A Few More Intake Manifold Questions

[Mongoose930]

Dis-assembly went relatively smoothly today and now I am in the process of cleaning up the manifold, block and heads so that I can reinstall my manifold. I test fit the new gaskets and made in interesting discovery. My Blue Thunder Manifold does not have cooling passages in the back - only in the front. The Blue Thunder website isn't that great so I looked for pictures of the Edelbrock and Offy intakes and they are the same way. Why would the heads have coolant passages in the back, the gaskets have holes for these passages but the intake does not have the passages? Is this right or do I have the wrong heads or manifold combination?

My second question is regarding the oil baffle that is supposed to be in the valley under the manifold. This is referenced in the Steve Christ "How To Rebuild Big Block Ford Engines". I do not have this baffle. Is this going to be a problem and should I put one in?

[farmerdave]

FE heads don't have a "back" or a "front". They're the same, either head can be used on either side. To do it any other way is stupid.
As for the manifold, why have coolant passages at the back when the thermostat is at the front?

[Mongoose930]

Hi Farmerdave - That actually makes a lot of sense but you would think that ford would have some type of plug for the unuesed rear coolant passages. The reason that I have to change my intake manifold is that I was getting anti-freeze into my number 7 & 8 cylinders and based on my compression testing, it does not appear to be a head gasket problem. I am sure the coolant is under some pressure when it comes up the rear coolant passages and hits the intake "wall". This pressuse must eventually cause the gasket to fail. I might have this all wrong but hat is what I am envisioning.

[ERA Chas]

So which gasket set are you using?

[rustyBob]

its that way so you can use the gasket on either side also.......put it together and dont worry about it.....it will work.

[Mongoose930]

Hi Chas - I just finished installing the gasket and I went with Cometic P/N C5137-060 since I already had a set. I also had a new Felpro 90145 that I bought since it came with the cork rail gaskets while the Cometic didn't. After dry fitting everything, it was clear that the cork gaskets were too thick and I went with a bead of the Right Stuff as everyone as suggested. I also saw your recommendation Felpro 1247S3 which looks nice a set up. The Felpro website is terrible and I couldn't find the difference between the 90145 (which has a metal core) and the 1247S3.

In the end it may not matter as when I was torqueing down the bolt between cylinder 2 & 3, the threads stripped. I can't begin to tell you how frustrated I am right now.

I think I can get a slightly longer bolt as the manifold has a step in it for that bolt. I may try that and then this winter take it all apart and put a helicoil in. Or, while it is still pretty much all apart, pull the manifold again and put the helicoil in right now. For now I will have a cocktail and sleep on it...

[ERA Chas]

I'm sorry for your understandable frustration-but...
Although I have no experience with the Cometics, the 1247 S-3 is the problem-solver.
I think the difference with the 90145 is the face material. The S-3's (also with steel core) have near 'lineoleum-like' faces which do not absorb coolant like fibrous materials. Absorbing coolant causes inferior gaskets to wrinkle, twist and shift allowing them to pull away from the water ports, letting coolant into the intake ports.
Designed by Barry Rabotnick and put into FelPro's catalog, they're the real deal. Also, ditch cork gaskets forever -use R/S or the Motorcraft sealants.
I wouldn't waste your time with a popcorn gasket recommendation.

[lovehamr]

MG930, you don't have to worry about that oil baffle either. In factory applications it's put there to alleviate the oil coking problem on the bottom of the intake where the exhaust cross-over is. Since you aren't sending hot gasses through your intake it's a non-matter for you.

[ERA Chas]

You may want to install a PCV there however...makes leaks go away.

[Mongoose930]

I do have the PCV basket and valve.

I am going to try a slightly longer bolt and try to torque the manifold. It all else fails, I will order the S3 gasket set and start over.

[ERA Chas]

Best luck.

[Gaz64]

Originally Posted by Mongoose930

Dis-assembly went relatively smoothly today and now I am in the process of cleaning up the manifold, block and heads so that I can reinstall my manifold. I test fit the new gaskets and made in interesting discovery. My Blue Thunder Manifold does not have cooling passages in the back - only in the front. The Blue Thunder website isn't that great so I looked for pictures of the Edelbrock and Offy intakes and they are the same way. Why would the heads have coolant passages in the back, the gaskets have holes for these passages but the intake does not have the passages? Is this right or do I have the wrong heads or manifold combination?

My second question is regarding the oil baffle that is supposed to be in the valley under the manifold. This is referenced in the Steve Christ "How To Rebuild Big Block Ford Engines". I do not have this baffle. Is this going to be a problem and should I put one in?

A lot of engines including V8s are like that.
Water comes back to the engine from the radiator on the water pump inlet, through the block from front to rear then through the heads from rear to front,
out through the thermostat to the radiator, or via the bypass hose if thermostat is closed.

As others have said, assemble it correctly and don't worry about water "hitting a wall".

[RICK LAKE]

Mongoose 930. For the stripped hole, clean out the threads and use a stud until the season is over. Tighten stud in hole to bottom. If you have a little PB welding puddy, add this to the hole. Not sure which heads you have, aluminum or iron. They have kits for both. Works well when harden. Options for permanant fix in winter, drill and tap to metric size bolt, timesert the hole which is a little over kill but last forevery and can do repeated top motor repairs with no problems of retorqueing. Last Helicoil, cheaper and quicker to do with a low failure rate. The last repair way doesn't like multi torque and retorqueing done. Just my 2 cents and 30+ years of using different things to repair stripped holes. My Shelby heads came with helicoils and over time they loosen. I raced with this and broke a rocker shaft. The helicoils came out on the ARP stud. 11 years have gone by since using timeserts in the heads and no problem with loosing torque specs. This is for an aluminum head. good luck with your repair.
For manifolds, Most don't have the hole for the heater pipe tapped any more with a valve to supply flow to the heater core and back to the water pump. My Dove doesn't. Have seen some guys tap both back areas and run lines back to the front of the motor to help the heads run a little cooler and make more power in the motor. This is for race motors.

[undy]

With regards to your stripped intake bolt, that was one of my problems during assembly... I had to come up with a solution.

All the bolt kits out there seem to be designed around cast iron heads, where they don't need to go as deep into the heads because they're grabbing iron. I solved my problem by "inventing" a set of stainless steel intake studs. No one else had made a set. I bought some hardened stainless steel all-thread from a local fastener supplier. I went to work measuring, cutting, chamfering and hack-sawing a slot in one end for a screwdriver install. You can run them down, all the way to the hole's bottom. That utilizes ALL the threads, not just 50% or so of them. Since then I've NEVER had another stripped hole or leaking gasket. They torque down very solid now. In addition, they make it real easy to bolt down other items like throttle linkages, halon fire extinguishing lines etc.

I also ended up helicoiling the stripped 3 hole, utilizing their 1" long helicoils.

[FWB]

ditto on the stripped intake threads.....2nd time i had the intake off i lost a couple too.

i got pissed and ripped both heads off and installed

these on all the holes


can now torque down with no worries

got em' thru Mcmaster-Carr

Fred

[Mongoose930]

I just bought the 3/8-16 Timesert kit. I was going to use Helicoils but the Timeserts seem to be a more elegant solution. Kit should be here by Tuesday.

Also bought more Right Stuff - the smaller tubes that go with a caulk gun - great deal on Amazon right now. I figure I will have better control with the caulk gun than with the aerosol can.

I will be ordering the Felpro 1247 S3 gaskets tomorrow from Survival Motorsports since my 12 hour old Cometic gaskets were destroyed when I pulled the manifold back off this morning. No wonder why my back is killing me!!

All in all, this has been very challenging but I have learned a lot about my car and I feel confident that when I put this next gasket in, it will be functional for a long time.

[Mongoose930]

Almost Forgot - Thanks to everyone for their help and advice. I will keep you posted on my progress.