Second Generation Chrysler

[Frank Acampora]

A Bridgeport mill would have made my life easier but the drill press will do.
Here we have my latest project, started on a whim. It is a three cylinder, 85 horse Chrysler from the late '70s. The first two photos show the interior of one cylinder and the porting I have done. This is not my usual mode. Typically I leave all four ports and thin the webs. This time I decided to eliminate two inter-port webs. Having larger bypass ports does no good if the bypass channel does not have adequate area and volume and can not service them so I added two lower ports that will open to two matching ports in the piston skirt.

The third and fourth photos show the same port treatment on the exhaust side. Only one port has been done so far. I am also contemplating adding a 1/2 inch spacer plate under the stainless one to add exhaust chamber volume and reduce backpressure. That's a lot of work though and could be added after the engine is running so---
The engine will be bored .030 over, (you can see a nice groove in one cylinder wall) will have Prestolite ignition and I am also contemplating increasing the compression.

Next summer I will post results on whether or not this engine turns out to be a fire breather.

 

[fucawi]

Re: Second Generation Chrysler

Nice

 

[wolfie-uk]

Re: Second Generation Chrysler

should be a very interesting project mate, will follow this with interest

 

[Frank Acampora]

Re: Second Generation Chrysler



---And here we have the ported pistons before freeing the rings and decarbing with oven cleaner.

Originally I was going to use a block that needed boring but it seemed a bit silly to spend 500 bucks in parts for a test engine. I had another complete block with good cylinders so I decided to use that one instead.

 

[fucawi]

Re: Second Generation Chrysler

Brilliant Frank ..sadly I have to stick to water pumps !!

 

[Faztbullet]

Re: Second Generation Chrysler

Frank dont take this post wrong as this is my $.02, observation,technical and race experience:
The extra holes you drilled in block to match pistons just killed the crankcase pressure. When the piston is at TDC, the power ports on piston are at the cylinder intake ports allowing crankcase vacuum and atmospheric pressure to fill crankcase. When piston is on down stroke to pressurize the intake charge these new holes will open way before piston reaches BTD and max crankcase pressure. It would been better to scallop cut the lower side of intake and piston like the Johnson GT as it adds some CFM to intake charge. Remember that the intake charge also displaces the remaining exhaust gases in cylinder and if pressure is low the cylinder will not be able to "purge" itself of spent charge.

 

[Frank Acampora]

Re: Second Generation Chrysler



Fazt: All I am doing is, in essence, trying to copy the best Chrysler ever made. Unfortunately, it was only made for a couple of years and only made in the two cylinder version. Of course, I don't have the tooling to make the square ports that the engine in these photos has and indeed, it would be too much work by hand. Additionally, the block I am using is regressive compared to the block shown in these photos. However, I believe that since the piston ports and extra ports I drilled in the cylinder wall are on the crankcase side, they will not affect pumping. This is very possibly the oldest crossflow design you can possibly find with very little block packing so there is a lot of room for improvement. I had considered scalloping the bottom of the piston skirt instead of drilling the ports, but rejected that option for a couple of reasons.

However, it is, as I said, a whim and an experiment to see what can be gained. When I square the ports on these blocks, I usually gain around 5 HP per cylinder. If I do not gain at least that, I will consider it a failure. It will not cost me much besides my time so if it is a failure---no harm, no foul.

 

[emeraldG]

Re: Second Generation Chrysler

Truly a nice project. I really like Chrysler.The ride quality and style is great. It's good to know that The Chrysler Group has declared plans for a major investment in its Jeep manufacturing plant in Toledo, Ohio. Chrysler's $500 million investment will go toward improvements for the Toledo North Complex. The cash will be used for facilities expansion and for employing extra workforce. Chrysler to invest $500 million in Toledo Assembly Complex

 

[jerryjerry05]

Re: Second Generation Chrysler

emeraldG The're talking outboard motors not cars.

 

[stubtail]

Re: Second Generation Chrysler

As I have a few 105's in various states of disassembly (realize you are modifying an 85), I am always interested to see what others are doing to push the envelope a little. Your pics are dated in '03. This has been on the back burner for a while? Looking forward to hearing how this one works out.

 

[Frank Acampora]

Re: Second Generation Chrysler

Photos are dated 03 because I never reset the camera. It is an older Kodak. Everytime I take out the card, it disconnects the batteries and it becomes a PIA to reset it again and again. My VCR is still blinking 12:00 too. That should give you a clue to my age. LOL

Do not modify the exhaust ports on the 4 cylinder engines. You will actually lose power over stock. Reason: Exhaust ports are open about 120 degrees while crankpins are 90 degrees apart. All cylinders dump into a common exhaust chamber and #2 and #3 cylinders fire right after each other. With the 30 degree overlap, enlarging the ports without reducing backpressure or isolating cylinder exhausts will result in MORE exhaust blowback into the cylinders, thus reducing power.

One of my future projects will be to modify the stainless plate to help isolate top two cylinders from the bottom two to try to overcome this engineering deficiency.

The 105 is truly a nice engine, although they only deliver about 90. Around 1982 when rating went from crankshaft to propshaft, Chrysler simply rebadged them as 90 with no modifications. You can, however, swap TC carbs and manifolds from a 120, 125, 135, or 140. These larger carbs will not greatly improve the power --you might get 1-2 MPH more--but will improve the response, especially low end.

 

[stubtail]

Re: Second Generation Chrysler

Framk, thanks for the information. As for the dates on your pictures, at least you own a digital camera! Still like what you have up your sleeve and keenly await the results.

 

[Texasmark]

Re: Second Generation Chrysler

View attachment 123296View attachment 123297View attachment 123298

Fazt: All I am doing is, in essence, trying to copy the best Chrysler ever made.

And the winner is................. let me guess, the 60 hp twin?

Mark

 

[Texasmark]

Re: Second Generation Chrysler

And the winner is................. let me guess, the 60 hp twin?

Mark

Bump

 

[Frank Acampora]

Re: Second Generation Chrysler



Well, I was going to wait until I had something of more substance, but since you seem anxious, here on the right is the high compression head I will be using. Hmmmm---Maybe a nitrous bottle too.--Nah.

And yes, Texas, I make no secret that I think the two cylinder 55,60, and 65 series engines were the best Chrysler ever made. They were almost the pinnacle of crossflow design

 

[86 century]

Re: Second Generation Chrysler

will there be any cooling problems with the higher comp and looks like less cooling flow.

 

[Frank Acampora]

Re: Second Generation Chrysler

No--no cooling problems. They are two different designed heads. The one on the left is older style with the thermostat on top of a cast-in tube running down the head. Thus, for added cooling it has recesses in the sides. This is the reason why all head gaskets still have slots in them. The head on the right is the newer design and has a plate over it with the thermostat cover mounted to it. When the thermostat opens, water runs down the whole surface of the head.

These just happened to be the two handiest heads for the photo and the old style was used just for combustion chamber volume comparison.

 

[tater76]

Re: Second Generation Chrysler

So how much was shaved off the head? and did the machine shop have any issues doing it?

 

[Frank Acampora]

Re: Second Generation Chrysler

Chrysler said that .010 could be removed from the head to true up any warping. No machine shop. A while back I milled off (if I remember correctly) .0625. I used a 1/2 inch end mill in my drill press and it took damn near forever.

I have never used this head and, of course, the engine is just a trial and error project for me so if it causes problems, I will substitute another.

 

[tater76]

Re: Second Generation Chrysler

Thought you might say that. You must have one hell of a drill press, My LORD that would take forever! I burned out my 10 year old unit after trying to mill for roughly 15 mins. Must have been the bearing or gears in the head unit. Guess thats what I get for buying cheap and using a tool that is designed to go up and down with no side pressure. As for the .010, I have been told this will not increase pressure, at least not enough to notice/harm anything. I had a 200cc 4 wheeler when I was a kid, had the head milled something like .0800 if I remember right. It was a PITA to kick over, but ran like an animal.

On another note, are you going to do the racing exhaust? I've heard you talk about building the stainless seperator, and don't think it would be that difficult in the right hands? Either way I can't wait to hear how it all works out.