The International Cessna^® 170 Association

I will be installing new Airforms baffles on my 51 A model. Looking for advice or any particular problems, difficulties and shortcuts from those that have done this. Thanks in advance....Ray

They are a good fit

Thanks...

wingnut170 wrote:I will be installing new Airforms baffles on my 51 A model. Looking for advice or any particular problems, difficulties and shortcuts from those that have done this. Thanks in advance....Ray

Can I request that you post pictures here at least of the final install (a documentation of the process would be even better)?
Thanks!!
Doug

The only issue I had when I installed mine in 2006 was that I had to elongate the holes in the sump baffle where the bolts for the intake manifold go. This is on a later B-model, and I’m not sure of any differences there my be on the earlier models in that area.

dstates wrote:

wingnut170 wrote:I will be installing new Airforms baffles on my 51 A model. Looking for advice or any particular problems, difficulties and shortcuts from those that have done this. Thanks in advance....Ray

Can I request that you post pictures here at least of the final install (a documentation of the process would be even better)?
Thanks!!
Doug

Yes, I will do my best.

cessna170bdriver wrote:The only issue I had when I installed mine in 2006 was that I had to elongate the holes in the sump baffle where the bolts for the intake manifold go. This is on a later B-model, and I’m not sure of any differences there my be on the earlier models in that area.

Thanks....

I have a 51 A model also, and purchased a complete engine baffle kit from Airforms. Mine did not fit. The top baffle was too tall in the front to fit under the cowl. A call to Airforms resulted in a replacement that was shorter but still too tall, and the curved top/side baffles wouldn't fit at all.

I hope you've had better luck. If you have, photos would be appreciated. I'm still trying to figure out how to resolve this with Airforms.

I had Airforms baffles installed during my overhaul in 2018 on my 52 B model. The work was done by Stick-n-Rudder at Chatham Airport in MA. Long story short is the shop had to go back and forth several times with Airforms and do several custom adjustments. The shop owner who does a lot of Cessna work said he was surprised they didn’t fit better. I’m away from the Mx logs right now but If I recall correctly they sent sketches and measurements back and forth trying to get the fit correct.

Hope it goes better for you. I can send install photos next week sometime.

John Briggs’ new baffles don’t look right at all, Airforms has done better in the past. Some better pictures would help identify the problems.

The picture is my Airforms baffles. They used my original baffles to make their patterns but something has changed.

John from the head of the "for what it is worth department", in the picture your nose bowl appears to be low, the center line of the spinner is not in line with the center of the cowl cooling openings.

Speaking on the trend of baffling, Do you guys know if rather than using the dog house style on an a model you might be able to use a 172a model baffling that would rely on the cowling for the top?

abushey123 wrote:Speaking on the trend of baffling, Do you guys know if rather than using the dog house style on an a model you might be able to use a 172a model baffling that would rely on the cowling for the top?

The 172A has a very different latching system for the cowl. I believe it would be necessary to adopt the entire upper/lower cowl, as well as the complete interior baffling (getting rid of the “dog house” baffling of the earlier models.)

The “pressure cowl” first appeared on the 1953 B-model, which also introduced improved cabin heating, and mid-way thru the model year, also introduced the “lady legs” landing gear with improved damping/handling (in the view of many.)

Personally I doubt it's worth the effort to switch from the doghouse plenum style baffling. That being said, if one were looking for "acceptable data" for a field approval to use the existing cowl together with the '53 and later style baffling, the L-19 might be an example to show that this combination has been used by Cessna.

1951 C170A cowl fitment using Airforms baffles.

In the last picture, it can be seen that in years past, attempts have been made to relieve the upper cowl stringers to keep them from bearing down onto and wearing grooves into the airbox center section due to “cowl sag”. All of those attempts have failed due to the flexibility of the upper cowling and the vertical downward air loading due to the shape of the cowl. It’s my opinion the downward force on the upper cowl is also a major factor in the common lower firewall cracking problem at the bottom cowl/firewall screw. The downward air load force is reacted in the lowest cowl/firewall screw (note triangle patch on the firewall side at the bottom cowl screw).

What finally stopped the contact between the upper cowl stringers and the airbox center section was the addition of teflon wear blocks mounted on Monadnock fasteners attached to the airbox center support structure with the teflon blocks bearing on the upper cowl stringers. This has worked very well for the past few years.