I had intended to have a nice easy swap. Clean it up, slap on some performance parts, and call it a day. The clean up definitely took longer than expected. The engine block and heads were greasier than an Arby’s dumpster, though the rat population was probably lower, a thing I was grateful for. I scrubbed wire brushed and decreased for what felt like several days, and then brought it back into the garage.
While significantly cleaner, it was still filthy. I looked it over and realized that this engine had a thin candy shell layer of rust scale over the whole thing. I’ve dealt with rust before, but scale like this is another of the wonderful things about aquatic environments like Michigan. Because of this, I became acquainted with a tool I never knew before. This magical tool is called a needle scaler.
After some work with the needle scaler, the block was not fully clean, but clean enough to proceed. Because I'm adding a much more aggressive cam, and hope to make power for another thousand RPM beyond the stock redline, it was necessary to change the valve springs. Though I know I should be using a "3/4 race cam" so that my Falcon could "hop a coke can" and "tape a hundred dollar bill to the dash and give it to anyone who could grab it while I accelerate", I was tipped off to the cam (actually my whole engine plan) I'm using by this article from Hot Rod. It's a Lunati Voodoo 272/280 cam, which should have good driveability and pull strong until 6000 RPM. While it's popular in the hot-rodding world to have a big cam for a "lumpy" idle, I prefer to have a car that doesn't drive like crap 90% of the time because it surges and bucks at low speed and will barely idle at 1500 RPM.
I ordered a set of valve springs from Alex's Parts because they have a setup specifically for explorer engines that are getting a more aggressive cam. I had planned to change the valve springs with the cylinder heads attached, so I took out all the spark plugs
Some of the spark plugs were non-compliant, so I subjected them to an overwhelming display of force, brought to you by DeWalt. They quickly complied.
With the spark plugs out, I could insert my home-made cylinder inflator which provides a supply of compressed air through the spark plug hole. This would, in theory, apply force on the intake and exhaust valves up so that I could compress the valve springs and remove the retainer. At that point I would replace the spring, retainer, and keepers with the new, higher performance version from Alex's Parts. And this is what happened on the first cylinder.
On the second cylinder, the process did not go as planned. When I hooked up the cylinder inflator to the air compressor I heard the rushing of great winds. And when I compressed the spring, the valve went down with the spring. I soon noticed that the great winds were not a force of nature, but the ghost of a 302 escaping out it's exhaust valves. Now in a fantastic mood, I removed the cylinder heads and shined a ridiculously powerful flashlight in the exhaust port. The light was easily visible through the burned valves.
As I checked the other valves, I found another valve that was not sealing. I didn't bother checking the other head because I knew at that point that both heads needed a valve job.
This left me highly irritated. I had once already considered return this engine on account of it's poor exterior condition. By this point I was outside warranty, so returning wasn't even an option. I had also paid an extra $200 for this engine because it had GT40 heads. Had I purchased a GT40P headed engine, I could have saved $200 on the engine, $300 on the head rebuild, and $150 on the springs and been at least halfway to a really nice set of aluminum heads, or 90% of the way to cheap aluminum heads. I rolled the dice on this engine and lost. I always thought Yahtzee was a stupid game. Sending this engine to the Arby's dumpster where it belongs started to sound more appealing.
As irritating as all this is, dwelling on it doesn't get me anywhere I found a local guy to rebuild the heads. It seems like a decent job, the only complaint I had was that I had to pay an extra $50 for one o' them fancy 3 angle valve jobs. It felt a bit like getting charged extra for "unleaded" gasoline. Does anybody even still do single angle valve jobs?? There are cutters that do all 3 angles in one pass!
I had initially planned to have this guy "set up" or measure and shim my valve springs to put them at the right installed height. After looking into it, I found I could buy the tools and parts to do it myself for about the same price as paying him to do it. And when that's the case, the answer is always to buy the tool!
It took a while, but I measured all the spring heights and it turns out only two of them needed shims. The valve heights were all surprisingly consistent, so I hope that is an indicator of careful machine work.
Hopefully I'll soon find the time to finish cleaning up the block, so I can paint it and start on the motor mounts.
Since the last post, I also made some progress on making the garage a good workspace instead of a hoarder's hideout. Some quick work with the chopsaw and a bit of 2x lumber yielded a workbench.
A little more work, and I had a 14 foot workbench. It's not fancy or even flat, but it's adequate for the work I do.
The garage buddy approves.
He's not the only one who is excited to drive this car.
In the past weeks I've had a few nights to work in the garage after the garage buddy goes to bed (he's not actually a very good garage buddy, I have to constantly keep him from killing himself. I think that's mostly what parenting is...) I'll keep taking these hour and a half baby steps a few times a week and eventually, maybe before the summer is gone, I'll drive this old heap.
I ordered a set of valve springs from Alex's Parts because they have a setup specifically for explorer engines that are getting a more aggressive cam. I had planned to change the valve springs with the cylinder heads attached, so I took out all the spark plugs
Some of the spark plugs were non-compliant, so I subjected them to an overwhelming display of force, brought to you by DeWalt. They quickly complied.
With the spark plugs out, I could insert my home-made cylinder inflator which provides a supply of compressed air through the spark plug hole. This would, in theory, apply force on the intake and exhaust valves up so that I could compress the valve springs and remove the retainer. At that point I would replace the spring, retainer, and keepers with the new, higher performance version from Alex's Parts. And this is what happened on the first cylinder.
On the second cylinder, the process did not go as planned. When I hooked up the cylinder inflator to the air compressor I heard the rushing of great winds. And when I compressed the spring, the valve went down with the spring. I soon noticed that the great winds were not a force of nature, but the ghost of a 302 escaping out it's exhaust valves. Now in a fantastic mood, I removed the cylinder heads and shined a ridiculously powerful flashlight in the exhaust port. The light was easily visible through the burned valves.
As I checked the other valves, I found another valve that was not sealing. I didn't bother checking the other head because I knew at that point that both heads needed a valve job.
This left me highly irritated. I had once already considered return this engine on account of it's poor exterior condition. By this point I was outside warranty, so returning wasn't even an option. I had also paid an extra $200 for this engine because it had GT40 heads. Had I purchased a GT40P headed engine, I could have saved $200 on the engine, $300 on the head rebuild, and $150 on the springs and been at least halfway to a really nice set of aluminum heads, or 90% of the way to cheap aluminum heads. I rolled the dice on this engine and lost. I always thought Yahtzee was a stupid game. Sending this engine to the Arby's dumpster where it belongs started to sound more appealing.
As irritating as all this is, dwelling on it doesn't get me anywhere I found a local guy to rebuild the heads. It seems like a decent job, the only complaint I had was that I had to pay an extra $50 for one o' them fancy 3 angle valve jobs. It felt a bit like getting charged extra for "unleaded" gasoline. Does anybody even still do single angle valve jobs?? There are cutters that do all 3 angles in one pass!
I had initially planned to have this guy "set up" or measure and shim my valve springs to put them at the right installed height. After looking into it, I found I could buy the tools and parts to do it myself for about the same price as paying him to do it. And when that's the case, the answer is always to buy the tool!
It took a while, but I measured all the spring heights and it turns out only two of them needed shims. The valve heights were all surprisingly consistent, so I hope that is an indicator of careful machine work.
Hopefully I'll soon find the time to finish cleaning up the block, so I can paint it and start on the motor mounts.
Since the last post, I also made some progress on making the garage a good workspace instead of a hoarder's hideout. Some quick work with the chopsaw and a bit of 2x lumber yielded a workbench.
A little more work, and I had a 14 foot workbench. It's not fancy or even flat, but it's adequate for the work I do.
The garage buddy approves.
He's not the only one who is excited to drive this car.
In the past weeks I've had a few nights to work in the garage after the garage buddy goes to bed (he's not actually a very good garage buddy, I have to constantly keep him from killing himself. I think that's mostly what parenting is...) I'll keep taking these hour and a half baby steps a few times a week and eventually, maybe before the summer is gone, I'll drive this old heap.
Jesse ~ The exhaust seats on Ford heads are induction hardened, which is generally fairly shallow in depth. Soooo.....by the time they need a valve grind, the exhaust seats on high-mileage Ford heads are usually heavily-pitted to the extent that they must be ground PAST the heat treating.
ReplyDeleteThat's why most competent machine shops recommend the installation of hardened exhaust seats as part of a valve job/grind. Typically, high-mileage heads that are ground and assembled w/o hardened seats will immediately begin "sinking" the exhaust valve as the "soft" seats erode.
As the valve sinks, the v/spring tension gradually diminishes resulting in decreased rev limit AND the lifter plunger moves downward until finally bottoming ~ which manifests itself by changing yer V-8 into a V-7, due to the valve being held unseated.
Ray (aka "TurboRay")
Hey Ray,
DeleteA couple thoughts on this...
No doubt you are correct about the induction hardened seats. However, I'm not too concerned. First, if the shop had suggested hardened seats, I would have told them to get lost. I figure at a minimum, it would have been another $200. At that point I'm just buying aluminum heads. Second, being a big(ish) NA engine instead of the litte overboosted tractor engine, the exhaust heat is spread out over double the cylinders we're used to. Surely that counts for something. And finally, this car is honestly not going to get that much use, so 10,000 miles is probably a decade's worth of use. Half the year it has to stay in the garage due to crappy Michigan weather, and the other half, it's just a weekend car.
In any case, I'm not too concerned. It'll last long enough to serve it's purpose. Eventually I'll either get respectable aluminum heads or a totally different engine platform.
Yeah.....you can probably get by w/o hardened exh seats on a rarely/barely-driven car, Jesse. OTOH, I'm reminded of the v/grind I did on my wife's soccer-mom '88 Aeroslug 3.0 about 20 years ago, wherein it wound up running on 5 cyls less than a year later (8-9K accumulated?).
DeleteAfter realizing that the "condition" was due to a "low hole", I pulled the heads and discovered that all the exh valves had sunk about 1/8-3/16" (most exh-valve heads were at or below the chamber surface).
The valve in the misfiring cyl was the big winner.....as it had beat all the others in the race to "bottom" the lifter plunger and hold the (subsequently-burnt) valve unseated, lol!
Ray
That's pretty crazy. From what I've read, a lot of the survivability of the seat has to do with the alloy of the head casting. I wonder if the 3.0 has especially bad iron for that sort of thing?
Delete