383 project: The tear-down

[ACME A12]

Buy a cheapie 1" travel indicator with a magnetic base. You'll need this for other tasks down the line anyway.

:yesnod: :yesnod: :yesnod:

 

[Big John]

Speaking of crankshaft thrust surfaces, I had a problem with one back in the 70's that drove me crazy.

I built an engine for the race car and the first time out, the car just fell on it's face. It kept going slower and it was obvious there was something wrong internally. I pulled the engine apart and the thrust surface of the crank was smoked along with the bearing torn apart. I talked to a bunch of people and the opinion was it was just a bad crank. Tried it again with the same results.

Changed the block and crank for the next try. Same result! By now, I saw the trans was smoked. Changed the crank and the torque convertor and had the trans rebuilt by someone else... another crank hit the scrap pile.

I called Turbo Action, the maker of the convertors and my valve body...... he said "geez, it could be a line pressure problem... but... that would be the valve body"

The valve body was the piece that was common to everything. I pulled the trans apart and the thrust washer in there was toast but everything else was good. I put a different valve body in the trans and, of course, a new crankshaft, and that solved the problem.

That cost me a ton of $$, a lot of frustration and most of the racing season that year.

 

[69hemibeep]

Hyper pistons are tough as nails, they require different clearances so the choice will need to be made after the machinist checks the block for size. There are allot of wives tales out there about hyper pistons. I use them and a friend has been using them in a twin turbo rig and breaks everything but the pistons. Any personal experience guys?

 

[sixgunrunner68]

Hyper pistons are tough as nails, they require different clearances so the choice will need to be made after the machinist checks the block for size. There are allot of wives tales out there about hyper pistons. I use them and a friend has been using them in a twin turbo rig and breaks everything but the pistons. Any personal experience guys?

I'm running KB hypers in mine, so far so good. For a street car there shouldn't be any issues, if you were going to pounding on it at the track every weekend then forged is the way to go. :cents: The tolerances are tighter on the hypers since there is less thermal expansion than forged units.
As far as purple shafts. I'm running one of those too. The solid .528"/284 adv.dur. While I do agree with Ray that there are a lot of choices out there now, and if I were to do it again, I'd explore them. Call the cam manufacturer and explain your goals so they can point you in the right direction, don't wing it.
That being said, d.c. cams were designed for these engines. They worked then and they work now. If you were to choose one, I doubt you'd be dissappointed. The old Direct Connection engine book has all the different recipes for them listed.

 

[ACME A12]

They have also had some well documented quality control issues in recent years, Marty. Search the web. You'll find plenty of horror stories about them being incorrectly ground. I have a nice one out in the garage that is very useful as a door stop so I have some VERY PERSONAL experience in this arena. It set me back weeks/months in terms of engine development and having a driveable car. I would HATE to see a novice engine builder stuck trying to figure out why his brand new engine runs like SH*T when the cam is at fault. I don't have an axe to grind with them, and one of my favorite flat tappet solids of all-time was a Purple Shaft (it was one of the old, good ones engineered by Racer Brown himself) back in the day, but times and technology have moved on. Harold Brookshire designed the Voodoo cams for Lunati and he has stated many times that their MoPar offerings were designed around the .904" lifter diameter. Comp claims the same for the XE line. Same for Hughes as they are MoPar specific. After what I went through with the stroker in the wife's Swinger the old DC's are off of my play list...

No one I know refuses to get a new cell phone, or LED/LCD TV, or DVR, or GPS because they do not want to take advantage of the latest in available technology; why people want to hang on to 30+ year old cam designs just befuddles the piss out of me... I like to have a map in the glove box just as much as the next guy, but you can bet your ass that my GPS is already sitting up on the dash board...

:jester:


BTW - I posted a link to a Q&A with Harold on here some time ago, as well as a comparison between the Voodoos and the XEs. Voodoos made more power. Probably only because Harold hates Comp so much for what they did to his business that he made sure that they did... Anyway, search for Harold Brookshire on here and I'm sure it will pop up - if you're interested.

 

[ACME A12]

Speaking of crankshaft thrust surfaces, I had a problem with one back in the 70's that drove me crazy.

I built an engine for the race car and the first time out, the car just fell on it's face. It kept going slower and it was obvious there was something wrong internally. I pulled the engine apart and the thrust surface of the crank was smoked along with the bearing torn apart. I talked to a bunch of people and the opinion was it was just a bad crank. Tried it again with the same results.

Changed the block and crank for the next try. Same result! By now, I saw the trans was smoked. Changed the crank and the torque convertor and had the trans rebuilt by someone else... another crank hit the scrap pile.

I called Turbo Action, the maker of the convertors and my valve body...... he said "geez, it could be a line pressure problem... but... that would be the valve body"

The valve body was the piece that was common to everything. I pulled the trans apart and the thrust washer in there was toast but everything else was good. I put a different valve body in the trans and, of course, a new crankshaft, and that solved the problem.

That cost me a ton of $$, a lot of frustration and most of the racing season that year.

Did you dissect the valve body to see what was going on? Just curious...

 

[69hemibeep]

I'm a fan of Comp and Lunati also, remember its better to go a little small on a cam than a little to big. A friend of mine bought a 502 chevy crate mtr slipped in a larger cam to make it better now he's added a larger injection system and upping the compression to make the cam work. we as a group had an intervention with him to put a smaller cam in because he had no intentions of doing all this, but he's dead set to prove the cam is not to big :loco: :lmao: :lmao:

 

[sixgunrunner68]

Ray, I wasn't aware of the qc issues. I bought mine in '94 so maybe I got lucky. All I'm trying to say though is that they do work, provided they're ground correctly I guess. But like I said, I would explore the newer options if and when the time comes. I'm on the same page with ya Ray.

 

[Big John]

[quote="Big John":11pmi656]Speaking of crankshaft thrust surfaces, I had a problem with one back in the 70's that drove me crazy.

I built an engine for the race car and the first time out, the car just fell on it's face. It kept going slower and it was obvious there was something wrong internally. I pulled the engine apart and the thrust surface of the crank was smoked along with the bearing torn apart. I talked to a bunch of people and the opinion was it was just a bad crank. Tried it again with the same results.

Changed the block and crank for the next try. Same result! By now, I saw the trans was smoked. Changed the crank and the torque convertor and had the trans rebuilt by someone else... another crank hit the scrap pile.

I called Turbo Action, the maker of the convertors and my valve body...... he said "geez, it could be a line pressure problem... but... that would be the valve body"

The valve body was the piece that was common to everything. I pulled the trans apart and the thrust washer in there was toast but everything else was good. I put a different valve body in the trans and, of course, a new crankshaft, and that solved the problem.

That cost me a ton of $$, a lot of frustration and most of the racing season that year.

Did you dissect the valve body to see what was going on? Just curious... [/quote:11pmi656]

I did, but didn't find the problem as I really didn't know what mods were done to the valve body. This was a fairly new product at the time, a "Cheetah" valve body that eliminated most of the 2-3 overlap in the shift. That was a real issue in the automatic cars at the time.... probably worth a tenth or so in a lot of cars. I had spoke to Paul Forte at Turbo Action and was going to return the valve body as he wanted to look at it, but never got around to it. The valve body hit the trash during a shop cleanout.

 

[ACME A12]

I'm a fan of Comp and Lunati also, remember its better to go a little small on a cam than a little to big. A friend of mine bought a 502 chevy crate mtr slipped in a larger cam to make it better now he's added a larger injection system and upping the compression to make the cam work. we as a group had an intervention with him to put a smaller cam in because he had no intentions of doing all this, but he's dead set to prove the cam is not to big :loco: :lmao: :lmao:

Harry - DO NOT READ MY RESPONSE TO THIS POST!!!

Bob, I'm with your friend; there's no such thing as too much cam. That's an old wives tale... Now there are such things as not enough compression, not enough carburetion/injection, valves and ports that are too small, a convertor that is too tight, and not enough gear, but there is no such thing as too much cam!!! :lmao: :lmao: :lmao:

Harry - we now return you to your regular scheduled programming...

:jester:

 

[mcmopar]

I'm a fan of Comp and Lunati also, remember its better to go a little small on a cam than a little to big. A friend of mine bought a 502 chevy crate mtr slipped in a larger cam to make it better now he's added a larger injection system and upping the compression to make the cam work. we as a group had an intervention with him to put a smaller cam in because he had no intentions of doing all this, but he's dead set to prove the cam is not to big :loco: :lmao: :lmao:

Harry - DO NOT READ MY RESPONSE TO THIS POST!!!

Bob, I'm with your friend; there's no such thing as too much cam. That's an old wives tale... Now there are such things as not enough compression, not enough carburetion/injection, valves and ports that are too small, a convertor that is too tight, and not enough gear, but there is no such thing as too much cam!!! :lmao: :lmao: :lmao:

Harry - we now return you to your regular scheduled programming...

:jester:

I'm with Ray concerning cam selection. Hughes, Comp, Lunati are all good choices. I would also HIGHLY recommend a new, hardened fuel pump pushrod. Hughes used to have them. A few of us on this very board have replaced our cams only to have the original fuel pump pushrod grind itself to powder inside our engines. Its the little things that kill your engine and this is one of them.
As for hypereutetic pistons - I'm far from sold on them. A number of years ago one of the piston manufacturers did a comparison between hypers and forged. The hypers lost BADLY when it came to compressive strength and durability. Of course, time and technology marches on and improvements have probably been made in the hypers but I don't trust them. I'd prefer a set of cast pistons over the hypers personally, but that's just my :cents: on the matter. If you want ultimate strength - go forged.

 

[69hemibeep]

I'm a fan of Comp and Lunati also, remember its better to go a little small on a cam than a little to big. A friend of mine bought a 502 chevy crate mtr slipped in a larger cam to make it better now he's added a larger injection system and upping the compression to make the cam work. we as a group had an intervention with him to put a smaller cam in because he had no intentions of doing all this, but he's dead set to prove the cam is not to big :loco: :lmao: :lmao:

Harry - DO NOT READ MY RESPONSE TO THIS POST!!!

Bob, I'm with your friend; there's no such thing as too much cam. That's an old wives tale... Now there are such things as not enough compression, not enough carburetion/injection, valves and ports that are too small, a convertor that is too tight, and not enough gear, but there is no such thing as too much cam!!! :lmao: :lmao: :lmao:

Harry - we now return you to your regular scheduled programming...

:jester:

How about too much cam for the intended use of the equipment :toetap:

 

[69hemibeep]

Here is part of an article on pistons---A hypereutectic piston is an internal combustion engine piston cast using a hypereutectic alloy–that is, a metallic alloy which has a composition beyond the eutectic point. Hypereutectic pistons are made of an aluminum alloy which has much more silicon present than is soluble in aluminum at the operating temperature. Hypereutectic aluminum has a lower coefficient of thermal expansion, which allows engine designers to specify much tighter tolerances.

The most common material used for automotive pistons is aluminum due to its light weight, low cost, and acceptable strength. Although other elements may be present in smaller amounts, the alloying element of concern in aluminum for pistons is silicon. The point at which silicon is fully and exactly soluble in aluminum at operating temperatures is around 12%. Either more or less silicon than this will result in two separate phases in the solidified crystal structure of the metal. This is very common. When significantly more silicon is added to the aluminum than 12%, the properties of the aluminum change in a way that is useful for the purposes of pistons for combustion engines. However, at a blend of 25% silicon there is a significant reduction of strength in the metal, so hypereutectic pistons commonly use a level of silicon between 16% and 19%. Special moulds, casting, and cooling techniques are required to obtain uniformly dispersed silicon particles throughout the piston material.

Hypereutectic pistons are stronger than more common cast aluminum pistons and used in many high performance applications. They are not as strong as forged pistons, but are much lower cost due to being cast.
[edit] Advantages

Most automotive engines use aluminium pistons that move in an iron cylinder. The average temperature of a piston crown in a gasoline engine during normal operation is typically about 300 °C (570 °F), and the coolant that runs through the engine block is usually regulated at approximately 90 °C (190 °F). Aluminium expands more than iron at this temperature range, so for the piston to fit the cylinder properly when at a normal operating temperature, the piston must have a loose fit when cold.

In the 1970s, increasing concern over exhaust pollution caused the U.S. government to form the Environmental Protection Agency (EPA), which began passing legislation that forced automobile manufacturers to introduce changes that made their engines run cleaner. By the late 1980s, automobile exhaust pollution had been noticeably improved, but more stringent regulations forced car manufacturers to adopt the use of electronically controlled fuel injection and hypereutectic pistons. Regarding pistons, it was discovered that when an engine was cold during start-up, a small amount of fuel became trapped between the piston rings. As the engine warmed up, the piston expanded and expelled this small amount of fuel which added to the amount of unburnt hydrocarbons in the exhaust.

By adding silicon to the piston's alloy, the piston expansion was dramatically reduced. This allowed engineers to specify a much tighter cold-fit between the piston and the cylinder liner. Silicon itself expands less than aluminium, but it also acts as an insulator to prevent the aluminium from absorbing as much of the operational heat as it otherwise would. Another benefit of adding silicon is that the piston becomes harder and is less susceptible to scuffing which can occur when a soft aluminium piston is cold-revved in a relatively dry cylinder on start-up or during abnormally high operating temperatures.

The biggest drawback of adding silicon to pistons is that the piston becomes more brittle as the ratio of silicon is added. This makes the piston more susceptible to cracking if the engine experiences pre-ignition or detonation.
[edit] Performance replacement alloys

When auto enthusiasts want to increase the power of the engine, they may add some type of forced induction. By compressing more air and fuel into each intake cycle, the power of the engine can be dramatically increased. This also increases the heat and pressure in the cylinder.

The normal temperature of gasoline engine exhaust is approximately 650 °C (1,200 °F). This is also approximately the melting point of most aluminum alloys and it is only the constant influx of ambient air that prevents the piston from deforming and failing. Forced induction increases the operating temperatures while "under boost", and if the excess heat is added faster than engine can shed it, the elevated cylinder temperatures will cause the air and fuel mix to auto-ignite on the compression stroke before the spark event. This is one type of engine knocking that causes a sudden shockwave and pressure spike, which can result in an immediate and catastrophic failure of the piston and connecting rod.[citation needed]

The "4032" performance piston alloy has a silicon content of approximately 11%. This means that it expands less than a piston with no silicon, but since the silicon is fully alloyed on a molecular level (eutectic), the alloy is less brittle and more flexible than a stock hypereutectic "smog"[clarification needed] piston. These pistons can survive mild detonation with less damage than stock pistons.

 

[ACME A12]

I'm a fan of Comp and Lunati also, remember its better to go a little small on a cam than a little to big. A friend of mine bought a 502 chevy crate mtr slipped in a larger cam to make it better now he's added a larger injection system and upping the compression to make the cam work. we as a group had an intervention with him to put a smaller cam in because he had no intentions of doing all this, but he's dead set to prove the cam is not to big :loco: :lmao: :lmao:

Harry - DO NOT READ MY RESPONSE TO THIS POST!!!

Bob, I'm with your friend; there's no such thing as too much cam. That's an old wives tale... Now there are such things as not enough compression, not enough carburetion/injection, valves and ports that are too small, a convertor that is too tight, and not enough gear, but there is no such thing as too much cam!!! :lmao: :lmao: :lmao:

Harry - we now return you to your regular scheduled programming...

:jester:

How about too much cam for the intended use of the equipment :toetap:

Well of course...which is why I told Harry to ignore my antics. I was just being funny...or trying anyway...

There's nothing worse than mis-matched engine components...They will ruin your day. :yesnod:

 

[ACME A12]

Hypereutectic aluminum has a lower coefficient of thermal expansion, which allows engine designers to specify much tighter tolerances.

Which is why I told Harry to follow the Manufacturer's recommendations for clearances for whatever he ends up with.

 

[Jim S.]

I'm with Ray concerning cam selection. Hughes, Comp, Lunati are all good choices. I would also HIGHLY recommend a new, hardened fuel pump pushrod. Hughes used to have them. A few of us on this very board have replaced our cams only to have the original fuel pump pushrod grind itself to powder inside our engines. Its the little things that kill your engine and this is one of them.
As for hypereutetic pistons - I'm far from sold on them. A number of years ago one of the piston manufacturers did a comparison between hypers and forged. The hypers lost BADLY when it came to compressive strength and durability. Of course, time and technology marches on and improvements have probably been made in the hypers but I don't trust them. I'd prefer a set of cast pistons over the hypers personally, but that's just my :cents: on the matter. If you want ultimate strength - go forged.[/quote]


Hughes engines has the hardened fuel pump push rods again, got one last week...

 

[moparchris]

I ran a 350 shot of the giggle juice on my Hypers. Got over 150 passes on them in my low 10 second car no problems. That is until the Fuel solenoid stuck closed and the motor ingested pure nitrous, even only for a second it smoked 6 out of 8 pistons. I still love them.


I have also ran Mopar cams and I built a 440 with a MP .528 which made over 500 hp. Great cam. I have yet to have any QC issues with MP but Comp on the other hand. Well, I just dont want to get into it more than I have personally seen more than a dozen Comp cams ground wrong or even bent! I am a firm believer that Comp has BIG issues with their QC. There customer service when something does go wrong is THE WORST!!!! Buyer beware. :cents:

 

[69hemibeep]

Harry - DO NOT READ MY RESPONSE TO THIS POST!!!

Bob, I'm with your friend; there's no such thing as too much cam. That's an old wives tale... Now there are such things as not enough compression, not enough carburetion/injection, valves and ports that are too small, a convertor that is too tight, and not enough gear, but there is no such thing as too much cam!!! :lmao: :lmao: :lmao:

Harry - we now return you to your regular scheduled programming...

:jester:[/quote]
How about too much cam for the intended use of the equipment :toetap:[/quote]

Well of course...which is why I told Harry to ignore my antics. I was just being funny...or trying anyway...

There's nothing worse than mis-matched engine components...They will ruin your day. :yesnod:[/quote]
Oh, you are funny :acme:

 

[roadrunnerh]

I've been reading my Mopar Chassis Book that contains several engine set-ups.

I know what you guys mean regarding the cam choices people make and going with too much cam.
According to this mopar book, 484 cam seems up my alley - whether or not I go with that one is another story. From what I have read here and elsewhere, I too have some concerns about Mopar Performance parts in the past ten years or so.

 

[ACME A12]

I have yet to have any QC issues with MP but Comp on the other hand. Well, I just dont want to get into it more than I have personally seen more than a dozen Comp cams ground wrong or even bent! I am a firm believer that Comp has BIG issues with their QC. There customer service when something does go wrong is THE WORST!!!! Buyer beware. :cents:

Boy, they had their hands full a few years ago when all of their beehive springs went to sh*t...that's for sure. I was never a fan of the concept anyway... :leave:

Probably just Karma getting even with them for the evil sh*t that they pulled on Harold and Ultradyne... :yesnod: :yesnod:

:jester: