cylinders dropped a bit , but rears really dropped - so must have smoothed airflows).