As I have mentioned in my "problems with my 1973 400" thread, I have noted a problem that I have never seen in a gasoline engine. However this was concidered normal in diesels in years gone by. I'm talking about compression lock.

As you remember, I'm working with a 1973 Ford 6.6L 400/V8 engine. My complaint was excessive pinging. I later learned that I had not properly setup the new Edelbrock 1406 4-Bbl carb to my cars specs. Changing the fuel metering rods eliminated most of the pinging. However I still have some. It was recommended that I retart ignition timing from 14 BTDC to 6 BTDC. Upon trying that setting and restarting the engine I ran into what I termed compression lock.

Using an analogy, I likened the experience to two gears meshing together and then throwing a wrench between the two gears stopping them suddenly then pulling the wrench back out, allowing the two gears to mesh together in rotation. That is what happened when I retarded my ignition timing.

What I need to know is what caused compression lock on an engine that has a compression ratio of 8:6.1 to 9:0.1??? For a diesel engine with a 17:5.1 to 19:0.1 or higher, this is normal. But not on a gasoline engine.

Are there any engine mechanics or engineers on forum who might know what happened, what caused it, and how to remedy this problem. At 14 BTDC ignition timing, there is a slight and almost unnoticable lock, but the engine spins more free and starts like normal. But at 6 BTDC, the compression lock physically stops the engine momentarily then resumes normal rotation.

***Note, this is NOT a fuel lock. Nor is this a flooding problem. Nor is there a starter problem. And I don't believe there is a problem with the flex-plate, because there is NO dynamic or static vibrations.

Is there anything else in a gasoline piston engine that can simulate these conditions? And though I have never in my life heard of it, is there any chance that the timing gear could've jumped. On the 385 series Ford engines, this was my experience but not on the 335 series Ford engines.

Like I've mentioned before, my engine is 31 years old, but only 103,000 original miles. The former owner bought this car brand new, and was a gentle driver. This engine is clean, no leaks, and its overall operation suggest that this engine was very well built. Also I know by looking at its history records, this engine has never been torn into except when I had Edelbrock intake installed. This engine performs well through the power curve all the way to WOT.

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Have you ever seen a grocery gitter fly???

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"Ususally" if the engine stops turning for a second or "kicks back" during starting it is caused by too much timing. You might have a build up of carbon in the cylinders.

 

If you are using a lower octane fuel and have and engine that runs a bit on the warmer side you may experience this. If the centrifugal advance system in the distributor is stuck in the advanced state it could cause a hard start problem like you described as well. If the spark plug wires are experiencing an inductance problem it will cause this as well. Basically check all of the ignition for a problem that causes a spark plug to fire at the wrong time.

 

My race truck will do that when it gets hot. I solved it by putting a switch on the positive coil wire. With the coil off, start cranking the engine, once it is rolling hit the coil switch and your engine will be running.

 

I have long suspected an excessive carbon buildup. I have thought of many fixes to the problem and I remember someone once telling me to put Marvel Miracle Oil into the fuel tank, which would go through the fuel system and through the combustion chambers and exhaust ports. I know that excessive carbon buildup can cause higher compression, as well as higher combustion chamber temperatures which lead to premature ignition.

Now as far as gasoline fuel, well thats a very much heated debate and believe it or not, most people don't know that there is a difference in gasoline depending on where a person buys their fuel. I am a former gasoline tanker driver, and I have hauled gasoline and diesel fuel from many different refinerys. That experience is why I buy from the retailer that I do. Many refineries use blended fuels that we drivers actually blend while loading the truck. Some do not use additives. The gasoline I use is non-blended and carries a 90 octane rating.
The average blended gasoline has an 85/15% ratio. This varies with brand and some use a 3-way ratio. Gasoline that is sold in certain state during the summer or "hot weather season" is called "E-85". That fuel uses a cocktail that is very volitile usually using grain alcohol in very high proportions. Normal unleaded gasoline sold through out the country is the 85/15% mix with detergent additives and other admixtures. And heres the problem with that. For people like me that don't like using blended fuels in our autos/trucks, we develope a varnish buildup from the fuel tank all the way through the combustion system. Then if we happen to fuel at a retailer using the blended fuel, the alcohol used in the mix immediately cleans that varnish, breaking it loose and causing it to flow through the fuel lines and deposits that "gunk" into the float bowls. It can cause the engine to run rough, stall out, and run hot. You may ask then, why do I run straight fuel if I know of its side effects, well I from a professional standpoint believe the non-blended fuel to be a better fuel, especially for an older engine like mine. Less likely to freeze up in cold temperatures, and less likely to vapor lock. I also believe that varnish buildup I spoke of actually helps the valves to seal better, and keep engine tighter. Thats just my observation. So maybe from time to time, it might be good to add some MMO to the fuel mix and help control this buildup.

I'm not going to interferre with refineries and their business practices but if anyone in the midwest region wants to know what station sells which fuel, you can email me personally and I'll do the best I can to answer your questions privately. But you will be surprised to learn that even with gasoline, you get what you pay for. I just gave away a huge clue with that one, now you figure it out for yourself when shopping for fuel retailers. Do you know how clean that retailers underground tanks are, probably not but I might. I could write a book on this issue alone.

Hummmm, an override switch. Where have I seen that idea before?????????????????

 

Check the wires to the starting motor. If they are hot you might need heavy gauge wires. I use #2 AWG.

 

Did you alter the hood hinges to make it flip up like that? Nice looking F100.

 

If it is a problem with kickback, do what we did. Run a Double 0 negative battery cable. The starter will have no problem turning over even a hot motor.

 

I need one of your pills, LOL.

 

That is a aftermarket kit to make the hood flip foreward.

Thanks for the comment.

 

I think there's something wrong with the way you're setting your timing, higher timing in degrees increases chances of pinging and harder starting, retarding the timing will alleviate this.

Are you using a dial-back timing light? Are you sure you're operating it properly?

Which direction are you turning the distributor to retard the timing?

It sounds like you're advancing it when you think you're retarding it, or something strange.

Another possible avenue of investigation might be the markings on your balancer.

 

I just started with a new trucking company and I'm gonna have one of them take my car home with them and work on it. First thing I'll have them do is remove and correctly reinstall distributor. It seems that the last mechanic did not reinstall the distributor correctly and may be the cause of my current problems. I placed the new distributor myself when I bought it and while they were working on my intake, they may have removed it and didn't take the time to correctly install it.

While they have it out, I'm gonna have them check one more thing I was made aware of just last night. I didn't know that Ford used Nylon teeth on the cam shaft lobe for the timing gear. It was brought to my attention that those teeth may have wore down due to age and may need attention. If thats the case, I'm gonna go ahead and order the Edelbrock camshaft kit that is part of the performance package that goes with my engine. While we're at it, might as well go ahead and replace timing gears and chain with same that is also found in the Edelbrock package for my engine.

And where I think I have a problem with my main bearings as was told to me might just be the oil pump itself. I've had many Ford engines that went bad due to worn mains, and this engine I have now gives no indications whatsoever that there are any problems in the bottom end. So I'm gonna have the mechanic go ahead and pull oil pan, check mains and replace oil pump.

While I was checking online for remanned engines, I found a 400/V8 long-block near San Diego, CA for $1350.00 and I'm gonna check it out some more. When I made contact with Jasper engines here in Indiana, they want $2300 for the 400/V8 they build. But theirs comes with a 3yr/75K warranty. I have some more investigation work to do before making any moves but I'm thinking that since so much needs to be done to my engine, lets just go ahead and pull it and start fresh.

If anyone knows of any good reman engine companies with a good price and warranty let me know. The engine I have is 31 years old with 103,000 original miles and I would be better off replacing the engine than continue messing with the one I have.

 

Anything over 80K miles is suspect with the original OEM nylon timing gear, I always replaced them with good straight up aftermarket parts as part of routine maintenance.

Mosty of the reman engines are rebuilt with mismatched parts. Factory rods are a matched set. It is better to get an original non-rebuilt core and have it rebuilt by a good machine shop. Check with your local chapter forum for good shops in your area. You can also have the engine deck and heads milled to get a small compression increase. If you get lucky you might find a set of 400 flat top pistons on ebay. There are threads here, some very recent, with piston discussions on the 400.

btw- on these low compression engines the "compression lock" is just pre-ignition due to advanced/incorrect ignition timing or hot spots in the engine.

Keep reading here and you will learn a lot!

 

Yes Eric, I agree that I am learning quite alot. Johnny 5 needs input.....

I am currently in talks with two different engine rebuilders and it's getter harder to decide which direction to turn. Price alone will cause me to go one way, but reputation, warranty and quality of work could make me go the other way which will cost more.

I'm looking at going with a high-performance Ford 400 with 300Hp and impressionable torque. Both companies have said it's very possible and they can do the work. Jasper engine company said that they use a flatter piston than stock, and with the Edelbrock intake and carburetor I have will easily produce 300+Hp and they will still give me a 3yr/75,000 mile warranty but they cost twice what the competition charge. The other shop in southern California claims they can make the same engine but cost much less however they don't have much of a warranty.

I'm tempted to use Jasper because I have delivered loads to their facilities before, they are local, and the method they use to reman an engine is an experience to say the least. They don't reuse anything from the original engine except block, connecting rods, crank and camshaft. Everything else is brand spanking new. They also correct for original manufacturers mistakes and changes within the engine building industry. I've done my homework as you can tell. I thought the extra up front cost was just associated with the name but upon a quick tour of plant and operations, I've seen the light.

Here's where Jasper engine company sold me, they look at the vehicle, it's application, how it will be used, and build the engine accordingly. They even took the time to tell me up front that my transmission will not work with a high-performance engine and that for $1275 dollars, they will match engine and transmission together to ensure long life. The new transmission is setup for higher torque, and high horsepower. And when installation takes place, the parts kit comes with all new gaskets, belts, hoses, clamps, thermostats, and everything else to complete installation. Nothing gets reused. In the end, I'll have a brand new car that needs paint touch-up and thats it.

Heres the part that hurts me at the moment. Total cost for this project is $5800.00, but like I told my brother, you can't by a brand new car for that price anywhere but I just don't have that kind of money just laying around. So until I can save that much, I'm pretty much stuck with what I have. When it gets warmer, I'm parking the car and start riding the 1974 Honda CB750 I just rebuilt.

You are probably scratching your head wondering why I insist on a high performance engine and transmission, and here is my reason. $900 dollars. It only cost $900 dollars more for the option, and with that much power/torque, I'll be able to climb out of Laughlin, Nevada going east much easier. Laughlin is at 500' ASL, and going east out of Laughlin there is a very steep/long grade that levels out around 3000' ASL. When I took my former new pickup truck with Vortec engine up that grade with trailer, I managed 5 Mph in second gear with the accelerator floored the whole time and half way up it overheated. I think my old car with 300+Hp and matched transmission pulling the same tandem axle trailer can do better. I planning a trip in the future from Indianapolis to Las Vegas via Laughlin, NV. It's a beautiful town along the Colorado river.

When Jasper builds my new engine, I will insist that they not use parts in new engine that contain nylon, plastic or other composite materials.

I guess in closing, the problems that I'm currenly experiencing (low oil pressure/ignition timing) can all be traced back to that nylon gear on the camshaft that everyone keeps telling me about. If confirmed, it wouldn't cost all that much to just get another camshaft installed without that nylon gear, and replace timing gear and chain while I'm at it. That could hold me over until I can save back enough money to have engine rebuilt and new transmission installed.

 

It is those connecting rods that bother me the most. The factory rods are a matched set, the rebuilders slap anything together. Re grinding a cam can be done but it is not an optimum solution either.