[junkyardjeff]

A couple years ago I put a performer intake on a low mile 302 and it started using oil,it has to come apart to repair a noisey valve guide and I picked up a original cast iron intake to put back on. Is there much difference between a performer and a stock intake to make much difference on a stock motor.

[techinspector1]

Originally Posted by junkyardjeff

A couple years ago I put a performer intake on a low mile 302 and it started using oil,it has to come apart to repair a noisey valve guide and I picked up a original cast iron intake to put back on. Is there much difference between a performer and a stock intake to make much difference on a stock motor.

Performer is, in my opinion, a stock OEM design that will make about the same, or a little more power as an OEM iron manifold, but is lighter on the front end of the vehicle. If you are building for power with a carb, use a Edelbrock RPM or Weiand Stealth.

[junkyardjeff]

Its going to stay a stock motor and I just need to stop the oil consumption that started with the installation of the aluminum intake.

[327NUT]

Ok...have to ask, WHY did the alum. intake cause an oil consumption problem???

[junkyardjeff]

Dont know why but the installation of it started the oil consumption,either something went wrong in the installation or the casting. The first aluminum intake I put on was a used one I got off ebay and it was cracked or warped and had a huge vacumn leak so I am not a big fan of them right now so the cast iron one is going on unless when removed I can find the cause easily.

[Hippie]

I bet you find it has been pulling oil through the bottom of the intake gaskets. Bought a 90,000 mile '76 Monte Carlo with a 350 and an Edelbrock intake. The seller said it needed an overhaul, it was smoking badly and using a Qt. every 50 miles and fouling out plugs every 200. I pulled the intake after I got it home and the bottom of the gaskets were oil soaked. I replaced them with FelPro's. No more smoking, oil consumption dropped to 1/2 a Qt. every 2,000 and no more oil fouled plugs.

Can't say on a SBF but on a SBC I don't think an aftermarket intake shows much gain over the stock 4 Bbl. until you hit about 4,500 to 5,000. For a daily driver that rarely sees the high side of 4,000 they are just eye candy. With a few mods like a Performer cam and headers that extend the RPM range then they can help up to 5,500 RPM without a noticable sacrifice at low end on larger engines. But how much do they really help? I used to have tons of test articles but none of them were ever really "apples to apples".

FWIW I'm putting together a 305 SBC for a truck with 9.3 compression, unported 305 L30 Vortec heads, '395 Marine & Ramjet 350 roller cam (mild TQ cam), 1-1/2" full length headers and a cast iron quadraJet intake manifold that was made for Vortec headed industrial applications like generators, pumps, etc. I have a brand new Performer intake for Vortec heads still in the box but I'm using the iron intake for two reasons.

#1 the Vortec heads have no heat crossover passages to warm the intake in cold weather but the iron intake has a water passage to run coolant under the plenum to warm it in cold weather. Aftermarket Vortec intakes, with the exception of the very expensive GMPP intake and the Performer RPM, do not. Why they didn't put the passage in the more street oriented std. Performer is beyond me unless it was to keep cost down. But then turn around and put it in a more race oriented intake?

#2 I believe the Performer would give up too much low end mixture velocity on this small engine resulting in a loss of TQ and fuel economy below 4,000 and that was the primary focus of my cylinder head, camshaft and header selection. This thing should pull hard to 5,000-5,500 but I expect it to really shine from an idle to 4,000, for a 305 that is. If my DD2000 results are close it should fool most people into thinking it's something larger.

At the end of the day it's hard to beat the factory intakes for low end TQ and off idle throttle response.

[cobalt327]

Originally Posted by junkyardjeff

Dont know why but the installation of it started the oil consumption,either something went wrong in the installation or the casting. The first aluminum intake I put on was a used one I got off ebay and it was cracked or warped and had a huge vacumn leak so I am not a big fan of them right now so the cast iron one is going on unless when removed I can find the cause easily.

Like Hippie said- the intake gasket should be suspected as being the culprit.

The Performer has been dyno'ed to death, it always shows a modest gain over OEM, and obviously there's the weight savings of Al over cast iron.
The type of intake gasket makes a difference as to how well the intake will seal. Whether or not the block and/or heads have been shaved can make a difference.

I'd run the Performer intake, no question. Use a gasket like the Fel-Pro Part #MS90361. This isn't a "race" gasket. Nor do you want a steel shim-type gasket.

If you meticulously clean the surfaces and follow the gasket installation instructions and retighten the intake after it heat cycles, it should seal fine.

[454C10]

From the intake dyno test I have seen, the stock 4 bbl intake should make more power and torque until 3000 rpm.

if the cam is stock, car is heavy (3800+ lbs), and the gears are tall, then use the stock intake.

[cobalt327]

Originally Posted by 454C10

From the intake dyno test I have seen, the stock 4 bbl intake should make more power and torque until 3000 rpm.

if the cam is stock, car is heavy (3800+ lbs), and the gears are tall, then use the stock intake.

Looked and I can't find such a test- got a link?
Thanks.

[454C10]

Here is one, not quite a “stock cam” with 224 degrees at 0.050” but look at test 1 and 2. The stock intake and carb is test 1 and test 2 is with a performer intake and holley. At up to 3200 rpm, the stock stuff is making more power.

http://www.popularhotrodding.com/eng...gine_dyno.html



Here is another when the performer intake lost power below 3000 compared to the stock q-jet intake.

http://www.chevyhiperformance.com/te...ild/index.html


Here are a few links, don’t have time to find more. But I have seen this same result for years and years. Plus many recommendations (publications) from engine builders to use the stock 4 bbl intakes if the car is heavy and gears are tall.

[cobalt327]

I can't find a stock engine w/a back to back intake swap either.

[Hippie]

Originally Posted by cobalt327

I can't find a stock engine w/a back to back intake swap either.

There's probably a very simple explanation for that........... they never published any and I think we can all guess why that is.

[junkyardjeff]

The motor is in a big 65 custom 500 4 door and I used Mr Gasket gaskets that came with the installation kit which I will never buy again since the Mr Gasket bolts are junk.

[Hippie]

Originally Posted by junkyardjeff

I used Mr Gasket gaskets that came with the installation kit

That just about guarantees it's your gaskets leaking.

[techinspector1]

It's not the thickness or thinness of the gasket, it's the relationship of the head/intake surfaces. They're not square with each other. The intake gaskets are being pinched like crazy on the outside, but on the crankcase side, they are not being pinched at all, allowing oil vapors to be pulled into the intake ports from the crankcase when the intake valve opens.

Having become tired of this with some motors I assembled in the past, I devised this operation and shared it with others on the wiki.....
http://www.crankshaftcoalition.com/w...lead,_internal