I don't know what year they started using the nylon timing gears, but I know of a 1970 318 that had one that was bad enough to allow the timing chain to skip a few teeth and bend valves and pushrods.
Please help me diagnose this 273
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I don't know what year they started using the nylon timing gears, but I know of a 1970 318 that had one that was bad enough to allow the timing chain to skip a few teeth and bend valves and pushrods.
It happens. I think the nylon coated gears were one of the stupidest things ever. It was all a quest to make the engine more quiet, but I've never in my life heard steel chain and sprockets make noise........unless they were so worn the chain slapped the timing cover.......I have seen that more than once. One on my own 3.8 Buick V6 I had in a 76 Olds Starfire. It hit the cover for so long and so bad that it wore a hole in it. I was waiting for it to wear out, because I slammed a Chevy 400 in it after that. lol
Not sure what you are trying to say, but it sounds snarky. When you make statements that are untrue, other readers realize that you are just being argumentative, and this hurts your credibility in the future.
For those who like to learn about some of the old Mopar history, go to ALLPAR.com, type in "dyno testing" and search for an article by Ed Poplawski. He ran some of the dynos back in the 60's and 70's. He also ran dyno #13, which was used for high performance engine testing. There is also some interesting photos of the dyno rooms [they called them cells]. With all the tubes and wires hanging off, the engines look like they are on life support.
well back in the day I asked my step father what was different between a truck engine and a car engine and knowing everything he told me they tested them all and the good ones went into cars and the rest into trucks because they didn't need much power because they had all the gears to shift, and my first real job as a mechanic was working on light duty trucks ,boy he sure was wrong.
Facinating article. Reading it now. Thanks for the info!
nm9stheham
Well-Known Member
That is excellent! Good deal! So now to see why you have some spark plug oiling....Are you able to drive it around now?
The PO jacked up the kickdown linkage when he did the manifold/carb swap, so no, I haven’t driven it much. I did drive it around the block very slowly to make sure it wouldn’t die. I have a Bouschillon kickdown setup I’ll be installing in the next couple days and then I should be driving.
Any thoughts on the spark plug oiling?
nm9stheham
Well-Known Member
IMHO... could be ring and/or bore wear. Your compression is up now, but there are limits to what that can tell you. If a cylinder is oiling, the compression is going to look good even with considerable wear as the oil will help seal the rings. (Now if the ring/bore wear is really bad, then then even that won't happen.)
Valve stem seals are the other typical spot and that would not be unusual in an engine that old. The valve stem seals are shot/gone. Not all that hard to replace with the engine in the car.. a very common procedure. It won't fix worn rings/bores, but it is easy enough to do that it makes sense to try.
Once you get it ti driving around, then there are observations you can make that can point you to one of these issues or the other.
Valve stem seals are the other typical spot and that would not be unusual in an engine that old. The valve stem seals are shot/gone. Not all that hard to replace with the engine in the car.. a very common procedure. It won't fix worn rings/bores, but it is easy enough to do that it makes sense to try.
Once you get it ti driving around, then there are observations you can make that can point you to one of these issues or the other.
If it puffs blue smoke when you start it, that is valve stem seals, as mentioned above, not a terribly difficult job to change in the car. If it smokes when driving, the rings could be worn or need to reseat if it has been sitting a long time.
If the intake valve was way out of adjustment and not opening much it will suck oil up around the rings, plus you don't have a good fire on that cyl to burn off the oil.
Has the op changed plugs yet?
Plugs have been changed. I bought Champions, but some were damaged right out of the box, so I replaced them with Autolites. It was a little sad to see that they’re made in China now, but not entirely surprising. Oh well, they’ll do until I can get some nos champions on eBay or maybe just some NGKs.
Absolutely not. I am speaking from experience, not an online article. It's a well known fact that Chrysler engines all through the muscle car era were well under their rated compression ratios, due to high deck heights, large combustion chambers, retarded camshaft timing and tuning that "could have been better". I am very familiar with the Allpar article and many more. Those dyno tests were only run on select few engines that were tuned specifically for those dyno runs. That hardly represents the entire Chrysler engine lineup. Everything I have listed here is well known through the Mopar community as fact. I don't care what Allpar says. That one article certainly doesn't speak for the vast majority of Chrysler engines that were produced. Ask any competent machinist that's been around 40 years or more. They can well attest to the facts regarding Chrysler's lack of tolerance with factory machine work. It was all over the map. Nothing I've said was untrue. Snarky........maybe a little. That's what big girl pants are for.
We regularly ran the head decks on the block and heads on the fat side so if we had a tear down engine to recycle parts off of and the head faces got scratched/damaged, we would separate them and batch run them and re-mill the face to clean them up and re-use them.... We would take advantage of downtime on the front end of the machining line to batch run them on the head/block face mill operation...
I've read this elsewhere, Karl. It does have advantages with production work as far as a "cushion" for mistakes and the like. I just find it humorous anyone would actually believe every Chrysler engine was dyno tuned for max performance. lol
No, they weren't dyno tuned...
I know from talking to some old timers that they used to have engine run "hot test stands" at the end of the big block assembly lines where they would start them and run them for a short time 1 minute give or take to make sure they ran and to prime the oil system... Some people may have twisted that into saying that they were dyno tested...
They said that if the 440 6 pack engines were set too advanced they would shoot flames out of the center carb up to the roof... So sometimes the operators used to advance the distributors on them on purpose to see the "flame show"... You could see it from halfway down the assembly line...
When I was there we used a cold test stands after the long block was assembled and they spun the engine without firing it to prime the oil system and check valve timing events and oil pattern... They would fill it with oil, and could catch a rod with a plugged squirt hole, and see if the valves were opening and closing at the right time, and soft lifters, spark timing, gap on spark plugs (they could catch a closed gap), malfunctioning or improperly installed cam and crank sensors would also be caught... All information was stored in a database linked to the bar code on the valve cover for ID.... It was more advanced than starting an engine on the old style hot test stands... If anything was found wrong, they had cold test repair men that would repair the problem and then it would be retested until it could pass... If it couldn't pass the cold test, it would not be allowed to leave the cold test stand loop and taken off the line to be sent to the tear down department to be torn down and any good parts recycled... Cold test dtands were basically dyno stands the spun the engine over without starting it...
We also audited engines on a regular basis... One of each size engine that we made was put on a hot test stand in the audit department every day and ran for about 30 minutes, then torn down and inspected... Any defects found were rated on a scale of 1 - 10 with 10 being the worst... If we got a 10 demerit in audit, we had to immediately see what failed and report how it happened and how we could prevent it from happening within 24 hours of the failed audit... Then determine if any other engines made since the last audit could have that defect and quarantine them to be inspected to verify that they didn't have that defect before we were allowed to ship them... If not, we had to scrap them and tear them down and recycle any good parts...
Then the dyno lab in the factory would test one of each engine per week on an engine dyno for 10 hours... They had a program to run them at different RPM's some of which were acceleration from idle to max and another part was to do 30 minutes of wide open throttle... After the dyno test, the dyno lab techs would verify the torque on all fasteners on the engine while tearing it down and then inspecting it for wear... The horsepower and torque curves were then distributed to all engineers and managers at the engine plant and the design center every week...
All of the audit and dyno test engines were torn down and some of the parts were recycled and others were scrapped... They used natural gas to run them instead of gas because the natural gas was "dry" and we could recycle the fuel injectors etc after that instead of having to scrap them and treat them as hazardous material if they came in contact with 'wet' gas...
If we had to scrap all of the engine parts that were torn down and got some scratches on the deck faces, it would get very costly... So you run them fat so there is meat on there to do a skim mill on those faces to clean them up and make them good again... You run them to the high side of the tolerance spec so you can mill them and be in the middle or low end of the spec and still be usable...
They are only allowed to vary 1 compression point in production... If they run more than one compression point for variation it is a federal emissions violation which can lead to a recall and re-certification if caught...
Yeah but that doesn't explain why the decks were crooked as hell. Alcohol maybe? lol
Casting variation, the machine operator not making the proper adjustments on the line, or sometimes they didn't want to shut down the line and make the adjustment and loose production...
If they were running tight on parts and could not afford to shut the line down to make the adjustments, the managers that ran the line... No matter what us engineers said, we were overridden by the managers who had to report to the plant manager and he had to report to the executives in the headquarters why their production numbers were low...
If we couldn't make enough engines and shut down an assembly plant, somebody's *** was on the hot seat...
However we usually tried to build ahead and have a bank of engines as a buffer... But even then, downtime on the lines is looked down upon... Every line has it's production volume that they are expected to meet every day...
All production numbers were reported to the execs in the headquarters every day and they had to justify why they didn't meet their daily targets...
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There is another article about the birth of the 426 hemi and how they put it on a dyno before it was supposed to run at its first nascar race. After running it at full power it blew out webs in the block. So they had thicker webs cast into the block, machined it, and had it ready to race, just in time. Amazing what can be done when priorities are given to accomplish certain goals.
Even you can understand why I believe a technician who actually ran the dynos in the test cells in the 60's and 70's rather than believe an experienced typist.
What years did you work there?
It is probably intake valve seals. They are probably long gone. Get some Viton positive seals like Mopar Performance or Fel-Pro. Get everything up to par, change oil to Valvoline racing 20w50 and a good filter and see if the oil consumption goes way down.
Congratulations. You made the cut. ;)
The story that I heard was that Richard Petty broke his block in testing before the first race... They identified the weak spots and beefed them up... Then cast his new block two weeks before the race and he won with that engine...
Richard Petty won the debut race for the Hemi with a fresh prototype block which is amazing...
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