That certainly makes sense as many other inconsistencies as there are across the board with Mopar. Thanks, Jim!
400/450 stroker....Cheap parts, lotta work.
- Thread starter IQ52
- Start date
-
That certainly makes sense as many other inconsistencies as there are across the board with Mopar. Thanks, Jim!
Can you make some room in your message box please? I have somethin I would like your opinion on.
All clear......took me awhile to figure out how to clear stuff out.
Thank you drive through. Incoming.
When we first cc'd the combustion chambers in the 346 heads we got column #1. Then we had the heads milled and we machined the combustion chamber flats to .110" deep and got column #2.
1) cc's........2) cc's
88.4...........87.7
89.0...........88.8
90.1...........89.1
89.6...........88.4
89.0...........88.8
89.6...........88.8
90.2...........89.6
88.8...........87.8
If you've ever tried to equal out the combustion chambers by grinding on them you know what a pain in the pahtoot it is.
Never-the-less we got out the digital programmer (on the left in the photo) and the CNC machine (on the right) and made one pass through the smallest chambers.
And ended up with these results......................
88.8
88.8
89.1
88.6
88.8
88.8
89.6 I'm not willing to spend the time to grind all the chambers out this big!
88.6
The compression ratio will vary from 10.06:1 @ 89.6 cc's to10.15:1 @ 88.6 cc's Good enough for this engine!
1) cc's........2) cc's
88.4...........87.7
89.0...........88.8
90.1...........89.1
89.6...........88.4
89.0...........88.8
89.6...........88.8
90.2...........89.6
88.8...........87.8
If you've ever tried to equal out the combustion chambers by grinding on them you know what a pain in the pahtoot it is.
Never-the-less we got out the digital programmer (on the left in the photo) and the CNC machine (on the right) and made one pass through the smallest chambers.
And ended up with these results......................
88.8
88.8
89.1
88.6
88.8
88.8
89.6 I'm not willing to spend the time to grind all the chambers out this big!
88.6
The compression ratio will vary from 10.06:1 @ 89.6 cc's to10.15:1 @ 88.6 cc's Good enough for this engine!
Last edited:
And when the chambers/pistons carbon up, the numbers will change again....
Pontiac machined their chambers for equal volumes. What did it do v as cast chambers?
Nothing that I have seen documented that made any difference....
Pontiac machined their chambers for equal volumes. What did it do v as cast chambers?
Nothing that I have seen documented that made any difference....
Well thanks for your insight. We're just having fun here. I think I'll stick with the present plan and just see how this turd runs.
Probably run hard as turds on exit after a whole night of Tequila and tacos.
I'm sure it will have an effect on the climate here in Idaho.
We've been known to have violent pop-up thunder storms when you fire them builds up.
Thanks guys...yeah that and earthquakes.
Cody keeps upping his horsepower estimates. He's fondling his porting tools and eyeing the cylinder heads and intake manifold again. Down Boy...sit...stay!
EDIT: What the heck.... he's got the go ahead.
Last edited:
The rotating assembly went out for balancing so it's about time to look at some possible camshaft and timing set issues.
See the lobe that is below the lifter? Flat tappet cam cores are for the most part castings...and castings can have casting flash between the lobes. The manufacture should remove the flash between the lobes....sometimes this doesn't happen. This lobe is a potential lifter destroyer and could flatten the lobe itself. I have see where the casting flash doesn't get ground down as much as the lobe during the lobe grinding and because the lifter is wider than the lobe it hits that little flashing tit that sticks out to the left of the lobe. I've had to return two cams in the past years because of this defect.
To see if this is going to be a problem with this cam we set the cam in the block and used a test lifter to see if the dial indicator would jump as the lifter past by the flash. No movement.....so we're good to go.
After inspecting our cheapo $100 timing set we bought 6 years ago, we found that there were some burrs and proud metal between the rows of teeth on the cam gear. The timing chain was going to rub that crap off and deposit it into the engine oil....
Using our trusty ol' fine tooth files and brass vise jaw inserts we carefully removed the burrs and proud metal.
And we dropped the cleaned timing chain into a container of break-in oil to soak. Staying overnight in the oil bath and stirring it once in a while should get the chain safely pre-oiled. This chain will get really soaked because it going to set until the rotating assembly gets back from balancing later this week. I didn't soak one of my chains once and I ended up with a galled chain as stiff as a rusty bicycle chain after just a few dyno runs.
See the lobe that is below the lifter? Flat tappet cam cores are for the most part castings...and castings can have casting flash between the lobes. The manufacture should remove the flash between the lobes....sometimes this doesn't happen. This lobe is a potential lifter destroyer and could flatten the lobe itself. I have see where the casting flash doesn't get ground down as much as the lobe during the lobe grinding and because the lifter is wider than the lobe it hits that little flashing tit that sticks out to the left of the lobe. I've had to return two cams in the past years because of this defect.
To see if this is going to be a problem with this cam we set the cam in the block and used a test lifter to see if the dial indicator would jump as the lifter past by the flash. No movement.....so we're good to go.
After inspecting our cheapo $100 timing set we bought 6 years ago, we found that there were some burrs and proud metal between the rows of teeth on the cam gear. The timing chain was going to rub that crap off and deposit it into the engine oil....
Using our trusty ol' fine tooth files and brass vise jaw inserts we carefully removed the burrs and proud metal.
And we dropped the cleaned timing chain into a container of break-in oil to soak. Staying overnight in the oil bath and stirring it once in a while should get the chain safely pre-oiled. This chain will get really soaked because it going to set until the rotating assembly gets back from balancing later this week. I didn't soak one of my chains once and I ended up with a galled chain as stiff as a rusty bicycle chain after just a few dyno runs.
Last edited:
LowDeck451
Well-Known Member
I just had this same thing happen with a HFT (casting flash), in my case I just happened to notice a lifter hop when I was turning the cam by hand.
There you go........good eye!
Wow @ the heads, nice work !
Cody started on the intake manifold yesterday while I went on to the cylinder heads. I gotta tell you though, I learned some things about cylinder heads this morning that let me know that I know diddly-squat about cylinder heads. I'm wondering if I can somehow apply the lessons on the next set of heads.......if there is another.
"Hey Cody.......Lest I screw up all your work on these heads........do we have another 346 head I can get some internal measurements from?"
"Yeah Dad......There is another 1973 400 out back that should have 346 heads on it. I'll fire up the forklift and we'll bring it in. We'll use it to build the 400ci engine we've been talking about and pull a 346 for you to destroy. We have a plethora of 906 heads and we can make a pair of those for the 400."
A little snip here and a little snip there..........and voila.......
A measurement here and a measurement there and I figured he'd done a pretty good job already. No sense in accidentally punching a hole in his work or coming across a casting flaw. SO LEAVE THE HEADS ALONE!
"Yeah Dad......There is another 1973 400 out back that should have 346 heads on it. I'll fire up the forklift and we'll bring it in. We'll use it to build the 400ci engine we've been talking about and pull a 346 for you to destroy. We have a plethora of 906 heads and we can make a pair of those for the 400."
A little snip here and a little snip there..........and voila.......
A measurement here and a measurement there and I figured he'd done a pretty good job already. No sense in accidentally punching a hole in his work or coming across a casting flaw. SO LEAVE THE HEADS ALONE!
Interesting to see those cross sections. I had one 452 head that I tweaked just a bit too much once!
I wanted to revisit the engine stand thing and ask your opinion of something I read once, Jim. I cannot remember what team it was......maybe Robert Yates, but I remember whomever it was saying how they don't use the bellhousing style engine stands because they believed the weight of the engine on the stand distorted the engine where some tolerances were concerned. You think there's anything to that?
Supposedly Bob Glidden didn't use engine stands for that reason. Who knows?
I was told by an engine builder that if you put the main caps in the registers on a small block Chevy and put the bolts in loosely, then torqued the heads down, some of the caps would fall. Install and torque the intake manifold and when you're finished all the main caps would be hanging loose. I never tried it.
Do I believe hanging the block by four bolts on the back of the block could distort it.........yes I do.
Do I believe hanging the block by four bolts on the back of the block could distort it.........yes I do.
It's certainly an interesting theory.....and a believable one.
The components of an engine distort, expand do all kinds of **** can't be seem by the naked eye Any time it reaches operating temperatures no matter what it's mounted to, then it goes on back to its normal self once it's shut down. (Thermodynamics)
What am I missing here ?
What am I missing here ?
mygasser
Well-Known Member
it's like if you rebushed all your front suspension and torqued all the bolts while the car's still in the air. when you put it down on it's wheels the bushings are all twisted and under tension. the principle's the same, at least that's how i see it.
neil.
neil.
LocuMob
Fluid Technician
Dang, that's what I did ony car when I rebuilt the front end.
It's held up for years. I'll remember this for the next ones I rebuild. -
