Who has an intake shield ? Is it worth putting in ?

Thanks.

 

I installed one last year while I had the manifold off. To be honest, I haven't noticed any significant changes. I'm sure someone with a little more knowledge on the subject will chime in, however.

 

I think they help...I installed one to avoid oil splash on the bottom of the manifold when I relocated my PCV valve to the intake. I noticed a decrease in the fuel percolation problem I'd had

 

I think you might benifit from it with a all out race car!!
just my 00.02, keep the change

 

Agree,..keeping hot oil off the intake for a cooler A/F mix is always good performance.

 

The shield is, I think necessary, if you have an active exhaust gas crossover running under the carb. The bottom of the manifold will become very hot, and will needlessly heat the oil splashing on it - if you've no shield.

Unless you live in a cold climate, and use the car for a daily driver, I'd think you're better off without the exhaust gas crossover (blocked off by a block out intake manifold gasket); and thereby don't need the shield. You'll get a small improvement in performance with a cooler carb. Also, for more carb cooling, you can get a valley shield to prevent hot oil splashing on the underneath of the intake manifold. Another reason to block of the exhaust gas crossover, is that it probably destroys the effectiveness of headers with the two cylinders effected.

A magazine article I read recommended removing the shield for cleaning, if for no other reason, when you're installing a used manifold. Apparently the area under the shield becomes home to a lot of gunk and burnt oil. Also, if the person who sold you the intake manifold sand/glass blasted it, there's probably a lot of sand/glass caught under the shield....not good if you're installing the manifold on a big buck engine rebuild.

 

Looks to me like the intake will still be as hot as the heads it is bolted to,,,,

 

I put one in my motor, I don't know if it does anything noticeble. I just fiquired it had one on the stock manifold so it couldn't hurt to have for my Edelbrock even though it doesn't have a exhaust crossover.
motor

 

I run the shield in all my engines, with the cross-overs blocked and even after the engine is at running temp, my carbs are merely warm to the touch.

Here's the GM part for BB's:

http://www.gmpartsdirect.com/perform...CATID=611.html

 

This what I would call the intake valley shield. I thought we were talking about the little, maybe 6 inches by 8 inches, shield that was riveted to the intake manifold. To re-iterate my opinion (not a real expert), I think that if you live in a moderate climate country and you car is not a daily driver, you do not need an intake manifold shield - and do block off the exhaust gas crossover. However, a vallley shield is always a good addition. The valley shield will keep the intake manifold from heating up.

 

This what I would call the intake valley shield riveted to the underside of the intake manifold. I thought we were talking about this little, maybe 6 inches by 8 inches, shield that was riveted to the intake manifold. To re-iterate my opinion (not a real expert), I think that if you live in a moderate climate country and you car is not a daily driver, you do not need an intake manifold shield - and do block off the exhaust gas crossover. However, a vallley shield is always a good addition. The valley shield will keep the intake manifold bottom from being sprayed with crankcase hot oil.

 

When I built my 355, I installed one "while I was at it" but don't think that for normal applications there is much difference. Supposedly it keeps hot oil off from the underside of the intake and therefore allows a cooler air/fuel mixture into the engine. Maybe next time an Air Gap intake should be considered but for me I'm not going to worry about it.

 

I have been running blocked heat crossovers & Moroso lifter valley oil baffles for a long time.

Moroso
"Lifter valley baffles increase horsepower by shielding the bottom of the intake manifold from hot oil splash. Also keeps surplus oil out of the valve covers by eliminating oil splash from lifter bores."

Edelbrock
"The air-gap design features an open air space that separates the runners from the hot engine oil resulting in a cooler, denser charge for more power."

 

Interesting stuff.

The vette used to be a daily driver here in Dallas. Not long drives but enough to have fun each day.

I've been thinking about blocking the crossover. Everyone knows we have enough heat around here.

Should a daily driver have a blocked off crossover? It seems not but don't understand why.

 

That's true, but the oil doesn't need to be heated from the exhaust gasses, GM used a shield on some of their factory intakes.

 

I blocked off my crossovers (Performer RPM) and made my own lifter valley splash shield out of a piece of galvanized vent pipe. Does it work? My mild combination makes about 300 hp at the wheels so couldn't hoit!

As Lars will tell you, it's the sum of the parts and anything and everything counts.

My combo:

331 CI, pump-friendly 9.5:1 CR
K&N 14"x4" air filter, Corvette drop base and lid
Holley 600 dp, choke horn milled, polished
1/2" Aluminum open spacer port matched to manifold, exterior polished
Edelbrock Performer RPM, port matched, exterior polished with all extraneous castings and lettering removed
Homemade lifter valley splash shield to keep hot oil off manifold bottom
Camel hump 1.94/1.50 heads hogged out to 2.02/1.60, pocket ported, port matched, pump-friendly hardened seats, 3-angle valve job
Comp Cams 1.52:1 roller-tip rockers
Crane Cam Vintage Muscle 327/350 hp cam, 222 degrees @ 0.05, 0.447" lift (with 1.50 rockers)
Doug Thorley headers, dechromed and ceramic-coated
2.5" mandral-bent exhaust (including tips), 2" cross-over just before rear axle
DynoMax stainless Ultra Flow mufflers
Mallory Hyfire IV CD ignition box triggered off Accel points
Mallory high voltage chrome coil
Mallory spiral-wound coil wire
Mallory solid copper plug wires, ends soldered to wires
Champion plugs
37 degrees total ignition advance (now 34 degrees per Lars tune-up)
Carter high volume fuel pump
Melling high volume oil pump
Open breathers
Polished aluminum high flow water pump
Flex fan with polished aluminum spacer
Polished aluminum one-wire 100 amp alternator
Muncie M-20 CR 4-speed (now Keisler TKO600 5-Speed)
Hurst shifter (Now Keisler With Hurst Tower)
3.70:1 positraction
225/60/15 Firestone Firehawk SZ50s on 7”-wide Western 30-spoke Turbine Wheels

At the time of the dyno pull, engine had never been professionally tuned up. Car did 293 ft-lb and 293 hp @ 5,500 rpm on the chassis dyno. Engine pulls to 6,200 rpm and does over 200 ft-lb from 1,900 rpm. This was prior to some clean-up work around the junction of the carburetor and base of the air cleaner that smooths the flow through this area and a Lars tune-up and should be good for a few ponies. Car has run 107 mph in the high 13's (old, bad tires) at the quarter. Car is extremely streetable and could probably even run 87 octane if it had to. (I can't get the engine to ping no matter how far I advance the ignition.)

The secret to power is in the attention to details!

 

This is just my 2 cents here, not trying to say anybodys ideas are wrong, if you think it will help, it will. BUT if it was a help to use a shield, why do none of the intake manufactures built them in to there intakes?

 

GOOD POINT!!!

 

They did,..almost all intakes from the late 60's and 70's had a tin 'baffle' revited to the underside of the intake to protect the oil from cooking from the heat of the cross-over. If you've ever seen the underside of an intake that had a functioning cross-over without the baffle, you'll see a "petro udside-down cake".

The 'valley shield' is more of performance item to keep hot oil from heating the intake and carb, and is used with GMPP intakes and heads (mostly re-branded Edelbrock stuff) or most any other performance heads/intakes.

Most performance intakes and heads don't have the cross-over provision,..for a reason.

 

Seems there are two aftermarket valley shields - one steel, one alum.
Anything wrong with using the alum. one ?