Projects Joe's American Graffiti Coupe with a Man A Fre (Milner Coupe Clone)

Re:the leak/seepage. , did you run a small bead around the coolant ports on the top side of the gasket?

 

We smeared a bit of black silicone around each water port above and below the gasket. I'm thinking that we needed more. Also, we need to tighten down the intake bolts after we ran the engine up to temp. I've purchased some of those GM leak tabs that they use in factory installation of the cooling system. I'm going to warm the engine up and flush in a couple of broken up tabs as well to help it seal.

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I think I'd check that intake out and make sure it's square on the plane.

 

If we have to pull it then we'll absolutely check it out again. It looked good to us.

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Don't know if this was mentioned , you can check with a feeler gauge , at the manifold/head , manifold/ China wall joints to see that nothing this over / under crushing . Gaskets are about .060 so you should be about .010 under that , I like to see the China wall at about .060 .You can cut away excess gasket or silicone to get an accurate assessment...

 

On the manifold leak, I am running an old Fenton tri-power setup on my 327. At the time I built the engine I wanted to run the double hump heads and at that time there were no new castings available, so not knowing how much or how many times the old castings had been milled, I had the intake cut I believe 10 on each side (not the ends) to catch up to the heads. So far, no leaks. D

 

I've got a set of the old double humps too. That's a good idea. I'll look and see what they did with mine.

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I'll definitely check that. I suspect we my have needed to avoid the 1205 Felpro printoseal gaskets. We probably should have went with the old school blue ones that I purchased as well.

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I have read that the old style raised ridge gasket don't always seal well with aftermarket aluminum intakes , something about distortion , used them with an older Weiand aluminum manifold / iron heads successfully..?? Yes you should have used the 1204 or Mr gasket 5820, smaller ports , better match. As an aside, you want enough silicone around the water passages to seal , just not so much that it squeezes into the port. ..

 

Sounds good. We'll look at the 1204 gaskets. I agree. The fitment does not look good. We ran it for about 15 minutes and It leaked a bit. Now it is seeping a bit at each of the water ports. My buddy said we tightened each bolt to 30lbs/ft of torque. We have not retightened them after running the engine.

My opinion is changing. I don't think that we should just retighten the bolts and add leak seal tablets. I have an original restored and sectioned/customized 1932 radiator. I'm concerned that we have more of a fitment problem and I don't want to do damage to the engine, intake, or radiator trying to make this work.

What's y'all's opinion here? What would you do? It is only seeping a drop or two at each port every few days. It has been sitting and not run in about 3 weeks.

(Check pics, you can see damp seepage. Is this normal? Should I just not worry about it?)

Nick

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If it were me, I'd take the manifold to a machine shop and have it squared up. I have an old Offenhauser 2x4 that wouldn't seal. It would wobble around on the head's with no gaskets, got it squared, it layed flat, and quit leaking- vacuum leaks and water leaks. JMO

 

That may be a good idea. I want this time to be a good seal. I'm willing to pay a bit extra to make sure it's right.

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Got to thinking a little more about my intake issues. When I sat the intake on the motor the bolt holes in the intake did not align well (top to bottom) with the intake holes in the heads. This is when I decided to have the intake shaved. Also, when you would screw the bolts into the heads the bottom of the hex on the bolts did not lay flat to the intake indicating an alignment problem also. To cure this, after I had the intake shaved, I used a counterbore bit on the intake holes. I had a pilot made for the bit out of a bolt that I could screw into the head through the intake. Trial and error to get the under head of the intake bolt to lay flat on the intake manifold. Most of the holes I could do with my drill, but some I had to turn the bit with vice grips. Make sure your counterbore is big enough to clear the hex on the bolt head. Hope this make some sense. D

 

It does make sense. We did not see any alignment issues. I'll definitely take a look at our setbupyif we pull the intake again. It looks like we will.

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I think I've figured out why the Aluminum intake is seeping so much. When we were cleaning all the sealant off the intake I thought it was a great idea to use 80 grit sandpaper to smooth out the areas that seal the intake. It had a large amount of grime and stain. I think I will need to have a machinist level all the mating surfaces up before reinstallation.

What do y'all think? Is this an easy thing to fix?

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Grab one of these and check the angle between the end rails and the port sides against a stock manifold.

 

A light shmear of RTV on both sides of the gasket at the water ports should have taken care of any sanding scratches from 80 grit paper. That is not the problem. I'd think the leak is caused by poor alignment. Maybe the aftermarket milling of something caused misalignment. Maybe overtightening during the intake's lifespan has caused warpage. You will probably need to remove the intake, clean all the gasket and goop off the surfaces (carefully and completely), then set the intake on dry to see the gaps or interference on the mating surfaces. Might take some fancy machining to get it right again. Or just maybe a different gasket.

On that note, looking at your pic I see the outline of the old gasket where it dips down between what should be the individual ports of the intake. Since your intake has one giant port, make sure your gasket is trimmed from the unused area, and the raised ribs on the outer portion of the gasket will still seal completely.

 

Looks like the holes for the intake are recessed. Maybe use a copper or aluminum washer with an od that will fit down in the recess. Still not going to help with the fit of the manifold to the head. I would be worried about anti-freeze in my oil or a vacuum leak. D

 

Should I use a thicker gasket? Which one would you recommend? I used Fel pro 1205 first.

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Sorry I don't think of all these things at once. CRS Original intake bolts are I believe 5/8" long. Check that along with maybe some crud in the head manifold holes that are causing the bolt to bottom. If those are blind holes. D

 

The 1205 might be a tad too big port-wise for that manifold. Maybe try a 1204 or a 1256 felpro, they're closer to stock port size. If you want to run a thicker gasket, the Mr. Gasket #101 are twice as thick as the Fel-Pro gaskets listed above, with basically the same port size.

 

Ok. I'll check when we pull the manifold.

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Ok. Would y'all advise using a thicker gasket? Would that help or cause more problems?

I currently have the Fel-pro 1205, 1204 and 1256 for test fitting. I wanted to really check gasket match up. I'm also going to check the square of the intake at a machine shop. Hopefully it's not too bad.

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Is this called a feeler or a square? Don't you use it to check gaps?

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Just an angle finding tool/adjustable square.

Clean the intake and heads mating surface, lay the intake on without gaskets.

Then see if it rocks catty-wampus <technical term>, or sits flush, shine a light at the mating surfaces, see if you have gaps on the ends or in the middle areas, etc.

Someone will post a pic of feeler gauges soon.

 

Check this link:
https://www.ebay.com/i/112655610378..._b2uo0wgdq-22KPJXvt0svBIsRbknt9RoCyV4QAvD_BwE

 

AFTER you get the intake checked and possibly machined square, try to test fit it with the 1256 gasket's to see if the bolt holes in the intake line up with the hole's in the head. If they line up reasonably well, use the 1256 gasket's. If the bolt hole's in the head's are close to the top of, or higher than the top of the hole's in the intake, use the thicker gasket's to try and bring the holes into proper alignment. Be sure to check the intake port's for proper alignment also. The intake port alignment is the most critical part here, and whatever gasket it takes to give the proper fitment is the one you use. There's no set standard at this point, it's trial and error. The bolt hole's in the intake can also be opened up some, if need be, once proper port alignment is achieved. I hope I didn't confuse you with this response. If I did, my appologies, let me know and will try to explain it differently.
When you get the intake back from the machine shop and test fitted with the 1256 gasket's, please send us some pic's so we can see what you are working with.

 

Adjustable sliding bevel T , usually used by carpenters to transfer a bevel/angle. Trim carps friend ...

 

It is adjustable to angle carpenters use it mark angle cuts like rafters. Lay the handle part on the end rails of the manifold and the blade to the port face an tighten bolt. Now check that angle to the other 3 corners and a different manifold. You also flip it over and see if it matches the angle formed by the block rails and the head port surface. Because you do not know the history of the parts. I went to install a new Prefomer RPM and it did not fit right one side was not milled at the same angle as the other Edelbrock replaced it.

 

Ok. We checked that before and it seemed to fit good. I'll definitely check it closely this time.

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