Intake Manifold Idea, I want your oppinion please

[cjsupra90]

Hey guys, I am getting ready to start building the intake manifold for my motor. Not sure whether I want to just build a new larger volume plenum with front mounts TB(s), or do a complete new manifold, runners and all.... Now the idea that I have been pondering about if going the route of complete manifold (runners and all) is Stainless insted of the usual aluminum. My thoughts behind this is stainless's great heat rejections abilities. I dont see any bad side effects to this but at the same time, Im not sure if there is enough benifet to doing this or if there truely any benifet at all.

What do you guys think? I cant recall ever seeing anything like it so I am beginning to think that it might not be a good idea at all and there my be a factor that I am over looking. What are your thoughts and or oppinions?

 

[cjsupra90]

Oh, one more thing and not that this probably will make a differance, but this is for a twin turbo setup.

 

[Turbo4L]

DON'T make it our of stainless!
one of the reasons is heat soak, plus you have to then drill injector holes and so on.
If there is enough people who are serious i could arange some sort of group buy. just use a single 90mm tb if you can as its a lot easier.

Cheers

Ben

 

[cjsupra90]

DON'T make it our of stainless!
one of the reasons is heat soak, plus you have to then drill injector holes and so on.
If there is enough people who are serious i could arange some sort of group buy. just use a single 90mm tb if you can as its a lot easier.

Cheers

Ben

Not saying that you are wrong, but could you explain how stainless would cause heat soak especially when aluminum has a higher thermal conductivity rate then stainless by far. With Stainless the heat soak should be eliminated or just about.... My understanding is that this is why a lot of manufactors have gotton away from aluminum fuel rails and gone back to steel or insulated thermal plastics.... Now I do understand that once the heat has gotton in, stainless would keep it in, but being that there is constant airflow, I dont see how it could first off get in and second, stay in..... This same principle but in reverse applies to exhaust headers. Stainless headers lower underhood temps over mild steel because it retains more of the exhaust heat inside the tubes which yes, aids in exhaust scavaging (benificial in two ways there. This has been tested and proven countless times and is all because stainless has less thermal conductivity then mild steel and thus the main reason for ceramic coating of mild steel headers......

Again, not saying or trying to prove you wrong, just would like evidance to back or prove your claim.....

Thanks

 

[Zuffen]

Stainless is a mongrel to work and drill.

Stainless is far more inclined to suffer embrittlement and crack welds than alloy.

Alloy may have its drawbacks but it has a lot of advantages over Stainless.

 

[cjsupra90]

Rod, I follow you on the flaws of stainless in general. I work with it on a daily basis in all aspects of fabrication. I build the turbines and exhaust for Westinghouse nuclear generators which are entirely made from SUS347 along with some of the stuff being Inconel.
__________________________________________________

I did just have another idea allowing the use of aluminum and having great heat rejection...... have it ceramic coated!!!!!!!!!!!

What are the thoughts about that????

 

[Jake Breyck]

hey chris i see where you are comming from on the stainless and rejecting heat. in a well deigned intercooling systems the intake air is colder then the air around the intake manifold so the trans fer of heat would be from out to in.

I think the stainless would be really cool polished up,
the ceramic coated aluminum would have a very bussness look to it.

I was thinking on my corolla i would make the intake out of aluminum but cover it with this gold wrap like on the firewall in this pic.

 

[z8]

Chris -

I recently built a plenum and runners out of stainless for my Mustang project. There is no way I would EVER consider doing it again, as it is a giant PITA. Stainless has a tendency to move around a lot when being welded, so everything must be fixtured up or you have no chance of ever getting it straight. Aluminum is just much easier to work with and is the way I would go. See pictures of the stainless manifold at www.kaneva.com/mytoys (look under Mustang project).

Ernie

 

[Jake Breyck]

to everyone tell him how hard it is to work with....


Chris welds stainless steel togather all day long at work. hes plenty capapable of accually makeing the part, his question is if it would serve a porpose at all in keeping out heat from the intake air.

it is not at all constructive to tell him its hard to do, he knows exacly how hard it is becouse he makes the equilivant of 10 of these things a day every day.

 

[cribbj]

I did just have another idea allowing the use of aluminum and having great heat rejection...... have it ceramic coated!!!!!!!!!!!

What are the thoughts about that????

I had nearly every piece of my intake + the fuel rail for my 2JZ-GTE coated at PolyDyn with their heat shield or heat reflecting coating. I thought it was money well spent. No use trying your best to bring cold air into the motor when the manifolds and fuel rail are sitting there soaking up heat. The coating process does a great job of protecting the aluminum from corrosion, also.

They might be tough to fit, but phenolic insulators for the manifold wouldn't be a bad idea either.

 

[Zuffen]

Assuming you can fab Stainless (which you obviously do for a living) then I see no reason why you wouldn't do it.

Assuming your nuclear exhausts don't crack I figure you have cracking in your inlet beaten.

I've heard of ceramic coating lifting off alloy inlet manifolds as the fuel can get under it and set it loose. Haven't seen it first hand only heard about so take it for what that is worth?

 

[JustenGT8]

DON'T make it our of stainless!
one of the reasons is heat soak, plus you have to then drill injector holes and so on.
If there is enough people who are serious i could arange some sort of group buy. just use a single 90mm tb if you can as its a lot easier.

Cheers

Ben

A group buy of what Ben? a manifold that ditches the lower half would interest me for sure

 

[XR8tt]

Some good ideas...I like thoughts outside the square...
Every so often a good idea comes up...


I have issues with my fuel boiling in my turbo Ford on extended dyno
tune's on hot days.. Yes I have alloy fuel rails...
Everything hot and cold pipeing is ceramic coated...
I never thought of coating the rails...
I guess if s/steel works on exhaust side?
Then why not induction side???
Two Honda S200 adapted manifolds seem to work and look real nice...

 

[cjsupra90]

Assuming your nuclear exhausts don't crack I figure you have cracking in your inlet beaten.

Nope, no cracking. They are X-rayed before being put into use and all welds are magnaflux once a month once in use.

The main reason for welds craking in stainless is carbide precipitation at the welds. This makes the weld very brittle. This is mainly a problem when using 304 or other low unstabilized grades of stainless. I would only build it out of 321 and or 347 which are both stabilized grades and the likelyhood of cracking is almost non existant.

I've heard of ceramic coating lifting off alloy inlet manifolds as the fuel can get under it and set it loose. Haven't seen it first hand only heard about so take it for what that is worth?

I have heared the same thing and if I did go this route, I'd only coat the outside. Less effective, but still better the bare aluminum from a heat transfer standpoint.

 

[White ls400]

I dont know about you guys but at work we repair more cracked alluminium parts than stainless, and stainless is a lot easier to weld as long as everything is locked in before welding and youd be less likely to damage threads after extended periods of use and motor tear downs . When using alluminium make sure the fasteners are 309 grade no higher or less but by the sounds of what you have said im sure you know your ****

 

[Turbo4L]

I've been thinking of doing a semi billet plenum for us 1uz fans.
We would billet the plenum base and the injector mounts, along with the fuel rails and the plenum flanges.We would then just fab the top section and use one of our 90mm tbs on it.
Have no idea on cost just yet , i would most likely have to make a batch of 10 for us to stop making our other plenums.

Sorry, yes it would be from the head.

 

[RedPhoenix]

GB Chris? Thanks. haha