Comp cams xe268h for 318

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If want to try to save it, wipe those out 100%, wipe some ATF in there and move up and down, and then repeat over and over, continuously wiping. You need to get all the crap out, even down by the rings as much as you can. It'll wear on the walls in a hurry; iron oxide is an abrasive material.

If the deck height is right, that is mighty good. What measuring device did you use? I thought this was not a Magnum?? No stock aftermarket replacement pistons that I am aware of are that high up. It WOULD be nice!
 
nm9stheham said:
If want to try to save it, wipe those out 100%, wipe some ATF in there and move up and down, and then repeat over and over, continuously wiping. You need to get all the crap out, even down by the rings as much as you can. It'll wear on the walls in a hurry; iron oxide is an abrasive material.

If the deck height is right, that is mighty good. What measuring device did you use? I thought this was not a Magnum?? No stock aftermarket replacement pistons that I am aware of are that high up. It WOULD be nice!
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Yea it's rough its gotta come out I'm looking into diy honing. I'm thinking maybe trying some 600-1000 sand paper and polish it out I guess as much as I didnt want to I'm gonna go ahead and pull the crank and pistons. And go from there. Looks like it needs hot tanked there is alot of rust in the water jackets. I used a reloading caliper to measure I'm gonna measure again tomorrow and double check with a straight edge. Like I said I was fighting mosquitoes and was in a hurry lol. I will try and get the head cced in the next day or two. I'm really concerned about the block now. I'm kinda at a point where it may be better financially to just start the 360 build. If I have to do machine work on this block I might as well do it on the 360.
 
nm9stheham said:
Or higher actual compression ratio..... Was that a later production 340, like a late '72 or a '73?
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Agree with Mike seen it too many times cam duration one or two sizes too big for the application/ current build
we had that "coming up on the cam" in the XKE with the ISKY XM-3 (or XM-2 on the intake and XM-3 on the exhaust which was better
you tried to keep the rpm above the power tip in point but if you went below you were dead and if they came on on a curve you could loose it
so a rant
Comp XE268 was a great cam- state of the art in 1977 when the Late Harold Berkshire designed it- before Ultradyne and after General Kenetics
The stock 340 cam and the 340 stick shift cam have their 50 year anniversary this year (the stick lobes may be borrowed and even older)
I think these were Camcraft designs- the older gentleman there, I'm forgetting his name- did great work
But what computers were available in 1967? How many degrees between lift data points, and smooth with a file/ stone and an optical comparative system
That's the way it was with most till Harvey Crane publicized his "computer smoothing" program, and tough in cheek offered to smooth other grinders profiles.
Today you can have a CNC grinder grind from a computer file with no master getting in the way and adding a layer of error with CNC accuracy on your lift table and degrees
Rick Jones is doing this- you get to pick your grinder

So why does the 340 and 330 Magnum cam have such long (and high) closing ramps?
Warranties
exhaust valve seat recesion was appearing and the long ramp allowed the lifter to not make noise
later it became an exhaust gas dilution feature
no matter- neither are things that are needed in today's performance build- just compromises that hurt your results
no way around the dynamic compression hit or the excess overlap/ heat
 
nm9stheham said:
I gotta root around Wyrm's info on how the factory actually measured 'advertised'....IIRC it was at .008" lift??
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They drew lines on the drawings of the cam profile to locate where the ramp changes.

There's a few posts on Speedtalk about this. In one someone posted (not Wyrm) finding them to equal to between .007 to .011[?] lift at the valve. Argh. can't find that post now.
Here's one with Wyrmriders explanation, top of page 2: Degreeing a camshaft for begginners - Speed Talk
I think one of the points here is that the MP advertised duration is a measurement on the cam, rather a measurement at the valve. Maybe the FSM too - need to pull one off the shelf and see how they expect the number to be used, if at all, for repair purposes.
@Wyrmrider If you still have those cam doctor profiles, it would be really cool to with the FSM and Mopar performance published data.
 
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dartfreak75 said:
I'm not sure how this happened because the engine has been inside covered in a tarp for the last seven years before that it was driven daily.
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Condensation. :(
Air carries moisture. Warm air can carry more than cold. On cool nights the temperature of the engine metal dropped below the dew point of the air inside. Tarp doesn't protect against that. :(
However its an important principle to keep in mind: The amount of moisture held in air is dependent on pressure and temperature. That applies to fuel as well as water and so applies to wet intake manifolds when they go from low pressure to high. Just tuck that away for now. :)
 
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Mattax said:
Condensation. :(
Air carries moisture. Warm air can carry more than cold. On cool nights the temperature of the engine metal dropped below the dew point of the air inside. Tarp doesn't protect against that. :(
However its an important principle to keep in mind: The amount of moisture held in air is dependent on pressure and temperature. That applies to fuel as well as water and so applies to wet intake manifolds when they go from low pressure to high. Just tuck that away for now. :)
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Yea that's what I was thinking also. I also think it may have been more my fault also. More on that later.
I researched alot last night and i have came up with a plan. I ordered a cylinder bore hone and some measuring tools. I'm gonna try to clean the bores out if I can I'm gonna rering I try and run it. If not I'm just gonna scrape the hole plan and just build the 360 I have now! Its gonna take longer cause I dont have the money but I'm just focus on the rest of the car and get everything done that I can and keep saving up. That's probably gonna be another year or two lol. I really hope I can clean the bores up. I'm gonna pull the other head today and spray some oil in there Hopefully that will help stop it
 
I do have them but I'm moving after 35 years- wife's been here since 55
Krooser I'll still have same phone and e-mail
I have 15 hard drives that I'm trying to pull the relevant data off of...
only thing I have handy right now is the early DC 260 and the Jones Hyd with .305 lobe lift- one of my favorites
yes mopar timing and durations are taken from the blueprint I use .008 because it's usually close and the same as Engle but some could be .011
Mopar is consistent so you can compare OEM/FSM and DC but not useful for much else

Dart use hone oil you can use a rust remover like clr but neutralize with baking soda
If you know someone with a caustic hot tank that would work but would require new cam bearings
worse have been honed and run for a long time
did I say I used to have several used car dealers for customers???
 
I got the other side off it does not look as bad it looks pretty good compared. I also dug my old 360 out of the building it looks about the same honestly. So now I'm considering just scraping the whole 318 and just building the 360. If honing will fix one it will fix the other so why not right? Idk what I gonna do yet decisions decisions!!! There is a slight ridge in the 360 that is not there in the 318 so it may need bored idk. Can you hone out a ridge without boring? Or will it remove to much material for STD pistons? On a good note I got some suspension parts painted. Here are some pics 318 vs 360.

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if you could get a good deck hight reading on that 318 and when you pull a piston a good comprission hight,..that would be great!! DWB
 
dartfreak75 said:
So you dont think honing will clean either one of them??
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Rust and corrosion is not good. Ridge isn't as big of a issue as taper is. I have never wasted time with a hone where a boring bar is needed. I know it costs $$$ but if you are going to half *** it you might as well find a junkyard motor and roll the dice.
 
toolmanmike said:
Rust and corrosion is not good. Ridge isn't as big of a issue as taper is. I have never wasted time with a hone where a boring bar is needed. I know it costs $$$ but if you are going to half *** it you might as well find a junkyard motor and roll the dice.
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Wow your in quite a mood today!! Lol :poke:
 
dartfreak75 said:
Ask and you shall receive I have a thread in the members restoration section please check it out if you want. I started with 1000$ I started with the safety stuff new brakes new bushings ball joints steering gear basically everything suspension steering and brakes is new! Iv got new wheels and tires (not installed yet obviously) new leaf springs etc. Well that took more than I expected so ran into problems indidnt expect I had to replace my lcas and torsion bars. Anyways long story. I'm now about 1500 in.

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Build the car then build the powerplant.
 
That .067, on flat-tops would be pushing 13cc then, and over .100 Quench. But that little dish on the crown is gonna throw several more cc's at the Total volume.
 
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AJ/FormS said:
That .067, on flat-tops would be pushing 13cc then, and over .100 Quench. But that little dish on the crown is gonna throw several more cc's at the Total volume.
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Meaning??? It dont have a dish. It does have a crown I thought all pistons had that.
 
late 318 pistons have a depression in the center, which is called a dish. at .022 deep that may be 3cc's
adding it all up; 13+3+8.6gasket+63heads=87.6cc and at stock 3.91 bore this maths out to 8.45SCr......... not too bad, in theory.
Even if the dish is 6cc, you are still at 8.2
Just don't put police heads on to get 7.2....or less
 
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