Author Topic: Intake Manifold Gasket Recommendations  (Read 1881 times)

s2ms

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Intake Manifold Gasket Recommendations
« on: August 18, 2021, 02:50:59 PM »
Hi All,

Looking for some intake manifold gasket recommendations for my specific situation. I've read the other threads here on this subject, and other forums, and combined with all the other stuff I've looked into online my head is spinning.

Removed the  Cobra intake on my 66 because I strongly suspected oil was leaking past the gaskets which has been confirmed. Heads have been ported, port sizes are 2.20" x 1.24", intake ports have also been opened up to 1.97" x 1.12". From the look of the gaskets that were removed I bet they never sealed well and have been slowly leaking from the get go. Removed gasket thickness was .060". I'll check into this a little more after everything is clean, but the manifold does seem to line up as expected with the heads and I don't see any warped surfaces.

Since the .060" thick gasket wasn't cutting it I was thinking of going to a thicker gasket, thoughts?

There seem to be lots of choices out there on port sizes, should I size the gasket ports based on the larger head port size or the smaller manifold port size?

Any opinions on the "printoseal" gaskets? I've read everything from awesome to crap.

I do plan to use RTV on the ends. I was also planning to block the exhaust crossover ports but can go either way on that.

Any recommendations on specific brands and part numbers that have worked, or not worked, in similar setups would be greatly appreciated. Or am I completely overthinking this and should just go with a standard Fel-Pro and call it good? I do hear good things about Victor Reinz gaskets but they seen very hard to find.

Thank you!

Dave
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Cobrask8

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Re: Intake Manifold Gasket Recommendations
« Reply #1 on: August 18, 2021, 03:24:55 PM »
I run the AFR 185 aluminum heads, with the big ports, and use the FelPro 1262 Intake gasket set. There is also the FelPro 1250, but I am not sure if that is stock port size or larger.

Look up the part numbers and confirm the openings sizes.

gt350hr

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Re: Intake Manifold Gasket Recommendations
« Reply #2 on: August 18, 2021, 05:05:56 PM »
   Use the 1250 or 1262 "S" which has the inner steel layer , without printoseal.
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SFM5S000

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Re: Intake Manifold Gasket Recommendations
« Reply #3 on: August 18, 2021, 08:01:03 PM »
Hello Dave,

I run the FelPro 1250s on a set of ported HP289 heads done by Louie Unser hence the HU stamping (Heads by Unser) according to Randy. The Intake port openings measure 2 1/16 (my ruler is slightly bent as it was too long to rest flat) x 1 1/8.
Im a little confused on your measurements: 2.20 x 1.24? and 1.97 x 1.12 which is it? Im guessing the latter.
Attached are a few pics I just took. The measurements, the FelPro 1250 on the head (held in place by studs on the ends and green frog tape in the middle.
You can see how close they are.
There is even a shot down the Weber intake (I run Webers, Randy is not a fan of them) the intake is ported as well.
Anyway there you go. You didnt mention what heads youre running, HP289 or aftermarket?
Hope this helps. Lemme (us) know on those measurements???

Cheers
~Earl J
« Last Edit: August 30, 2021, 11:33:32 AM by SFM5S000 »

s2ms

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Re: Intake Manifold Gasket Recommendations
« Reply #4 on: August 18, 2021, 10:45:45 PM »
Thanks Dan, Randy, and Earl for the help!

Earl, sorry for the confusion with the port sizes. The 2.20 x 1.24 measurement is the intake port size for the heads, 1.97 x 1.12 is the port size in the Cobra intake manifold , slightly larger than stock. Thanks also for the photos. Do you cut the FelPro 1250 water jacket opening square to match the port on the heads or just leave it as is?

Unless I find something indicating I need a thicker gasket, the FelPro 1250's look like a good choice, port sizes are 2.00" x 1.20", in between my head port and manifold port sizes. These are also ported HiPo heads, so there is not a lot of surface area on the head port bottom for a gasket to seal, I assume having as much gasket material as possible is a good idea. The FelPro 1262 is a little wider than the 1250. I'll likely go with the 1250-S3 version, I like the idea of the inner steel layer.

Thanks again!

« Last Edit: August 19, 2021, 01:49:03 AM by s2ms »
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corbins

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Re: Intake Manifold Gasket Recommendations
« Reply #5 on: August 19, 2021, 08:28:42 AM »
Would never run print o seals on anything ever again.....

shelbydoug

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Re: Intake Manifold Gasket Recommendations
« Reply #6 on: August 19, 2021, 09:49:01 AM »
The Mr.Gasket  213 is old school and thicker then the Fel-pro. Works fine. This engine likes old school for some reason.

Just don't use the cork valley gaskets. Use silicone there.



IF you are really stubborn and insist that the cork is "correct" and you therefore are compelled to use it, consider this. COBRA S2MS intakes are notorious for being fragile on those "outrigger" bolts at the back and on more then one occasion, that tab on the manifold has snapped off.

Do you really want to torque those bolts down enough to compress these cork things?



My T/A, C60A intake was throwing me some kind of a fit and kept leaking in the left rear corner.

New AFR 1388 heads and new C60a intake. It seemed to be some kind of a temper tantrum? It had nothing to do but waste my time and make me redo it three times?

The Fel-Pro's were at the center of this controversy. Technically the cork gaskets did compress on the bench in a vise to what they should have on the engine but just didn't inexplicably on the engine. Now I have banned them from use on this engine and recommend that you do also.
« Last Edit: August 20, 2021, 08:48:06 AM by shelbydoug »
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trotrof1

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Re: Intake Manifold Gasket Recommendations
« Reply #7 on: August 19, 2021, 09:53:29 AM »
 I Second that  on the Mr Gasket brand. I also use a thin layer of Indian Head on the water ports.

SFM5S000

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Re: Intake Manifold Gasket Recommendations
« Reply #8 on: August 19, 2021, 02:56:54 PM »
Thanks Dan, Randy, and Earl for the help!

Earl, sorry for the confusion with the port sizes. The 2.20 x 1.24 measurement is the intake port size for the heads, 1.97 x 1.12 is the port size in the Cobra intake manifold , slightly larger than stock. Thanks also for the photos. Do you cut the FelPro 1250 water jacket opening square to match the port on the heads or just leave it as is?

Hello Dave, Yes, I do trim off the little piece at the front water port. It sits practically in the middle of the coolant flow.
As for the choice of FelPro vs anything else, To each their own.
I know my head surfaces have been milled, (my chambers are at 47ccs, see pic) so therefore the manifold NEEDS to be machined accordingly. If not, its not going to matter whose gasket set you use. Its going to leak.
Too many people overlook this detail or dont bother to check, then suffer the consequences.
Mine dont leak.

Cheers
~Earl J
« Last Edit: August 19, 2021, 02:58:45 PM by SFM5S000 »

67350#1242

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Re: Intake Manifold Gasket Recommendations
« Reply #9 on: August 19, 2021, 04:33:01 PM »
Use the steel core gaskets unless you want to do it over when they split.
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s2ms

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Re: Intake Manifold Gasket Recommendations
« Reply #10 on: August 19, 2021, 09:05:43 PM »
Thanks all for the additional comments.

I live in a cork-free zone so will be using RTV on the ends. I've narrowed down my choices to the steel core Fel-pro 1262-S3, which matches my head intake port size a little better than the 1250, or the thicker Mr.Gasket 213 which also matches my port size very well.

As soon as I get everything back together I'll let everyone know how it goes...
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s2ms

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Re: Intake Manifold Gasket Recommendations
« Reply #11 on: August 29, 2021, 08:36:43 PM »
Have everything cleaned up, should get it back together this week.

Curious to hear opinions and experiences with blocking the exhaust crossover ports? I keep reading they aren't really necessary with an aluminum intake and may actually be beneficial to block them. Car is never driven below about 45F if that makes a difference...

Thanks,
Dave
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gt350hr

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Re: Intake Manifold Gasket Recommendations
« Reply #12 on: August 30, 2021, 10:13:54 AM »
   Dave
        Blocking them will keep the intake a bit cooler as the exhaust heat isn't going through it. Oddly , it makes the exhaust note slightly louder.
   Randy
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s2ms

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Re: Intake Manifold Gasket Recommendations
« Reply #13 on: August 30, 2021, 02:02:37 PM »
Thanks Randy! Louder is good, although with Delta-40 Flowmasters and 2.5" exhaust I'm probably close to the limit already...
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Re: Intake Manifold Gasket Recommendations
« Reply #14 on: August 31, 2021, 10:24:45 AM »
Louder is good, although with Delta-40 Flowmasters and 2.5" exhaust I'm probably close to the limit already...

Dave,

That's what I have on my '67.  It is loud enough that I have to sneak into the neighborhood at night to avoid waking up small children and getting their parents POed at me!

Roy Simkins
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