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Re: Another street/strip 440 rebuild [Re: mopar67440] #1638720
06/27/14 06:05 PM
06/27/14 06:05 PM
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dogdays Offline
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That's what I think.
R.

Re: Another street/strip 440 rebuild [Re: dogdays] #1638721
06/27/14 10:26 PM
06/27/14 10:26 PM
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GTX MATT Offline
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IMO with .040 quench and 10:1 or less you'd be ok. You could get away with a 509 in a 9.5:1 engine with no quench, so I don't see why half a point more with quench wouldn't work.


Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street
Re: Another street/strip 440 rebuild [Re: mopar67440] #1638722
06/28/14 12:01 AM
06/28/14 12:01 AM
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Quote:


I'm guessing what your driving at is, I should have cc'd the heads and equalized them, then measured the piston step to calculate exact compression ratio & quench.




No, what I believe he is getting at is if you want to actually get some benefit of the reverse dome with proper quench, you need to know exactly how far above the deck the piston comes, know what head gasket you will be using, and then measure and work each combustion chamber "flat area" to the same and correct depth to acquire the desired piston to head quench clearance.

Re: Another street/strip 440 rebuild [Re: BSB67] #1638723
06/29/14 08:44 PM
06/29/14 08:44 PM
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Are the 236s the same as the 146s, just thinner ring pack for the 146s. Cant remember. If so, i have some real world experience w them on 3 different combos.

I will say, in my experience, most of the compression numbers vs safe pump gas use, being tossed around are very conservative. Yrmv.

Last edited by Von; 06/29/14 08:47 PM.

72 RR, Pump gas 440, 452s, 3800 lbs, Corked, ET Radials,. 11.33@117.72. Same car, bone stock 346s, 9.5 comp, baby solid. 12.24@110.
Re: Another street/strip 440 rebuild [Re: Von] #1638724
07/08/14 04:31 PM
07/08/14 04:31 PM
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mopar67440 Offline OP
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Thank you everyone who chimed in. Gave me a lot to think about and made me realize I may have made a few mistakes and false assumptions when bolting the heads on, so I've decided to take a step back and verify some of the critical measurements before going any further with the rebuild.

One mistake was in a suggestion from a friend...who btw is a great mechanic & he meant well, but he's not much on the engineering side. He suggested the Fel Pro 0.037" composite gasket to reduce compression to run on pumped gas. I now realize this is most likely a bad choice at the sacrifice of quench, not knowing for sure if the heads were surfaced, and whether the CC's are equal across all chambers.

The plan is to remove the heads and cc all 8 chambers. A question I have is... once I know this, how close to each other should they be, and what is the best approach to equalizing them?

The second step is to measure the actual quench area across all 8 pistons (both ends and center of piston) to head using the rosin core solder method I've read a lot about. I believe once I know this, I can select the appropriate compressed head gasket thickness.
A few questions;
1) should I make the measurement without gaskets and the heads completely or lightly torqued?
2)Once I have this measurement, where in the 0.035"-0.040" quench area should I strive for...the 0.035" minimum or stay on the safer side of 0.040"? For instance, if I measure 0.018" quench without a head gasket, by using the compressed steel 0.020" gasket, I would be at 0.038" Considering the KB236 pistons, Eagle rods, average rod bearing clearance, and a rev limit of 6000-6500, this would be a good choice.

Re: Another street/strip 440 rebuild [Re: mopar67440] #1638725
07/08/14 06:01 PM
07/08/14 06:01 PM
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Quote:

The 906's were never milled and I never cc'd each cylinder to check consistency. Going by production numbers, I'm assuming the heads are somewhere in the 88-90cc range, so based on the KB piston specs of 1.8cc piston step & stock stroke, compression is 10.5:1 @85cc's, 10.0:1 @90'cc. with a 0.040" gasket compression, or 10.96:1 @85cc to 10.45:1 @90cc with 0.020" compression.

I'm guessing what your driving at is, I should have cc'd the heads and equalized them, then measured the piston step to calculate exact compression ratio & quench.




WHAT production numbers ??? I've never seen any and YES you should have done all that , especially with those heads and pistons and crank and rods unless you paid to have the crank rods and pistons checked/size matched.

I had a 383 screwed together on it's at least second rebuild , friend I'm helping is on a LOW fixed budget/retired , the piston to deck heights are all over the place, he doesn't have to worry about quench , it has none ...

Re: Another street/strip 440 rebuild [Re: mopar67440] #1638726
07/08/14 06:14 PM
07/08/14 06:14 PM
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Quote:

Thank you everyone who chimed in. Gave me a lot to think about and made me realize I may have made a few mistakes and false assumptions when bolting the heads on, so I've decided to take a step back and verify some of the critical measurements before going any further with the rebuild.

One mistake was in a suggestion from a friend...who btw is a great mechanic & he meant well, but he's not much on the engineering side. He suggested the Fel Pro 0.037" composite gasket to reduce compression to run on pumped gas. I now realize this is most likely a bad choice at the sacrifice of quench, not knowing for sure if the heads were surfaced, and whether the CC's are equal across all chambers.

The plan is to remove the heads and cc all 8 chambers. A question I have is... once I know this, how close to each other should they be, and what is the best approach to equalizing them?

The second step is to measure the actual quench area across all 8 pistons (both ends and center of piston) to head using the rosin core solder method I've read a lot about. I believe once I know this, I can select the appropriate compressed head gasket thickness.
A few questions;
1) should I make the measurement without gaskets and the heads completely or lightly torqued?
2)Once I have this measurement, where in the 0.035"-0.040" quench area should I strive for...the 0.035" minimum or stay on the safer side of 0.040"? For instance, if I measure 0.018" quench without a head gasket, by using the compressed steel 0.020" gasket, I would be at 0.038" Considering the KB236 pistons, Eagle rods, average rod bearing clearance, and a rev limit of 6000-6500, this would be a good choice.




I wouldn't worry too much about making the chambers equal unless they are really far apart , the IMPORTANT measurement is the distance from the head deck to the cast area that is the open part of the chamber , they are NEVER the same or even flat in any direction ... at least not that I have ever measured on any of the heads I have machined.

As far as the .037 Felpro composite , no such animal , they are .040ish and you do not have a bunch of different thicknesses to choose from. Steel shim head gaskets run .021 for the most common gasket , Cometic has one that is .027 $$$$

You need to know how far above the block deck the step of the piston is sitting , no gasket.

Was the block SQUARED during any of the rebuild processes ? If not that will add to the fun. Don't be surprised to see the steps not all at the same height , even if the block was squared.


Shoot for . 040 , and hope for between .035 and no more than .045, if the heads were never cut you'll need a step that is roughly .0080 above the deck ... assuming a .021 head gasket and .100 chamber depth.

Measure the head bolt boss under the exh ports , uncut heads will be basically 1.000 , if the heads have not been surfaced they should be so you know they are flat, you can take material off the head decks to get quench , but that is going to raise your compression ratio. don't be surprised to get chamber volumes of 90-92 cc.

also make note that KB , and most aftermarket piston makers for mopar think everyone has blocks that have been decked about .020 when calculating compression ratios and picking a compression height.

Re: Another street/strip 440 rebuild [Re: JohnRR] #1638727
07/09/14 03:57 PM
07/09/14 03:57 PM
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Thanks John,

I'll be pulling the heads Friday and hope to have most of the measurements complete by Monday.

My mistake...it was a .040" Fel-Pro gasket I used, however I did find the following compressed head gaskets for a 4.380" bore between Summit, Mancini, Jegs, and 440Source;

Mopar Performance
P4286754 - .020"
P5155237 - .025"
P4349559 - .040"
Cometic
C5461-027 - .027"
C5461-040 - .040"

Many selections above .040" between Mopar, Fel-Pro and Cometic if I need to go there.

Re: Another street/strip 440 rebuild [Re: mopar67440] #1638728
07/09/14 11:58 PM
07/09/14 11:58 PM
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I've found that .010" off the deck and .015"-.020" off the heads, with a .020" head gasket will yield the ideal quench with those KB quench dome pistons.

Re: Another street/strip 440 rebuild [Re: lewtot184] #1638729
07/10/14 12:58 PM
07/10/14 12:58 PM
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Thanks for the suggestion. I would hate to have to disassemble the bottom end to mill the deck. I'm still not entirely sure if the heads where ever milled. I'm assuming they have at some point.

I need to make all the critical measurements first, then I can make an informed decision on the course of action that get's me close to ideal without breaking the bank.

Re: Another street/strip 440 rebuild [Re: mopar67440] #1638730
07/10/14 08:44 PM
07/10/14 08:44 PM
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Quote:

Thanks for the suggestion. I would hate to have to disassemble the bottom end to mill the deck. I'm still not entirely sure if the heads where ever milled. I'm assuming they have at some point.

I need to make all the critical measurements first, then I can make an informed decision on the course of action that get's me close to ideal without breaking the bank.


the block doesn't have to be milled to get the correct quench but most folks have the block squared up. everything can be done on the head. just use a depth mic to measure the open area in the head. also use some .011" or .012" to square the piston up in the bore when measuring the quench dome's positive deck. it's fairly easy but takes about an hour to do all eight.

Re: Another street/strip 440 rebuild [Re: lewtot184] #1638731
07/11/14 01:56 AM
07/11/14 01:56 AM
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If it's already together, I would leave it alone. It's either going to ping or it's not.
If it does, then decide what to do.
If it were me I would just put some edelbrocks on it.

Re: Another street/strip 440 rebuild [Re: viperblue72] #1638732
07/11/14 02:06 PM
07/11/14 02:06 PM
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There are just so many variables at this point to consider that guessing will most likely result in disappointing performance and a huge waste of time, so in my mind the right thing to do as has been emphasized over and over again here is, take the extra time up front too accurately measure all areas of concern and address each of the issues as best I can.
- piston quench to deck
- piston flat to deck
- piston quench to head w/ no gasket - both ends & middle of piston
- CC cylinder heads

Re: Another street/strip 440 rebuild [Re: mopar67440] #1638733
07/12/14 01:41 AM
07/12/14 01:41 AM
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You are correct and many of us learned the same way you are.
There are many variables, but you know approximately what your compression ratio will be.
The performance won't be disappointing with 10.5 compression or roughly that.
Your choice of parts are not that bad. I would honestly rather have a little too much compression than not enough. That's when performance will be disappointing.
Plus you will have an excuse to pump some good heads on it if it doesn't run on pump fuel.
It would run fine on pump fuel with aluminum heads.

Last edited by viperblue72; 07/12/14 01:47 AM.
Re: Another street/strip 440 rebuild [Re: viperblue72] #1638734
07/12/14 02:06 AM
07/12/14 02:06 AM
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Also if you use the fel pro or any gasket for that matter, make sure the gasket doesn't hang into the chamfer of the bore. 440's have a huge chamfer and require a bigger bore gasket.

Re: Another street/strip 440 rebuild [Re: viperblue72] #1638735
07/13/14 12:03 AM
07/13/14 12:03 AM
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Different heads are not a financial option at this point, so I'm going to make the best of the 906 heads I have.

So far all the research I've done tells me it's a balancing act between quech and compression. If I can acheive the .040"-.045" quench with compression around 9:5-10:1. Then between octane, air/fuel, timing, fresh air intake and a cool engine temp I should be able to dial it in to perform strong and reliably.

I'm actually loving the science and engineering behind it all. I think it will all be well worth the effort when I turn the key, break it in, fine tune it, and get to finally enjoy the fruits of my labor.
It's only been 12 years since it last ran... and I now know so much more about Mopar....thanks to this forum and all the info on the internet...it really got me thinking

Love it love it love it!!!

Re: Another street/strip 440 rebuild [Re: mopar67440] #1638736
07/15/14 06:42 AM
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Another idea that would help a little would be to polish the combustion chambers.

Re: Another street/strip 440 rebuild [Re: viperblue72] #1638737
07/15/14 02:45 PM
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ok...so now I have some real numbers to work with. The measurements were taken many times over until I had a fairly confident process with repeatability.

Quench clearance w/no head gasket = 0.045"
- Heads were torqued to approx. 35 lbs
- Used rosin core 60/40 solder over length of step
- Crushed 3 times at TDC
- Both ends & middle of solder measured & averaged
- All cylinder were within 0.005" of each other
- Very little piston rock was noticed across the solder

Piston step head to deck = 0.039"
- Piston brought to TDC with dial indicator
- Measurements made with straight edge & feeler gauge @center of piston

Flat of piston (valve reliefs) to deck = -0.034" below deck
- Piston brought to TDC with dial indicator
- Measurement made with straight edge & feeler gauge @center of piston

Head CC's
- All were 82-83 CC's
- One was at 80 CC
- Double checked all measurements
- Allowed water to sit in chamber for 15 minutes w/ no valve leaks observed.

Head bolt bosses at the exhaust side were also checked as suggested, and were at 0.975" indicating heads were most likely milled.

Looking at the numbers, with a 0.020" head gasket the quench area will end up at 0.065", which is far from ideal.

Also looks like compression is somewhere at 10.5:1.

Any thoughts?

Re: Another street/strip 440 rebuild [Re: mopar67440] #1638738
07/15/14 04:03 PM
07/15/14 04:03 PM
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Quote:

ok...so now I have some real numbers to work with. The measurements were taken many times over until I had a fairly confident process with repeatability.

Quench clearance w/no head gasket = 0.045"
- Heads were torqued to approx. 35 lbs
- Used rosin core 60/40 solder over length of step
- Crushed 3 times at TDC
- Both ends & middle of solder measured & averaged
- All cylinder were within 0.005" of each other
- Very little piston rock was noticed across the solder

Piston step head to deck = 0.039"
- Piston brought to TDC with dial indicator
- Measurements made with straight edge & feeler gauge @center of piston

Flat of piston (valve reliefs) to deck = -0.034" below deck
- Piston brought to TDC with dial indicator
- Measurement made with straight edge & feeler gauge @center of piston

Head CC's
- All were 82-83 CC's
- One was at 80 CC
- Double checked all measurements
- Allowed water to sit in chamber for 15 minutes w/ no valve leaks observed.

Head bolt bosses at the exhaust side were also checked as suggested, and were at 0.975" indicating heads were most likely milled.

Looking at the numbers, with a 0.020" head gasket the quench area will end up at 0.065", which is far from ideal.

Also looks like compression is somewhere at 10.5:1.

Any thoughts?




Yes at .065 you basically have no quench , it is what it is unless you want to cut the heads .020 , I'd cut .025 because of your .005 variance , but then your compression is going to be higher.

Drop your head gasket on the head and see how much overhang of the chamber there is inside the gasket, scribe the gasket onto the head, drop 1\4" dowels in the head to hold the gasket, and scribe the chamber size and grind all the overhang away and polish the chambers and see how much you raised the chamber CC.

Re: Another street/strip 440 rebuild [Re: JohnRR] #1638739
07/15/14 04:27 PM
07/15/14 04:27 PM
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mopar67440 Offline OP
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That's what I figured...no quench & I can hear the pinging already.
So if I mill the heads .015-.020, compression goes up too...and there's real no benefit?
I thought I saw this info somewhere and can't put my finger on it, but what is 0.010" equal to in CC's?

btw...I was thinking about one other measurement I made that I did not publish here. I put a straight edge across the head, and measured 0.073" with a feeler gauge to the flat of the chamber. If I take that value, subtract the quench dome of 0.039", that's 0.034" (0.011" less than the solder test). I wonder if the solder didn't crush down all the way. That would place quench at 0.054"...still 0.014" less than ideal, but better.

Is grinding out the head overhang a typical approach to increasing the CC's? I assume leave the quench area alone.

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