|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638740
07/15/14 05:20 PM
07/15/14 05:20 PM
|
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
|
Quote:
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.
The solder was obviously causing the piston to rock while crushing, I wouldn't use that to determine a value, doing it with the straight edge and feeler blades, and math is, more accurate.
For BB open chamber head, .005 for every CC , .015 3cc, .020 4cc, .025 5cc
No there is a benefit , but you have iron heads and possibly not high enough octane because of the iron heads not succking out more of the combustion heat, faster, like an alum head does. Quench/squish is not the magic bullet, but it helps.
i'd want .045 MAX  , anymore and you may as well leave it at .065.
To increase CC, think about it, the chamber needs to be BIGGER ... yes leave the quench area alone except to maybe smooth it, but try not to make it deeper , the smoother/shiner it is the less chance for hotspots that will help cause detonation.
|
|
|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638742
07/21/14 10:31 AM
07/21/14 10:31 AM
|
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
|
Quote:
Thanks John for the cc info. and all your guidance.
So if I use the feeler gauge numbers it looks achievable...
.073 chamber depth
less .039 dome height
less .010 off the heads
add .020 head gasket
.043 total quench
With .010 off the heads, that will reduce CC's to approx 80-81. The piston is .034 in the hole which equates to approx 6.8 cc. Valve reliefs are at 1.8 cc based on KB236 spec. So with a total CC at approx 88.6, what would the SCR be...around 10.0:1?
I'll take your suggestion and polish the chambers the best I can shy of removing valves to accomplish any major ginding.
Not sure if it's worth anything, but while the heads were off, I selected 8 spark plugs that were indexed correctly.
I think if you can get .043 quench you will have a good chance. The pfirst build I helped out on had roughly the same quench, same pistons and 73/75 cc 906 heads, the guy had no issue running on the street with 93 oct, but this was back before Ethanol, but I think the gas had MBTE in it ??
The odd part was that this build mimic'd his friends build, I was just involved with collecting parts and doing chamber mods on the heads, and his friends engine with 9.5 compression and .065 quench woulkd not run on anything less than 93 without pinging, they both ignore KB's recommendation of 34 max advance ?
If it were me I would take the .010 out of the open part of the chamber that way you end up with perfectly matched chamber depths and add CC to the chambers.
What part of Ma. are you in ?
|
|
|
Re: Another street/strip 440 rebuild
[Re: JohnRR]
#1638744
07/21/14 11:41 AM
07/21/14 11:41 AM
|
Joined: Oct 2003
Posts: 3,698
NE Oklahoma
Von
master
|
master
Joined: Oct 2003
Posts: 3,698
NE Oklahoma
|
Using the Diamond compression calc, I come up with 10.47... http://www.diamondracing.net/tools/
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: mopar67440]
#1638745
07/21/14 01:34 PM
07/21/14 01:34 PM
|
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
|
Quote:
Not sure what you mean...
"If it were me I would take the .010 out of the open part of the chamber that way you end up with perfectly matched chamber depths and add CC to the chambers."
Are you referring to grinding back the open part of the chambers to the edge of the head gasket?
I am in Marlborough, MA btw.
I screwed up, I was thinking you needed to make the open part of the chamber deeper, not shallower. What I have done in the past wouldn't help you.
But yes scribe the head gasket opening onto the head and grind it back to that to gain chamber volume.
I like the idea of using the thinner gasket that way if you have to cut the heads again you can just use the thicker gasket and still be safe.
|
|
|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638747
07/21/14 01:48 PM
07/21/14 01:48 PM
|
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
|
Quote:
Where do you think SCR is without this extra work...10.5? With the quench at .043 & timing backed off to around 34 degrees, think it's really necessary? Grinding all 8 chambers back to the 4.320 mark is going to be a lot of work.
It's good practicefor you and your penance for using poor cylinder head choice. 
I had 50 hours in the last set of open chambers head setting up for quench I used ... good thing I do it for free ...
|
|
|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638748
07/21/14 02:34 PM
07/21/14 02:34 PM
|
Joined: Oct 2003
Posts: 3,698
NE Oklahoma
Von
master
|
master
Joined: Oct 2003
Posts: 3,698
NE Oklahoma
|
Quote:
think it's really necessary?
As I mentioned earlier I have experience with a setups very similar....Same heads, same cam, with the older style of the pistons you are using. Same specs, different ring pack.
Im not gonna say to not not do the grinding...but I will say with the motor that had basically the same compression on paper (10.25ish), and cam...with around .055 quench I never heard an ounce of detonation. Upon tear down, pistons showed zero issues either...
The same pistons are in my car with the same heads, but no longer using the MP 509. I have a Engle grind on a 106, which doesnt help the detonation issue. Quench is in the high .040s. I can get by with 87 in the cooler months. I have 91 in it right now, but have yet to hear any audible detonation. No hard start issues or any signs of preignition.
Conversely, I had a set of 452s on a flat top motor that had about 10.15 comp. No quench.
Bigger cam than the Engle I currently am using and on a 108. That motor would ping on a hot day on 91 with timing over 34. 2 pistons show signs of light detonation.
So...I think quench is pretty dang important. But, I do believe, based on my experience, that you still get benefit, even if you are in the mid .050s..YRMV.
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: mopar67440]
#1638750
07/21/14 06:11 PM
07/21/14 06:11 PM
|
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
|
Quote:
2. Pushrod length
Having non-adjustable 6-pack rockers, I'll need to verify preload is still within spec. Suspecting .030 was already taken off the heads, now I'm taking .010 more, and keeping within .020-.040 preload, I'm hoping the 3/8 x 9.310 rods I currently have will fall within this preload target.
What was it ?
|
|
|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638752
07/22/14 11:11 AM
07/22/14 11:11 AM
|
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
|
Quote:
The pushrods were 5/16 x 9.31. That was with the original flat top pistons and .040 head gasket. Over the years I picked up 3/8 x 9.31 for the heavier valve springs, but as mentioned I will definately have to revisit this as I'll now be .030 less with .010 off the heads and .020 head gasket.
What is the length of a STOCK 440 pushrod? The factory used a steel shim gasket , .021 , just like all the steel shim gaskets sold now  .
I know this is budget but if you are stuck on using stamped rockers and want specific hyd. preload then I would call Smith Bros and order a set of adjustable pushrods. The last 2 I did have them with stamped rockers because like you I wanted specific preload and it's the only way to get it exact, the valves heights are all a little off from each other unless you had an EXPENSIVE valve job done.
|
|
|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638755
07/25/14 05:49 PM
07/25/14 05:49 PM
|
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
|
Quote:
Must be the difference between a mechanics mentality of time is money, and an engineers attention to detail. 
that pretty much sums it up.
You'll be happier knowing it's right .
Also you should have to worry about rocker geometry much with stock stamped steel rockers , what you are checking is lifter preload and if either of them tell you to put shims under the rocker shafts IGNORE THEM . Get adjustable pushrods ...
|
|
|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638756
07/25/14 06:06 PM
07/25/14 06:06 PM
|
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Quote:
Dropped the heads at the machine shop today to have .010 take off. Pretty confident I'll get the quench to around .043.
Funny...both my life long friend of 40 yrs, who's restored dozens of mopars, and the machinist...both think I'm being way to meticulous. When I mentioned checking rocker arm geometry & possibly ordering shorter pushrods, they both gave me the look of disbelief, and insist I just put it together already. Must be the difference between a mechanics mentality of time is money, and an engineers attention to detail.
The engineers that I dealt with just wanted to see the
end results.. they left it up to me how to get there
|
|
|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638758
07/29/14 03:51 PM
07/29/14 03:51 PM
|
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 74,976
U.S.S.A.
|
Quote:
Well...got the heads back with .010" off, and ready to hit the shop Fri to start assembly. Now that the heads have a nice clean, machined surface, I'll clean the block really good using acetone until the rags are clean before installing the heads. Hopefully get a good seal.
I'm hearing a couple diff schools of thought on using the VHT Copper Cote on the steel head gaskets. A light coat and install and torque when tacky was my thought. Also head bolts to 70 lbs. They are ARP. Mopar suggests 35lbs, then 70, and ARP suggests 3 equal torques to 70.
Copper coat is a good idea and I would torque it like ARP suggests.
|
|
|
Re: Another street/strip 440 rebuild
[Re: mopar67440]
#1638759
07/29/14 07:26 PM
07/29/14 07:26 PM
|
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Quote:
Well...got the heads back with .010" off, and ready to hit the shop Fri to start assembly. Now that the heads have a nice clean, machined surface, I'll clean the block really good using acetone until the rags are clean before installing the heads. Hopefully get a good seal.
I'm hearing a couple diff schools of thought on using the VHT Copper Cote on the steel head gaskets. A light coat and install and torque when tacky was my thought. Also head bolts to 70 lbs. They are ARP. Mopar suggests 35lbs, then 70, and ARP suggests 3 equal torques to 70.
I've done the 3 step for ever.. it works.. then go
back over them at the total torque just to make sure
it hasnt moved
|
|
|
|
|
