Heat Gurus: Question regarding mid-frame heat deflectors
Thread Starter
|
Intermediate
Joined: Jul 2013
Posts: 47
Likes: 0
From: Salt Lake City
Heat Gurus: Question regarding mid-frame heat deflectors
Do the mid-frame heat deflectors have any impact on engine cooling? I know they deflect heat from the rider, but do they hurt or help the engine's cooling ability?
Since I've done the de-Cat and installed Wards Part Werks FSC fans the bike is way cooler - cool enough that I do not need the heat deflectors. But, I don't want to remove the deflectors if they promote cooling. On the other hand - I do want them gone if they don't.
Opinions? Thanks.
Bill
Since I've done the de-Cat and installed Wards Part Werks FSC fans the bike is way cooler - cool enough that I do not need the heat deflectors. But, I don't want to remove the deflectors if they promote cooling. On the other hand - I do want them gone if they don't.
Opinions? Thanks.
Bill
That is a good question.
It seems to me (I have NO empirical evidence) that it keeps the heat off the rider, while at the same time scooping the air from the sides toward the back of the rear cylinder.
Since it does not have a clear exit path there (down or back), it seems that the two air streams will collide and ??? not having an easy path of exit.
I thought about removing both of them, but then thought the scoop actually pulls air in to the space behind the rear cylinder.
What I did was remove one of them.
This leaves one to scoop air from the side, the air rushing past the back of the rear cylinder and easily exiting the other side.
I have no rider heat discomfort, so leaving them on, taking them off, no difference to me. I did this because it seem to make sense that it would cool the rear cylinder better.
What I should probably do is put it back on, take a run, measure with the IR gun, then remove one and take the exact same run and measure again with the IR gun.
Tank lifts do make a difference, getting that tank up off the rocker covers is good for 10-20 degree reduction. But the tank sits much closer to the engine, trapping the heat and blocking air flow.
I want a wind tunnel!
It seems to me (I have NO empirical evidence) that it keeps the heat off the rider, while at the same time scooping the air from the sides toward the back of the rear cylinder.
Since it does not have a clear exit path there (down or back), it seems that the two air streams will collide and ??? not having an easy path of exit.
I thought about removing both of them, but then thought the scoop actually pulls air in to the space behind the rear cylinder.
What I did was remove one of them.
This leaves one to scoop air from the side, the air rushing past the back of the rear cylinder and easily exiting the other side.
I have no rider heat discomfort, so leaving them on, taking them off, no difference to me. I did this because it seem to make sense that it would cool the rear cylinder better.
What I should probably do is put it back on, take a run, measure with the IR gun, then remove one and take the exact same run and measure again with the IR gun.
Tank lifts do make a difference, getting that tank up off the rocker covers is good for 10-20 degree reduction. But the tank sits much closer to the engine, trapping the heat and blocking air flow.
I want a wind tunnel!
__________________
DKCustomProducts.com
DKCustomProducts.com
Road Captain
Joined: Sep 2007
Posts: 555
Likes: 9
From: Billings, Montana
That was the reason I put the scoop under the front forks back on my trike. I didn't want that air coming over the top of the tank wasted and wanted it pushed down over the engine. DK makes a bracket to do this. I made my own. Took two small pieces of metal and drilled two holes in each. One hole to mount it to the trike and on hole to mount to the scoop so that it clears the shock. I also think there is plenty of room for the air from the sides to go under the seat and out the back and helps cool the rear cylinder.
Club Member
Joined: Aug 2007
Posts: 10,393
Likes: 2,060
From: N. Atlanta Burbs
The stock Harley mid frame deflectors scoop air and force it to vent through the frame opening just under the seat. The hot scooped air circulates under the seat and out the rear part of the body just behind the passenger seat. This is a restricted air flow if you take a visual and follow the path.
The force venting takes the super heated air and passes it across your battery and ECM. That's not good. The ECM is a computer. How well does a hot computer operate?
The same air will circulate under your seat. Fine in the winter time for extra seat of the pants comfort but not so good during the summer months.
Removing them is not a good option either. Not all trikes have modifications for tuning or cams, they run stock configurations and need the rising heat protection to the rider even though the stock deflectors are a deterrent to the electronics longevity and operation.
Captain Itch makes the Crotch Cooler, RJ makes the original No More Fried Thighs, both are sponsors of the site.
The Crotch Cooler is a leather product that lays/droops under the seat and just over the top of the rear cylinder head. It gives more protection to the riders leg than it does for any recorded motor temp relief but it does eliminate some the forced hot air under the seat.
The No More Fried Thighs is a more firm and molded product which is designed to take the super heated air from the rear cylinder while in motion and whisk it away to the outside rear of the bike/trike.
Both products are well crafted handmade products.
If you look at the sticky at the top of the TG forum you will read in my ABC thread the actual heat reduction using the No More Fried Thighs product found in the heat removal project. The actual reduction to the rider was 19*F if memory serves. I still use this product on my TG. Wife has the Crotch Cooler on her Heritage.
The force venting takes the super heated air and passes it across your battery and ECM. That's not good. The ECM is a computer. How well does a hot computer operate?
The same air will circulate under your seat. Fine in the winter time for extra seat of the pants comfort but not so good during the summer months.
Removing them is not a good option either. Not all trikes have modifications for tuning or cams, they run stock configurations and need the rising heat protection to the rider even though the stock deflectors are a deterrent to the electronics longevity and operation.
Captain Itch makes the Crotch Cooler, RJ makes the original No More Fried Thighs, both are sponsors of the site.
The Crotch Cooler is a leather product that lays/droops under the seat and just over the top of the rear cylinder head. It gives more protection to the riders leg than it does for any recorded motor temp relief but it does eliminate some the forced hot air under the seat.
The No More Fried Thighs is a more firm and molded product which is designed to take the super heated air from the rear cylinder while in motion and whisk it away to the outside rear of the bike/trike.
Both products are well crafted handmade products.
If you look at the sticky at the top of the TG forum you will read in my ABC thread the actual heat reduction using the No More Fried Thighs product found in the heat removal project. The actual reduction to the rider was 19*F if memory serves. I still use this product on my TG. Wife has the Crotch Cooler on her Heritage.
The stock Harley mid frame deflectors scoop air and force it to vent through the frame opening just under the seat. The hot scooped air circulates under the seat and out the rear part of the body just behind the passenger seat. This is a restricted air flow if you take a visual and follow the path.
The force venting takes the super heated air and passes it across your battery and ECM. That's not good. The ECM is a computer. How well does a hot computer operate?
The same air will circulate under your seat. Fine in the winter time for extra seat of the pants comfort but not so good during the summer months.
Removing them is not a good option either. Not all trikes have modifications for tuning or cams, they run stock configurations and need the rising heat protection to the rider even though the stock deflectors are a deterrent to the electronics longevity and operation.
Captain Itch makes the Crotch Cooler, RJ makes the original No More Fried Thighs, both are sponsors of the site.
The Crotch Cooler is a leather product that lays/droops under the seat and just over the top of the rear cylinder head. It gives more protection to the riders leg than it does for any recorded motor temp relief but it does eliminate some the forced hot air under the seat.
The No More Fried Thighs is a more firm and molded product which is designed to take the super heated air from the rear cylinder while in motion and whisk it away to the outside rear of the bike/trike.
Both products are well crafted handmade products.
If you look at the sticky at the top of the TG forum you will read in my ABC thread the actual heat reduction using the No More Fried Thighs product found in the heat removal project. The actual reduction to the rider was 19*F if memory serves. I still use this product on my TG. Wife has the Crotch Cooler on her Heritage.
The force venting takes the super heated air and passes it across your battery and ECM. That's not good. The ECM is a computer. How well does a hot computer operate?
The same air will circulate under your seat. Fine in the winter time for extra seat of the pants comfort but not so good during the summer months.
Removing them is not a good option either. Not all trikes have modifications for tuning or cams, they run stock configurations and need the rising heat protection to the rider even though the stock deflectors are a deterrent to the electronics longevity and operation.
Captain Itch makes the Crotch Cooler, RJ makes the original No More Fried Thighs, both are sponsors of the site.
The Crotch Cooler is a leather product that lays/droops under the seat and just over the top of the rear cylinder head. It gives more protection to the riders leg than it does for any recorded motor temp relief but it does eliminate some the forced hot air under the seat.
The No More Fried Thighs is a more firm and molded product which is designed to take the super heated air from the rear cylinder while in motion and whisk it away to the outside rear of the bike/trike.
Both products are well crafted handmade products.
If you look at the sticky at the top of the TG forum you will read in my ABC thread the actual heat reduction using the No More Fried Thighs product found in the heat removal project. The actual reduction to the rider was 19*F if memory serves. I still use this product on my TG. Wife has the Crotch Cooler on her Heritage.
Question the OP had, and I have...
If one is not concerned with rider felt heat, would removing the deflectors (or one deflector), and NOT replacing them with another brand, result in any reduction in engine temps (not felt heat by rider, but actual engine temps)?
Would like to hear any thoughts or experience with that.
Trending Topics
Club Member
Joined: Aug 2007
Posts: 10,393
Likes: 2,060
From: N. Atlanta Burbs
Great info. I remember reading about the rider felt heat reduction on the No More Fried Thighs product a couple of years ago in your post/study.
Question the OP had, and I have...
If one is not concerned with rider felt heat, would removing the deflectors (or one deflector), and NOT replacing them with another brand, result in any reduction in engine temps (not felt heat by rider, but actual engine temps)?
Would like to hear any thoughts or experience with that.
Question the OP had, and I have...
If one is not concerned with rider felt heat, would removing the deflectors (or one deflector), and NOT replacing them with another brand, result in any reduction in engine temps (not felt heat by rider, but actual engine temps)?
Would like to hear any thoughts or experience with that.
Here's another trick to see how much heat is actually being packed under your seat with the stock scoops.
Remove your seat. Install an all thread rod in place of the seat screw. Put a nut on the all thread with a washer about an inch above the fender. Put two blocks, about an inch thick, under the rear of the seat. Install another nut and washer on the all thread. What this will do is raise the seat up so the air passage will free flow.
While riding you will find the seat will get HOT and if you have a temp sensor just behind the seat you will find it shoot up in temp pretty good. The air flow behind the seat will be a huge consistent gust of wind comparable to your riding speed. It will not reduce your motor heat but it's a great place for the hot air to go if you can stand the seat temps.
Do that to see just how much flow you can increase over the rear cylinder. You will be amazed.
For these reasons I use the RJ's on my trike. Doesn't stack hot air under the seat and will keep the hot air moving. It will create a whisk effect down low on the rear of the trike and under the legs of your passenger instead of directly on them. If you move the hot air off the cylinder and off of the rider(s) then you have reduced your motor heat while not inconveniencing the riders.
No product is perfect, with that being said... no one will be 100% happy until they too find a product that works best for them. Compromise is the key here.
Wards fans are the cat's ****. Buy'm, install'm and enjoy.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Thread Starter
|
Intermediate
Joined: Jul 2013
Posts: 47
Likes: 0
From: Salt Lake City
Intuitively, removing one of the deflectors to gain more air flow to the rear cylinder makes sense. For, you'd want unequal air pressure to move hot air out. Having said that, without temp sensors and an air tunnel - we may never know. What sounds right does not always work. But I'll probably try it to see how it feels (literally).
I can not say enough good things about Ward's FCS fans. Combined with the de-Cat, they've lowered temps enough I'm willing to experiment with removing the heat deflectors. That says something - the difference is that significant.
I initially thought I'd have some heat issues on the right side since the fans blow through the heads in that direction. In fact, if I hold my hand on the right side of the engine with it hot and the fans on there's a very hot stream of air coming from the rear cylinder head. From the front cylinder - not as hot.
Anyway, it seems the velocity of that hot air is enough that it blows out away from the bike when at a light and not up onto my right thigh. Yes, the right side still feels hotter than the left (the pipes are there, after all) - but not what one would expect.
I'm doing what Jason recommends with the FCS fans - running them if the engine is running and for about 5 minutes after a shut down. I agree with Jason's stance that 1) you beat high heat if you never let it build to begin with and 2) it's healthier for the fans to cool themselves - or else they're sitting there baking if not on.
Bill
I can not say enough good things about Ward's FCS fans. Combined with the de-Cat, they've lowered temps enough I'm willing to experiment with removing the heat deflectors. That says something - the difference is that significant.
I initially thought I'd have some heat issues on the right side since the fans blow through the heads in that direction. In fact, if I hold my hand on the right side of the engine with it hot and the fans on there's a very hot stream of air coming from the rear cylinder head. From the front cylinder - not as hot.
Anyway, it seems the velocity of that hot air is enough that it blows out away from the bike when at a light and not up onto my right thigh. Yes, the right side still feels hotter than the left (the pipes are there, after all) - but not what one would expect.
I'm doing what Jason recommends with the FCS fans - running them if the engine is running and for about 5 minutes after a shut down. I agree with Jason's stance that 1) you beat high heat if you never let it build to begin with and 2) it's healthier for the fans to cool themselves - or else they're sitting there baking if not on.
Bill
Last edited by UTES; Aug 9, 2013 at 05:59 PM.
Stage III
Joined: Jul 2013
Posts: 3
Likes: 0
From: Atlanta, GA
Help. The ABC article did not say anything about fans on the engine. It seems that
the fans are recommended to help with the heat? Purchased 2013 TG in April (my first Harley) and found the heat to be too much. Read and joined the forum looking for a solution I could afford. Stage 1 next year if I can afford it. Until then will the fans help to the point that I can ride this summer? I installed the RJ originals which
has helped. As you can see this is my first post after reading forums since since buying the trike. Any help is welcomed.
Baines
the fans are recommended to help with the heat? Purchased 2013 TG in April (my first Harley) and found the heat to be too much. Read and joined the forum looking for a solution I could afford. Stage 1 next year if I can afford it. Until then will the fans help to the point that I can ride this summer? I installed the RJ originals which
has helped. As you can see this is my first post after reading forums since since buying the trike. Any help is welcomed.
Baines