[mensajero]

URGENT, NEED OPINION LAST MINUTE PROBLEM

I send for a new Derale hose kit at Summit. I asked at Summit for their opinion. But looks like Professor Overdrive has a lot of work. Some time ago, I bought this thermal shield for the intake. I used some of it and this was a yard left over.

The oil Derale hose that I recently removed were like rubber toast. I have to protect these hoses until I can order a set of Russell Braided Hose lines and AN Fitting. But I need my RAV4 to go to work.

I was thinking if I could cover the Derale hoses with this High Temp DEI shield. I'll hold it together with clamps and high temp tape. In your opinion, which would be the best way to cover them? Should I cover them loosely, or use metal clamps making the thermal heat shield contact with the hose? As you can see in the Toyota engine, the hose is covered entirely with the heat shield cover. Or, leave it loose around the hose?

Remember the filter is behind the hot header. The two hoses come out of the oil filter sandwich outlet. Even though the header has DEI wrap. I don't want to be going down the road and all of a sudden oil will spill all over the road because of an oil hose melt down.

 

[mensajero]

good to see that everyone knows what I'm talking about.

 

[pico]

Didn't answer earlier due to schedule.

I wrap my 4:1 headers with fiberglass material. The hotter an object is, the faster it dissipates heat energy.

Taking that as the rule, I shield the hottest area - by the header ports, then downstream with the remaining material. Slightly loose or tight doesn't matter very much.

Looking to the future, depending upon space, a hard shield with an air gap between the hottest component and the part being shielded from heat is a very good beginning, then wrap the component (not the shield.) The key is the infrared heat at the hottest points. Air circulation cannot cool the very hot spots anymore than we can blow the beam of a flashlight sideways because infrared is radiation.

Good luck. If I had your situation I'd be driving on eggs. Take care.

 

[lacro]

good to see that everyone knows what I'm talking about.

I'll take a stab at it. I managed a hose shop for many years so I know a bit about hose and heat. Most rubber hoses (the inner tube) that can tolerate oil are made of Buna-N (NBR) which has a temp rating usually in the low 200's but some formulations may get close to 300 degrees. If your hoses are showing signs of heat deterioration, they will usually become "hard" and may show cracking.

I think shielding is a better choice than wrapping. If you can fabricate a no contact sheet metal shield at the highest heat areas, this will reduce the temp the hose sees quite a bit.

If you have a local hose shop nearby, see if they sell Teflon hose w/ Stainless steel overbraid. It can be fabricated with several different end configurations
including AN (AKA JIC) fittings. This is the industrial version of the Russell ($$$) hose, and is usually made with steel fittings, either crimped or field attachable.

I used to make a lot of race car hoses using Teflon hose. You will have to determine what the ends are on the current hose. If they are threaded, the hose shop should be able to match them as they are probably metric. There are adapters that will convert the metric ports to AN (JIC) so you won't have to use metric ends on the hose.

If the ports are not threaded, and have hose barbs to be used with clamps instead, the choices for high heat hose will be limited.

If you can take hi-Res photos of the ends, I can help identify.

For now though - I think shielding with sheet metal is the best choice.




UPDATE: I took a closer look at your photo. The small blue hose near the bottom right is a 300 degree oil rated hose that would also work, and can be used with field attachable ends. However, I would still shield it from the very close high heat source in a small area.

http://ph.parker.com/us/15551/en/fiber-braid-cover-transportation-hose-206

 

[mensajero]

I think I got my answer. Following what lacro told me. I guess I'm on the right track. The picture below shows how I can wrap the hoses to keep them "cooler" until I can move to setp two, new oil/trans-axle coolers. The one I have, Derale, is OK. But the fittings are not reliable. Russell Performance and Earl's Performance have reliable fittings along with Braided hose lines, like lacro advices. Exposing rubber hoses to heat is asking for trouble down the road. That is the next step. Keep RAVin

 

[lacro]

I think I got my answer. Following what lacro told me. I guess I'm on the right track. The picture below shows how I can wrap the hoses to keep them "cooler" until I can move to setp two, new oil/trans-axle coolers. The one I have, Derale, is OK. But the fittings are not reliable. Russell Performance and Earl's Performance have reliable fittings along with Braided hose lines, like lacro advices. Exposing rubber hoses to heat is asking for trouble down the road. That is the next step. Keep RAVin

Are you going to make your own hose assemblies? You could save some$ if you use "Industrial" steel JIC (AN) fittings instead of the blue/red anodized aluminum aircraft fittings ($$$). Also buying Teflon hose from an industrial supplier should save some $.

Russell offers 2 hoses with a SS overbraid, one with a CPE tube that is good for 350 degrees, and they also offer a Teflon hose which is rated even higher.
The CPE tube hose is more flexible than the Teflon. The industrial Teflon hose is the same thing as the Russell, but uses steel fittings. It won't have the fancy look of the red/blue ends, but will perform just the same for less $

Also, be aware using any SS overbraid hose that they need to be protected from abrasion from rubbing against each other or any metal object. It doesn't take much to wear through the fine SS wire used in the braiding.

The blue hose in your photo (and link I supplied) also has a CPE tube, better abrasion resistance than the SS, and almost the same heat resistance, It's flexible, and it is MUCH easier to assemble with field attachable fittings, that are also less expensive. It's just another option to consider.

Another thing to consider is the actual ID of the hose. Most of this type hose uses a different sizing method (SAE 100R 14). Meaning a nominal 3/8" hose actually has a 11/32" ID. If the factory hose is say 10MM (close to 3/8"), you should probably not reduce the hose size by using a 3/8" nominal (11/32" actual) hose. You should probably go the next size bigger which is 1/2" nominal (7/16" ID) and use an increasing adapter to connect to the ports if needed. This may have already been accounted for by the cooler Mfg. but is worth mentioning.

 

[mensajero]

Thank you, I will follow your advice