Gaskets? Check. RTV? Check. Expertise? Yeah, right. Replacing the intake manifold on a small block Ford isn't really that hard to do. It's basically only six steps: remove the distributor, remove the carb, remove the manifold, reinstall the manifold, reinstall the carb, reinstall the distributor. Of course, each step actually involves many other little steps, but who's counting. As long as you perform each step "correctly," then there won't be any leaks later on.
Step one: Remove the distributor. Easy. Remove the cap, unplug the vacuum line, and take out one bolt. But not so fast. The distributor can go back in with the rotor pointing in like 20 different directions and only one will work. The best way to ensure that it goes back in oriented the same way it came out is to turn the crankshaft to TDC so the rotor is pointing at the number one plug wire. That way you know where it's supposed to be pointing when your done. Google told me this points the rotor towards the driver at about 1 o'clock.
As you can see mine's more like quarter to 12. Not a big deal except that the vacuum advance canister isn't pointing to the front like it should be. The gear on the distributor causes it to rotate when you lift it out.
The rotor rotated to about 10:30 so if I line it up to where it originally was then it should rotate to the customary position.
Step two: Remove the carb. Pretty straightforward. Remove the linkage, remove the PCV hose, disconnect the fuel line, and undo the four nuts. Before I lifted off the carb I checked that the linkage was adjusted to the right length. I opened up the carb linkage all the way and tried to reconnect the linkage. It wouldn't fit even with the loud pedal all the way to the floor. So, something to adjust when it all goes back together.
When I opened up the throttle it sprayed a bunch of fuel through the carb. Removing the carb revealed a lot of fuel had seeped past the gasket. Hopefully this is just a leaky gasket and not a leaky carb. You can also see that I have an open spacer on top of the Edelbrock dual-plane manifold. It should really be a 4-hole spacer that keeps the two sides of the plenum separate.
Step three: Remove the intake. Starting at the rear, I disconnected the water temp wire, the power booster vacuum hose, the heater hose, and lastly the thermostat housing. After removing the 12 bolts the manifold lifted off with very little prying.
Flipping the manifold over I saw that the front cork gasket was out of position. This cutout is right behind the distributor and someone had applied a lot of sealant from the outside in an attempt to seal this area. Needless to say, I will not be using the replacement cork end gaskets.
When I looked down in the lifter valley of the engine I was a little surprised. The block casting says "HECHO EN MEXICO." Obviously this is not the original block. When Ford stopped making the 289 in 1968 they started up production of a replacement block down in Mexico. This new block was designed as a 302 with a heavier casting and beefier main bearing caps like the Hi-Po 289. So it's possible I actually have a 302 instead of a 289--depends on what crankshaft I have. The only way to know for sure is to pull a head and measure the stroke.
There is what I assume to be a partial VIN on the rear of the block which looks to be 2K526084. I think the K means it was assembled in Kansas City but that's all I can figure out for now.
Two things in the above shot. First, it pays not to skimp on antifreeze. This car had been sitting for a long time and desperately needs a flush. Second, the old gasket cutouts looked a little big for the intake ports. Sure enough, when I checked the old gasket it measured 2.067". Then I moved the calipers over to the new gasket.
The new gasket is the correct 2.00" so you can see the difference. In an ideal world I'd have the heads and intake ported to match the gasket, but that would involve removing the heads.
Step four: Reinstall the intake manifold. Whoa, not so fast. All mounting surfaces must be prepped first. This is the most time consuming aspect of the whole deal. If the surfaces of the heads and intake aren't clean then the gaskets won't seal. I was a little disappointed that I couldn't pinpoint the exact area the manifold was leaking, but it was probably leaking in multiple places since the surfaces were wet in many places. So I definitely need to take the time and get the surfaces as clean as possible.
While I have the manifold off I wanted to address the paint.
Someone painted the manifold a nice silver (I hope it wasn't Edelbrock), but obviously didn't prep it right so the paint bubbled badly. I'll see what I can do to smooth things out before painting it a nice Ford blue.
Well it's not perfect, but it's definitely better. I followed the directions for the paint and sprayed on three coats, waiting 10 minutes between each one. The can says for the paint to fully cure you need to place the manifold in an oven for an hour at 200 degrees. Since my wife will probably read this I didn't do that. I swear. I'll let the engine heat cure it when I fire it back up.
I went to dry fit the gaskets and check the clearance under the manifold when I ran into a snag. The gaskets I ordered from Amazon were Fel-Pro 1250S-3. They are listed on Amazon and the Fel-Pro website as fitting a stock head 289. Lies I say.
The opening for the water jacket is so big it overlaps the edge of the head.
How does a big company screw this up? Luckily, the local Autozone had a different Fel-Pro gasket MS90103-1 in stock that was supposed to fit my engine. This new gasket fit way better but it had the heat riser cutout which the other gasket didn't have. Living in Florida I definitely don't need hot exhaust gases heating up the manifold.
Amazingly the black 1250S-3 gaskets came with block-off plates even though there wasn't a hole to block. That was very fortunate since the blue MS90103-1 didn't come with any. I had to use my Dremel to cut the block-off to fit.
Here a shot to show the differences in the water jackets of the two gaskets. While I was prepping the heads I found more characters "1M9L" stamped in the block by the distributor.
One of these days I'll have to pull the starter so I can read the casting numbers and finally figure out where the block came from. With the headers on the way it'll be a bear of a job reaching the starter.
Here's the spruced up manifold in place with a new 4-hole spacer on top. I finished putting everything back together and the engine fired right up--yeah, dream on. So far in this project, whenever I've taken something apart and put it back together the same way I've run into hidden problems.
The first snag was reinstalling the distributor. I knew this was going to be a beyatch from past experience. The problem is re-aligning the oil pump driveshaft with the end of the distributor. Since my distributor wasn't oriented correctly when I removed it I needed to rotate it clockwise 20-30 degrees so the hex end of the shaft was never going to been lined up. If that wasn't bad enough, the bottom of the shaft is attached to the oil pump, but the top end is free to wobble around side to side. When I looked down the hole for the distributor the driveshaft was always leaning to one side.
An easy trick to getting things to line up is to drop the distributor in place until it hits the top of the driveshaft and then turn the crankshaft, which rotates the distributor, until the shaft lines up and the distributor drops down. Tried that. Didn't work. I rotated the engine a full 360 while pushing down on the distributor and it still wouldn't drop into position. And now my rotor was a full 180 out of whack. I didn't want to continue rotating back to TDC just yet because I wanted to static time the engine later on.
So on to trick #2. I removed the distributor (remembering to keep it 180 degrees from normal) and used a small socket on a long extension to reach down the distributor hole and rotated the driveshaft in small increments until things eventually lined up. And I didn't drop the socket inside the engine.
With the distributor in place I needed to static time the engine. The vacuum advance was now pointing at the radiator like it should, instead of the driver's headlight. First, I rotate the crankshaft another 360 to bring cylinder #1 back to TDC. But I stopped with the balancer pointer at 9 degrees before TDC. Then I rotated the distributor until the points opened (that's when the coil would fire). With my multimeter checking continuity across the points this was fairly easy to do. But I noticed something peculiar that should have raised a red flag. Normally my meter will read "1" for an open circuit and "0" when you touch the terminals together. When I checked the points, however, the meter still read "0.4" when the points were closed. I was still able to static time the distributor but I failed to see any problem with the points. Apparently, when I had checked to gap on the points with my oily feeler gauge I contaminated the contacts.
So of course, when I tried to fire the engine, no go. I suspected the ignition right off so I checked for a spark. I pulled the coil wire from the distributor and placed the end near a ground and cranked the starter. No spark. Now I'm suspecting the MSD box. Maybe I fried something, maybe a fuse blew, maybe a wire came loose... I wasted several hours tracing wires, checking voltages, and still couldn't find a problem. I looked up how to test the MSD. Simple. Disconnect the only lead running to the distributor and touch it to ground. Spark! So the MSD is working but the spark isn't getting through the distributor. It finally dawned on me that the points were probably the culprit so I went online to see if the local Autozone had a replacement in stock. They did, although when I picked them up the counter guy thought they were for a tractor.
With the new points installed the engine fired right up--but it still wouldn't idle below 1100 rpm. I'm pretty certain I did a decent job of sealing the intake manifold so it's time to move on to the carb.