Terry,I run a PCV on my crossram.It sounds like you should run a sheild,my crossram must have been designed not to use a sheild.
intake manifold
- Thread starter dunhamfield
- Start date
Milodon makes one
Milodon makes a lifter valley baffle if you really think you need one. An aluminum intake will not get any hotter than the water running through it. On the other hand Smokey recommends Cold outside air through an insulated carb. and a hot engine and intake runner to keep the gas suspended. That's why all the wood and plastic spacers today. Intake will stabilize at water temp. Olds had the right idea years ago. All of the mfgs. are using cold air intake on a hot engine today. Want to go fast use a cool can for the fuel line, outside ram air to the carb and insulator between the carb and manifold.
Milodon makes a lifter valley baffle if you really think you need one. An aluminum intake will not get any hotter than the water running through it. On the other hand Smokey recommends Cold outside air through an insulated carb. and a hot engine and intake runner to keep the gas suspended. That's why all the wood and plastic spacers today. Intake will stabilize at water temp. Olds had the right idea years ago. All of the mfgs. are using cold air intake on a hot engine today. Want to go fast use a cool can for the fuel line, outside ram air to the carb and insulator between the carb and manifold.
Ray, Nobody is suggesting that anyone take off a shield. If its on there, leave it there. If it aint broke--dont fix it. But why blame Offy? Ive never seen a shield on any brand of aftermarket intake. It aint about profit, its just not needed, at least in my opinion.
fatride said:If Ya'll want that hot oil splashing on the bottom of your intake reducing your intake charge, by all means, remove the shield. I'll be waiting for you at the finish line: only my thoughts, I may be full of ****.
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geezzz man,,, You should watch all this I`m the bada** racer dude that wins all the time stuff !!
Aren`t you just finishings that first real racey engine and car ???
Confusious say :Fancy pants and fresh car can cause very full belly of crow !!!
dq409 said:geezzz man,,, You should watch all this I`m the bada** racer dude that wins all the time stuff !!
Aren`t you just finishings that first real racey engine and car ???
Confusious say :Fancy pants and fresh car can cause very full belly of crow !!!
:takethat Ouch,:takethat Ouch,:takethat ouch. I'll have to watch my bench race ravings from now on.
no1: I was a little grumpy last night :evil .
No heat riser
Aftermarket performance manifolds don't have the crossover for the exhaust so no shield. Thats the only reason its there and why its called a shield not a baffle. Still, does not harm being there or using one. Maybe on an engine with a lot of blow-by it serves a purpose by accident.
Aftermarket performance manifolds don't have the crossover for the exhaust so no shield. Thats the only reason its there and why its called a shield not a baffle. Still, does not harm being there or using one. Maybe on an engine with a lot of blow-by it serves a purpose by accident.
Firepower354
Well Known Member
How 'bout pouring the head passage full of aluminum then there's an "air-gap" where the crossover in the manifold was...
Thermal barrier coating on the bottom? We coat the bottoms of about everything. Really does help. DIY kitand a cheap electric oven in the garage or at your buddy's house
All the "racey" guys use a vac pump anyway, right? Then you can seal it right up. No road drip tube, no mushroom headed breather..
Thermal barrier coating on the bottom? We coat the bottoms of about everything. Really does help. DIY kitand a cheap electric oven in the garage or at your buddy's house
All the "racey" guys use a vac pump anyway, right? Then you can seal it right up. No road drip tube, no mushroom headed breather..
12555320 Manifold Oil Shield
An oil splash shield improves engine performance by isolating the intake manifold from the hot engine oil in the lifter valley. This lowers the temperature of the fuel/air charge and increases its density.[/QUOTE]
Not my words, but I still belive this to be true. Only my opinion though.
An oil splash shield improves engine performance by isolating the intake manifold from the hot engine oil in the lifter valley. This lowers the temperature of the fuel/air charge and increases its density.[/QUOTE]
Not my words, but I still belive this to be true. Only my opinion though.
How current is that quote?
When was that written and by whom? Anybody run an oil temp gauge? I would think oil in the lifter galley is around 180-200 at its hottest. Manifold would be that temp or hotter with water passages and connection to the heads. How much hotter can it get. If you don't completely block the exhaust crossover in the head, you have 1200 degree air touching the intake. I don't think it has anything to do with a modern built engine.
When was that written and by whom? Anybody run an oil temp gauge? I would think oil in the lifter galley is around 180-200 at its hottest. Manifold would be that temp or hotter with water passages and connection to the heads. How much hotter can it get. If you don't completely block the exhaust crossover in the head, you have 1200 degree air touching the intake. I don't think it has anything to do with a modern built engine.
more detail to come
Early simple answer from friends at Wilson Manifold. Engines that use the exhaust crossover (GM) attach a sheet metal shield riveted to the bottom of the intake to prevent the oil splash from 'coking' or burning to the bottom of the intake in this hot area. More details to follow as time permits.
Early simple answer from friends at Wilson Manifold. Engines that use the exhaust crossover (GM) attach a sheet metal shield riveted to the bottom of the intake to prevent the oil splash from 'coking' or burning to the bottom of the intake in this hot area. More details to follow as time permits.
GM Performance parts thinks this is needed!http://www.crateenginedepot.com/store/Oil-Shield-12555320-P1185C60.aspx
Only one of many sites/ threads that I have read supporting the splash shield lowering intake manifold temps for better performance. This is my last post on this "HOT" topic.
Only one of many sites/ threads that I have read supporting the splash shield lowering intake manifold temps for better performance. This is my last post on this "HOT" topic.
M
MK IISS
Guest
Some of the "Z11" style valley pans, maybe it was the '62 version, had a heat shield. Not sure why because the heat passageway was in the upper intake.
Sorry Richard, I am unclear on this. I have never seen a Z11 intake in person. Are you saying that a Z11 intake had a exhaust crossover provision in the intake manifold? Why would a race only engine have an exhaust crossover? If so, maybe there is more to this heat deal than we know. The engineers who designed the intake must have wanted the heat going through the intake, even for race only. I dont know, as I said, Ive never seen one.
Someone did research showing that a "limited" amount of heat in the intake made for better fuel atomization. Can't remember where I read this. Article addressed the heat passage block off issue.
M
MK IISS
Guest
Ronnie: Maybe someone can post a picture of a Z11 intake. It has a heat passage way just like the regular 409/409-425 intake. Of course the heads do also. In my opinion Chevrolet originally planned to use the "Z11" style heads/intake, which first appeared in 1962 as over the counter parts, on the regular production 1963 2X4bbl 409 but changed their mind and only used them on the '63 RPO Z11. I have this opinion because of the heat passage. I've seen the '62 and '63 version but not at the same time. Fred has seen a side by side comparison of the 62 & 63 versions....they are different castings. There was also an "experimental" Z11 intake that had open plenums and a single 4 bbl. NASCAR version.
not a GM part
According to that web site/dealer, chrome wire looms make the engine faster. That number is a sku not a part number. Even so if GM thought it was important they should have installed it in the crate engine. I'm done, I see there are many sides and possible answers to this one.
According to that web site/dealer, chrome wire looms make the engine faster. That number is a sku not a part number. Even so if GM thought it was important they should have installed it in the crate engine. I'm done, I see there are many sides and possible answers to this one.
dunhamfield
Well Known Member
OK guys, I have decided to replace the missing shield. I have located one at a place called Chevy 409 performance Parts in Ca.
As far as plugging the crossover, I,m thinking that I will leave it stock as well.
I am not building a race engine, I am building an engine with lots of low end torque to put in my 56 Chevy pick-up. It will be driven daily.
Thanks again for all your inputs as I'm sure that I will have many more questions during this build.
As far as plugging the crossover, I,m thinking that I will leave it stock as well.
I am not building a race engine, I am building an engine with lots of low end torque to put in my 56 Chevy pick-up. It will be driven daily.
Thanks again for all your inputs as I'm sure that I will have many more questions during this build.
damnitdave
New Member
Pics of the 348 / 409 shield?
Wondering if anyone had a pic of the stock 348 / 409 shield? I think I'm going to have to make one. Do any GM parts interchange with this shield?
Wondering if anyone had a pic of the stock 348 / 409 shield? I think I'm going to have to make one. Do any GM parts interchange with this shield?