Sir Dodge alot
Active Member
Hello again sir, So higher lift meaning there is going to be more preload on the lifters even with the cam at base circle? I may be asking the incorrect questions here.
Machining work 516 heads port work/bigger valves/hardened seats??
- Thread starter Sir Dodge alot
- Start date
mr gtx
Active Member
preload will be the same no matter what lift.
Sir Dodge alot
Active Member
Thank you very much for another informative write up, I will definitely refer to this page when I'm back home looking at cam cards and comparing by example.
I figure as much that the cams are optimized for popular engines, there was a summit cam that had sold well with most of the purchasers using a 383. I figure if I stuck that boom stick in the 361, it won't work at all or is over cammed.
I think this was the cam that I was looking at in the past, not anymore though.
Duration 288/298
112 LSA 0.444/0.466
CHRYSLER Summit Racing SUM-6400 Summit Racing™ Classic Camshafts | Summit Racing
mr gtx
Active Member
111 LSA is not narrow 104-108 is narrow. smooth idle because 209 is low duration.i would have them put it on a 110 LSA and 106 centerline more bottom end torque.A little more lift would be nice too.
Last edited:
Sir Dodge alot
Active Member
Hello sir, appreciate the clear up, most cam "guides" I have seen say 115 is wide LSA while anything below 112 is narrow, very odd.
Sir Dodge alot
Active Member
I know most of you gentleman already know what the cam cards will give you in terms of performance.
This video by Richard Holdener, has done a few Dyno runs with cams that only changed the LSA while keeping the cam specs the same, i thought it was a good video to help me visualize what the difference in LSA changes do.
But I realize looking at the LSA only is just a small piece of the cake, but it helped me in my journey understanding what spec does what.
Pictures below comparing the change in LSA's on a Dyno graph.
Yes, I have committed the sacrilege of posting LS Dyno engines on holy grounds of where Chryslers reside.
This video by Richard Holdener, has done a few Dyno runs with cams that only changed the LSA while keeping the cam specs the same, i thought it was a good video to help me visualize what the difference in LSA changes do.
But I realize looking at the LSA only is just a small piece of the cake, but it helped me in my journey understanding what spec does what.
Pictures below comparing the change in LSA's on a Dyno graph.
Yes, I have committed the sacrilege of posting LS Dyno engines on holy grounds of where Chryslers reside.
Last edited:
Yes, a smooth idle is possible with a 110LCA and 210@.050" duration in a 350CID motor. That's what was in my 305 and also in the 355 that replaced it. What I DID discover with the 305 was that in gear, with the a/c running, at abt 550rpm, manifold vac was at 10.5" Hg, which was .5"Hg above where the first stage of the two-stage power valve would open. In "N", the vac was higher, as would be expected in a no-load situation.
In respect to the two-stage Holley power valve is that when the first stage opened, it did not enrich the mixture very much. Main-stage opening was at 5.5" Hg, where a normal Holley power valve opens. AFR dropped significantly.
Typically, idle smoothness is related to duration and cyl-to-cyl filling variations being very low. With a fuel system that atomizes the fuel better and an ign system that zaps each cylinder's mixture completely.
CBODY67
Your indiscretion is acknowledged, in the name of "data".
ONE thing is to not "over-think" things. Notice how the red line is above the other lines, or even over-lays them in a few places. That is the narrowest LCA in action. 107* in this case. But past a point, they are all so very close it is of little consequence.
Back in high school, I documented the power absorption of a Chrysler Corp rwd TF powertrain, crankshaft flange to tire patch (with bias ply tires), to be right at 16% of total engine power. So if you decrease the engine horsepower in the dyno charts by a factor of .85, THAT is the power felt to move the car forward. By observation, it can take a "very calibrated" internal accelerometer to feel 10 horsepower, much less 8.5 . The ET clocks at the drag strip can measure it, but then driver execution of the launch and other things can compensate for that amount, too. To me, that is the reality of the situation.
In modern times, it seems that everybody is "a slave" to dyno chart numbers at peak rpm. How many people really drive at that rpm on the streets and highways, legally and safely? Gotta have those NUMBERS! Bragging rights? Yet a lesser engine might spank it on normal street maneuvers! How can that be possible? "The numbers" say otherwise. Yet the real issue is how much time it took the car to get through the total rpm range to that peak power level that wins races. Better lower and mid-range torque do that, IF the chassis can handle it AND the driver knows how to best make use of it.
"Over-thinking" can be good as one considers ALL of the options over a period of time. Then, IF and WHEN a decision is made, it will be made confidently. "Second-guessing", by comparison, can lead to procrastination, anxiety, and other things which hinder progress.
Enjoy!
CBODY67
ONE thing is to not "over-think" things. Notice how the red line is above the other lines, or even over-lays them in a few places. That is the narrowest LCA in action. 107* in this case. But past a point, they are all so very close it is of little consequence.
Back in high school, I documented the power absorption of a Chrysler Corp rwd TF powertrain, crankshaft flange to tire patch (with bias ply tires), to be right at 16% of total engine power. So if you decrease the engine horsepower in the dyno charts by a factor of .85, THAT is the power felt to move the car forward. By observation, it can take a "very calibrated" internal accelerometer to feel 10 horsepower, much less 8.5 . The ET clocks at the drag strip can measure it, but then driver execution of the launch and other things can compensate for that amount, too. To me, that is the reality of the situation.
In modern times, it seems that everybody is "a slave" to dyno chart numbers at peak rpm. How many people really drive at that rpm on the streets and highways, legally and safely? Gotta have those NUMBERS! Bragging rights? Yet a lesser engine might spank it on normal street maneuvers! How can that be possible? "The numbers" say otherwise. Yet the real issue is how much time it took the car to get through the total rpm range to that peak power level that wins races. Better lower and mid-range torque do that, IF the chassis can handle it AND the driver knows how to best make use of it.
"Over-thinking" can be good as one considers ALL of the options over a period of time. Then, IF and WHEN a decision is made, it will be made confidently. "Second-guessing", by comparison, can lead to procrastination, anxiety, and other things which hinder progress.
Enjoy!
CBODY67
Sir Dodge alot
Active Member
Hello again sir, The procrastination really does ring true, I don't understand all of the cam card Lingo, and the acosiated cam timing mechanics, pretty much slows my project to a halt most of the time while I attempt to wrack my brain on how and what certain terminology are correct and wrong, sort of like measuring the crank rod journals.
In turn as you say over thinking things.
I'll get there someday though.
With a reminder to not over think things.
Last edited:
Sir Dodge alot
Active Member
Hello sir, I had a question regarding your Newport? With the 440, what is the compression ratio? I figured while I'm in here with the engine blown apart (hopefully won't "blow up" once it's all back together, knock on wood) I'd deck the block 10 thousands and 10 thousands of of the head/intake to boost the compression some, but not into 9.5:1 territory.
(Changes to Valve train geometry will come into play I'd assume also or get some rocker shaft shims... Or is this a can of worms I should not get into right at this moment?)
Thank you.
Last edited:
mr gtx
Active Member
9.6 compression. won't need shims if anything longer push rods. lifters have 180-200 thousands of travel. so anyway from at least 60 to 120 thousands preload is good. sounds like you're not going to bore it out? you can mill the block or head more unless you're using a stock shim head gasket. you do know at least one of your connecting rod journals are under sized ?
Last edited:
In machining the block surfaces, you don't go in and just knock off a certain amount of metal, you FIRST see how "square" the block is. All based on the crankshaft area. THEN you check for how accurate the cylinder deck surfaces are, especially front to back. Presuming the factory block casting is "perfect" in all respects is not completely accurate.
Once the crankshaft saddles are line honed, then you move upward to the cylinder decks. Getting them square as to block blueprint specs. Once the decks are trued-up (according to the crankshaft being in the desired place), then the cylinders are next . . . to bore and then hone, hopefully with deck plates installed.
It would appear that if much of the block surface is removed in the decking process, that CR would increase, which it can. BUT it is really just getting the deck height to what the specs call for. Which can mean that the as-produced CR is less than specified. So the decking operation just "makes things right".
Getting the deck surface of cylinder heads "right" is normally a part of a good valve job. Some shave off even more for an increase in CR. A "serious" method of doing this is "angle milling", where rather than the cyl head being set-up "flat" on the lathe, the levelers are changed to allow for an angle cut instead. Taking more metal off of one side rather than evenly. When a Chrysler 906 head is angle milled, it suddenly starts to look surprisingly like a small block Chevy head! I saw that myself at my late machine shop operative's shop one weekend.
When cyl heads are milled past a certain amount, then the intake manifold side must be milled an appropriate mount to maintain all factory angles, for intake manifold sealing purposes.
Are all of these machine shop operations necessary for a good-running motor? No, but when the level of use gets to where the absolute most power and efficiency are needed to win races or enhance longevity, "yes".
In doing a rebuild, during the tear-down, any misalignment of the crankshaft will usually be evident in the wear of the crankshaft bearings. My machine shop guy even commented about an engine he got in which had unusual wear on the upper bearing of #1 main bearing, compared to the others. Excessive drive belt tightening was his diagnosis, for example. If all of the bearings are worn evenly, the line hone dimension can be suspected to be good.
Moving upward, "Just Mopar Joe" commented about block "twists", where the decks are not square to the crank or each other. That would be obvious in the decking process, but not in other situations, I suspect. Might affect intake manifold sealing, though.
So, paying attention to wear points in the engine during disassembly is important. Bearing wear patterns, gasket compression amounts, etc. The "good thing" is that, as the engine has been together for so long, the cast iron mix in the block has completed curing long ago, any machining to the block will "stay put" in the future. Which can make the time and expense a good investment in future longevity of the block. Then with modern items like "MM" piston rings (and pistons to take them), OEM-level wear parts, and better motor oils, the older engines can have a valid service life for many more 100,000s of miles. If I can get an OEM '77 Chevy 305 to pass 500K miles (with a roller timing chain, of course, added at 92K miles), then a Chrysler Corp engine rebuild should go twice that, I suspect. Daily-driving use rather than racing use.
As my Camaro neared 200K miles, I joked to myself that if I could get a stock Chevy motor to last that long, a Chrysler motor should be "forever". In the USA, people usually traded a car off well before that, so nobody really KNEW how long a production Chevy engine might last with good maintenance. What finally made it necessary to pull the engine was the leaking block core plugs. Oil consumption had increased to 1 qt per 2500 miles. From .5qt per 4000 miles at 10K miles. Originally with GTX 20W-50 to Rotella T6 5W-40 in later years. YOUR experiences might vary!
Enjoy!
CBODY67
Once the crankshaft saddles are line honed, then you move upward to the cylinder decks. Getting them square as to block blueprint specs. Once the decks are trued-up (according to the crankshaft being in the desired place), then the cylinders are next . . . to bore and then hone, hopefully with deck plates installed.
It would appear that if much of the block surface is removed in the decking process, that CR would increase, which it can. BUT it is really just getting the deck height to what the specs call for. Which can mean that the as-produced CR is less than specified. So the decking operation just "makes things right".
Getting the deck surface of cylinder heads "right" is normally a part of a good valve job. Some shave off even more for an increase in CR. A "serious" method of doing this is "angle milling", where rather than the cyl head being set-up "flat" on the lathe, the levelers are changed to allow for an angle cut instead. Taking more metal off of one side rather than evenly. When a Chrysler 906 head is angle milled, it suddenly starts to look surprisingly like a small block Chevy head! I saw that myself at my late machine shop operative's shop one weekend.
When cyl heads are milled past a certain amount, then the intake manifold side must be milled an appropriate mount to maintain all factory angles, for intake manifold sealing purposes.
Are all of these machine shop operations necessary for a good-running motor? No, but when the level of use gets to where the absolute most power and efficiency are needed to win races or enhance longevity, "yes".
In doing a rebuild, during the tear-down, any misalignment of the crankshaft will usually be evident in the wear of the crankshaft bearings. My machine shop guy even commented about an engine he got in which had unusual wear on the upper bearing of #1 main bearing, compared to the others. Excessive drive belt tightening was his diagnosis, for example. If all of the bearings are worn evenly, the line hone dimension can be suspected to be good.
Moving upward, "Just Mopar Joe" commented about block "twists", where the decks are not square to the crank or each other. That would be obvious in the decking process, but not in other situations, I suspect. Might affect intake manifold sealing, though.
So, paying attention to wear points in the engine during disassembly is important. Bearing wear patterns, gasket compression amounts, etc. The "good thing" is that, as the engine has been together for so long, the cast iron mix in the block has completed curing long ago, any machining to the block will "stay put" in the future. Which can make the time and expense a good investment in future longevity of the block. Then with modern items like "MM" piston rings (and pistons to take them), OEM-level wear parts, and better motor oils, the older engines can have a valid service life for many more 100,000s of miles. If I can get an OEM '77 Chevy 305 to pass 500K miles (with a roller timing chain, of course, added at 92K miles), then a Chrysler Corp engine rebuild should go twice that, I suspect. Daily-driving use rather than racing use.
As my Camaro neared 200K miles, I joked to myself that if I could get a stock Chevy motor to last that long, a Chrysler motor should be "forever". In the USA, people usually traded a car off well before that, so nobody really KNEW how long a production Chevy engine might last with good maintenance. What finally made it necessary to pull the engine was the leaking block core plugs. Oil consumption had increased to 1 qt per 2500 miles. From .5qt per 4000 miles at 10K miles. Originally with GTX 20W-50 to Rotella T6 5W-40 in later years. YOUR experiences might vary!
Enjoy!
CBODY67
Last edited:
^This^
Even if it was "perfect" at the factory, cast iron moves around. Heating cycles and age. And they were never "perfect". They had some fairly close tolerances that they managed to hit, but it was still mass production.
It used to be that the engine blocks would sit for some time after casting and before machining so they were a bit more stable for the long term.
I knew engine builders that preferred using blocks with 100k plus miles on them because they are considered "seasoned" and aren't going to change after machining.
Sir Dodge alot
Active Member
Hello sir,
Is there some sort of method to calculate how much gets milled off in relation of selecting the correct pushrod length?
Yes as much as I'd like to not bore out the cylinders, it might become a reality though.
Yes sir, 10 thou undersized journals, weaker yes. But I have no doubt the stresses I'm putting on the engine is not high as a daily driver engine.
I've heard steel shim gasket's like the factory copper shim can no longer be used if you mill the heads/deck because the shims have worn a groove into the head/deck surfaces.
And vice versa.
Thank you.
Last edited:
RemCharger
Well-Known Member
The correct method would be put it together and measure what you actually have.
You can use a steel shim again if you like, no problem.
Sir Dodge alot
Active Member
Hello sir,
Ok, so as Big_John has also said, in the meantime I'm doing the usual routine of a freshen up.
My hypothesis is this: everything talked about in this thread, all the attention to detail, while correct, probably wouldn't add up to 20hp on an oem 361.
You might feel that. Line up 6 361 cars and it'd feel the strongest, sure. And you'll spend $5k at least for that 20hp.
The reality is from a cost perspective, spending $1 on 516's or a 361 doesn't make sense worse, the 361 bore is so small aftermarket heads don't make sense either. My advice would be to find someone selling reworked OEM heads. Smart people have told me the better flow of a 906 in the mid range is more valuable than a little bit of compression from 516's.
I really like the passion in this thread!
You might feel that. Line up 6 361 cars and it'd feel the strongest, sure. And you'll spend $5k at least for that 20hp.
The reality is from a cost perspective, spending $1 on 516's or a 361 doesn't make sense worse, the 361 bore is so small aftermarket heads don't make sense either. My advice would be to find someone selling reworked OEM heads. Smart people have told me the better flow of a 906 in the mid range is more valuable than a little bit of compression from 516's.
I really like the passion in this thread!
Sir Dodge alot
Active Member
Hello sir,
I have considered the use of 906's, with it's "modern" port designs like the 915's. Enticing indeed, there's a junkyard local to me, they have Dodges/Chryslers/Desotos/plymouths, the owner I believe he grabs the usable parts (like the heads) and has them for sale. But that was a few months back, so the heads are probably sold.
As you say spending a dime even on a 361 with 516's were probably a waste.
But I have an innate desire to use otherwise throwaway heads/engines to make something work, (more on this later)
Going off tangent here, ever watched a YT channel called Uncle Tony's garage?, he built a 318 with mostly factory components with some being worn out parts. And the car runs 10's?? Or 12's?? Was it?
Anywho, that 318 was the most cool thing I watched, instead of firing the parts cannon to get new heads/pistons/crank/roller setups.
Most of the inspiration of that 318 is kind of what I saw in the 361, and arrived to this moment now, which is not much, sure the 361 isn't going to be the new "hot" build, but it will get me from point A to B reliably.
I'm rambling as usual.
However, I will look around locally if there are 906's somewhere, if not, not a big deal, I'll work with what I've got (mostly)
Thank you for proposing the idea of the reworked heads. I will see if there are any more locally.
He runs his stuff on an 1/8th mile drag strip. Multiply those times by 1.56 to get 1/4 times. 10 sec ET in an 1/8th mile equals ~15.6. That works out to as SLOW AF.
That said, I like some of the stuff he does. Basically, backyard builds with minimal tools etc. In some ways, that's good as it shows that you can go have some fun without spending a lot of money.
In other ways, it's bad because he is skipping over better ways to do things. For example, a spring hone works for honing an engine that you just want to knock the glaze off the cylinders. (Actually a ball hone is better), but a spring hone isn't going to straighten the cylinder walls.
It's level of execution, plain and simple. IMHO, he isn't the example of doing it the right way.
But if you are looking for performance, I'd suggest replacing that 361 with something bigger. No replacement for displacement.
wyrmrider
Member
Hi I've read all the posts so comments are not on a specific post
We raced 361 in stock class back in the day
(IDK but would LS valves work)
and put in a radius seat and do not back cut the exhausts multi angle valve job and blend the bowls but keep it simple, just clean it up
On the intakes you can go slightly larger If it was me I'd get some 2.02 or similar intake and cut them down to a more resonable size
actually if it was me in a heavy car with tall gears I'd convert INTAKES to 30 degree valve angles sitting the new seat on the old top cut then multi angle valve job, no radius seat as you need the angles to shear the fuel, no separation of fuel and air do the math and see what a larger curtain area you get with the 30 degree seat
I 100% agree that the 256 degree Howard is the way to go (or 256 Mike Jones motorhome cam) I would get the cam from Mike and get the professional advice well worth the premium
for example let him pick the exhaust lobe and the seat timing the LSA is just a result Iended up with about 10 degrees more exhaust and 112LCA But your mileage WILL different and I had ported 915 heads with MOTORHOME Valves heavy Inconel exhausts
you are going to end up with around .305 lobe lift or around 450 valve lift so porting for more makes no sense
The lighter valve weight makes a big difference. You can set up for modern beehive springs and use Viton retainers
It is going to be tough to get quench with available 361 pistons cutting the heads does not help
AND CUTTING open chamber heads does not work you have to weld the chambers or get quench dome pistons (I've done custom for matching number 383s some with strokers
Enough
If this was a matching number restore then do the 361 otherwise find a 400 block and build that and if you need pistons and the crank then do a stroker
that heavy car will love you you will get over 60 more ft lbs of torque and you cannot get it any other way
It will not like a larger cam been there done that
cheers
We raced 361 in stock class back in the day
(IDK but would LS valves work)
and put in a radius seat and do not back cut the exhausts multi angle valve job and blend the bowls but keep it simple, just clean it up
On the intakes you can go slightly larger If it was me I'd get some 2.02 or similar intake and cut them down to a more resonable size
actually if it was me in a heavy car with tall gears I'd convert INTAKES to 30 degree valve angles sitting the new seat on the old top cut then multi angle valve job, no radius seat as you need the angles to shear the fuel, no separation of fuel and air do the math and see what a larger curtain area you get with the 30 degree seat
I 100% agree that the 256 degree Howard is the way to go (or 256 Mike Jones motorhome cam) I would get the cam from Mike and get the professional advice well worth the premium
for example let him pick the exhaust lobe and the seat timing the LSA is just a result Iended up with about 10 degrees more exhaust and 112LCA But your mileage WILL different and I had ported 915 heads with MOTORHOME Valves heavy Inconel exhausts
you are going to end up with around .305 lobe lift or around 450 valve lift so porting for more makes no sense
The lighter valve weight makes a big difference. You can set up for modern beehive springs and use Viton retainers
It is going to be tough to get quench with available 361 pistons cutting the heads does not help
AND CUTTING open chamber heads does not work you have to weld the chambers or get quench dome pistons (I've done custom for matching number 383s some with strokers
Enough
If this was a matching number restore then do the 361 otherwise find a 400 block and build that and if you need pistons and the crank then do a stroker
that heavy car will love you you will get over 60 more ft lbs of torque and you cannot get it any other way
It will not like a larger cam been there done that
cheers
Similar threads
