Previous Thread
Next Thread
Print Thread
Page 2 of 3 1 2 3
Re: New 440 rebuild - looking for quench [Re: RapidRobert] #2657654
05/21/19 05:32 PM
05/21/19 05:32 PM
Joined: Jun 2008
Posts: 3,714
usa
L
lewtot184 Offline
master
lewtot184  Offline
master
L

Joined: Jun 2008
Posts: 3,714
usa
Originally Posted by RapidRobert
I would suggest: (1) setting the initial with "the vac gauge method" (2) get 34-36 total (initial+slots) useing the right slot pair on the FBO plates (I was not aware there is a prob with em). (3) mix/match spring combo so you are just under the pinging point at WOT up thru the gears on your hottest/driest(most likely to ping) day then (4) plug in the can (if used) & adj it with a 3/32 allen so you are just under the ping point under varying RPM/load conditions in everyday driving on your hottest/driest day & there are differenct cans available that the curve starts at different in hg levels (do your homework there) & you can shorten the total as needed (strips of epoxied feeler gauge) & increase it slightly (file notch wider) as needed. Peoples' hearing varies & there is silent ping so give it a slight cushion & you want to be "reasonably" close to that "pinging" line but never over it. & check that it will crank over when hot & if balky use an ign cutout to get it cranking then switch on the ign or retard the initial (1) deg & retry. Those guys who mod dists can get em in the ballpark or even close but every eng is different & dead on needs alot of adjusting/tweaking.
the FBO plates I have are totally screwed up. near as I can figure the slots are set up for .010" movement equaling a degree. this wrong. .0154" is a degree. .010" is close for the vacuum advance degrees. I measured and checked every way from sunday and they're just plain wrong. I did do some measuring and found a way to use some of the slots , but the plate shifts position at full advance that screws up the desired total. first time I got anything with FBO on it that was wrong. waste of $50.

Re: New 440 rebuild - looking for quench [Re: BSB67] #2657667
05/21/19 06:15 PM
05/21/19 06:15 PM
Joined: Oct 2004
Posts: 1,069
So Cal, USA
Fab64 Offline OP
super stock
Fab64  Offline OP
super stock

Joined: Oct 2004
Posts: 1,069
So Cal, USA
Originally Posted by BSB67
What seems odd to me is that you wanted a motor with 0.040" quench but you got one with 0.060". How did that happen? FWIW, whether its the motor build, or the distributor, the more ownership you take in it, the better the results will be.


It's a very long story, partly my builder's fault, and partly mine. As I said earlier, he was not comfortable with the pistons being that close to the head. In fact,in our initial planning discussions, he didn't really seem to be a big fan of quench - that probably should have been my signal to find someone else. I tried to be very involved, but the build dragged on forever - nearly 3 years!! Near the end of it all, he assembled the engine without letting me know when he was going to do this, and I didn't find out the head gaskets were .050 thick until the engine was back in the car, I was working on dialing it in, and having detonation issues. This was the very first engine I've ever built from scratch and I definitely learned a lot of things that I would do differently if I ever do it again (which - knock on wood - I don't plan to - HA!).

Re: New 440 rebuild - looking for quench [Re: lewtot184] #2657673
05/21/19 06:25 PM
05/21/19 06:25 PM
Joined: Oct 2004
Posts: 1,069
So Cal, USA
Fab64 Offline OP
super stock
Fab64  Offline OP
super stock

Joined: Oct 2004
Posts: 1,069
So Cal, USA
Originally Posted by lewtot184
the FBO plates I have are totally screwed up. near as I can figure the slots are set up for .010" movement equaling a degree. this wrong. .0154" is a degree. .010" is close for the vacuum advance degrees. I measured and checked every way from sunday and they're just plain wrong. I did do some measuring and found a way to use some of the slots , but the plate shifts position at full advance that screws up the desired total. first time I got anything with FBO on it that was wrong. waste of $50.


Thanks for elaborating. I am surprised that their limiter plate has a large center hole, which seems like could allow it to flop around a bit.

I have seen this chart posted in several threads - don't know how accurate it is:

Modifying advance slots
Dist degrees / slot size
6.............. .340
7.............. .355
8.............. .375
9.............. .390
10............ .405
11.5 ......... .420
12............. .435
13............. .445
14............. .460
15............. .475
16............. .490
17............. .505
18............. .520

Re: New 440 rebuild - looking for quench [Re: Fab64] #2657684
05/21/19 06:41 PM
05/21/19 06:41 PM
Joined: Jan 2003
Posts: 14,049
So. Burlington, Vt.
F
fast68plymouth Online content
I Live Here
fast68plymouth  Online Content
I Live Here
F

Joined: Jan 2003
Posts: 14,049
So. Burlington, Vt.
Have you done a cranking compression test?

If the cam has fairly short seat timing, the cranking compression might be fairly high, and/or the dynamic compression might be close to the trouble zone.

There are other items that can contribute to the pinging....... stall(if an auto), rear gearing, engine operating temp, etc.

If the cranking/dynamic compression numbers are high enough where it’s a concern, I’d probably look at slowing the mechanical advance curve down, and employ a small amount of vacuum advance to get the timing up where it should be during part throttle cruise.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: New 440 rebuild - looking for quench [Re: fast68plymouth] #2657689
05/21/19 06:48 PM
05/21/19 06:48 PM
Joined: Oct 2004
Posts: 1,069
So Cal, USA
Fab64 Offline OP
super stock
Fab64  Offline OP
super stock

Joined: Oct 2004
Posts: 1,069
So Cal, USA
Originally Posted by fast68plymouth
Have you done a cranking compression test?

If the cam has fairly short seat timing, the cranking compression might be fairly high, and/or the dynamic compression might be close to the trouble zone.

There are other items that can contribute to the pinging....... stall(if an auto), rear gearing, engine operating temp, etc.

If the cranking/dynamic compression numbers are high enough where it’s a concern, I’d probably look at slowing the mechanical advance curve down, and employ a small amount of vacuum advance to get the timing up where it should be during part throttle cruise.


I've only checked one cylinder so far. I was surpised to see it was 180, then I read that a cam can cause higher cylinder pressures so I'm assuming that's what it is.

My car is an automatic, 2300-2500 stall, with 3.23 rear gears. I'm also running vacuum advance. I know those are all factors. But the only detonation we've seen has come at high rpm, when the secondaries open - and I'm pretty convinced that it is due to too much total mechanical advance.

Last edited by Fab64; 05/21/19 06:49 PM.
Re: New 440 rebuild - looking for quench [Re: Fab64] #2657697
05/21/19 07:02 PM
05/21/19 07:02 PM
Joined: Jan 2003
Posts: 2,085
central texas
K
krautrock Offline
top fuel
krautrock  Offline
top fuel
K

Joined: Jan 2003
Posts: 2,085
central texas
maybe the fuel mix is lean when the secondaries open. i would expect detonation to be a problem with the motor warm and under a low rpm load.

Re: New 440 rebuild - looking for quench [Re: Fab64] #2657704
05/21/19 07:13 PM
05/21/19 07:13 PM
Joined: Jan 2003
Posts: 14,049
So. Burlington, Vt.
F
fast68plymouth Online content
I Live Here
fast68plymouth  Online Content
I Live Here
F

Joined: Jan 2003
Posts: 14,049
So. Burlington, Vt.
So, how low does the total timing have to be to keep it out of detonation?

For California 91 swill, I’d have built it with .040-.045 quench, about 9.75cr, and a cam that would put the dynamic Cr solidly under 8.0.

Which I’m sure would have broadened the tuning window with regards to the timing curve.

Edit...... plugging some numbers into the uem calculator....... it takes a cam a little longer than one might expect to get the numbers to work out.
For example, a 220@.050 cam intalled at 110, with 9.75cr has the DCR at 8.3.
Bumping the CR to 10.17 puts the DCR at over 8.6.

I haven’t tried pushing the envelope on that type of build....... when I hear “pump gas”...... I err on the conservative side.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: New 440 rebuild - looking for quench [Re: fast68plymouth] #2657728
05/21/19 08:06 PM
05/21/19 08:06 PM
Joined: Mar 2011
Posts: 2,597
Michigan
T
Transman Offline
master
Transman  Offline
master
T

Joined: Mar 2011
Posts: 2,597
Michigan
You mention detonation at higher engine speed - does it rattle when the carbs open then subside or does it continue to rattle until you tip out of the throttle ?

Re: New 440 rebuild - looking for quench [Re: Transman] #2657742
05/21/19 08:35 PM
05/21/19 08:35 PM
Joined: Jan 2003
Posts: 27,421
Balt. Md
3
383man Offline
Too Many Posts
383man  Offline
Too Many Posts
3

Joined: Jan 2003
Posts: 27,421
Balt. Md
I can tell you what I run. My quench came out around .046 on my 440/493 with a solid flat tappet cam and Indy EZ heads. My comp ratio is 10.6 and my cam is a custom grind from Dwayne Porter (Fast68Plymouth) that is .585 & .592 lift with 264 & 270 @ .050 on a 110 LSA. I run 36 total advance all in by 2000 rpm. I have no ping at all and have never had any ping. I have no vacuum advance as my dist is a Mallory race unit and has no vacuum advance. I use the Felpro .039 head gaskets. I understand where you are coming from since good quench helps fight ping (detonation) as when I built my eng that was one factor I wanted to be around .045 give or take a few thousandths because I run on 92 pump and did not want any detonation problems so I made sure I had decent quench. I would have thought your eng builder would have wanted to build decent quench into your eng. .060 is not the worst but I shot for .045 as that's a good quench to me and not to close to the piston to get worried with a steel rod eng. A good build in todays world is a zero deck flattop piston eng with .040 head gaskets and a closed chamber head. If you have .050 gaskets then going to the Felpro .039 would get you around .049 quench down .011 from .060. But the only .050 head gasket I know of would be a custom made Comedic head gasket. Ron

Re: New 440 rebuild - looking for quench [Re: 383man] #2657766
05/21/19 09:50 PM
05/21/19 09:50 PM
Joined: Nov 2003
Posts: 35,964
Lincoln Nebraska
R
RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 35,964
Lincoln Nebraska
I had no idea the FBO plates had an issue. Thanks for the heads up! I will see about reducing the center hole & seeing how much adv the slots do give.


live every 24 hour block of time like it's your last day on earth
Re: New 440 rebuild - looking for quench [Re: RapidRobert] #2657775
05/21/19 10:17 PM
05/21/19 10:17 PM
Joined: Jan 2003
Posts: 16,375
D
dogdays Offline
I Live Here
dogdays  Offline
I Live Here
D

Joined: Jan 2003
Posts: 16,375
I was one of the ones pushing for tighter squish..I prefer to call it squish because I believe that's the mechanism that benefits everything.
So when I took apart my Mom's '86 318 I was disappointed to see the pistons down in the hole something like 0.055". I used the Mr. Gasket thin gaskets which are 0.028" compressed. Do the math, the distance seems to be huge. But the results speak for themselves. The engine comes in right at 9:1 and using a stock 360 cam I am running it on 85 octane in the mountains which switches to 87 down in the flats. In other words, pump regular. Running 35 degrees total with a high perf advance curve I NEVER have detonation. Even running it down into Phoenix while still jetted for 6,000 ft in the 110 degree summer. And mileage jumped from 16 to 22!
This is the long way around the barn to say I don't think your 0.060" squish is hurting things. I have a feeling you had an idea of what your new engine would feel like and it doesn't come up to your expectations.

We have no dyno numbers or ETs or quarter mile speeds with which to judge what the engine is actually putting out. Before you jump into the deep end, maybe we should hear about the numbers it can generate.
Lord Kelvin said approximately that if you can't or don't measure it, you don't know anything about it. This may sound a little hard core but you may hear the same thing on this board, when people say until you show up with ETs don't bother.

R.

Re: New 440 rebuild - looking for quench [Re: krautrock] #2657777
05/21/19 10:19 PM
05/21/19 10:19 PM
Joined: Oct 2004
Posts: 1,069
So Cal, USA
Fab64 Offline OP
super stock
Fab64  Offline OP
super stock

Joined: Oct 2004
Posts: 1,069
So Cal, USA
Originally Posted by krautrock
maybe the fuel mix is lean when the secondaries open. i would expect detonation to be a problem with the motor warm and under a low rpm load.


Yes, we had to bump the outboard jets all the way up to 85 (they previously were 79 & 80). I'm hoping to reduce them back down at least some when I limit the total advance.

Re: New 440 rebuild - looking for quench [Re: fast68plymouth] #2657780
05/21/19 10:22 PM
05/21/19 10:22 PM
Joined: Oct 2004
Posts: 1,069
So Cal, USA
Fab64 Offline OP
super stock
Fab64  Offline OP
super stock

Joined: Oct 2004
Posts: 1,069
So Cal, USA
Originally Posted by fast68plymouth
So, how low does the total timing have to be to keep it out of detonation?

For California 91 swill, I’d have built it with .040-.045 quench, about 9.75cr, and a cam that would put the dynamic Cr solidly under 8.0.

Which I’m sure would have broadened the tuning window with regards to the timing curve.

Edit...... plugging some numbers into the uem calculator....... it takes a cam a little longer than one might expect to get the numbers to work out.
For example, a 220@.050 cam intalled at 110, with 9.75cr has the DCR at 8.3.
Bumping the CR to 10.17 puts the DCR at over 8.6.

I haven’t tried pushing the envelope on that type of build....... when I hear “pump gas”...... I err on the conservative side.


The initial timing is currently at 10 degrees. With approximately 26 degrees total mechanical, that puts me at around 36 total.

And my original intention was to have .040 quench, and a c/r around 10.1:1

I'm not familiar with dynamic compression ratio - I'll have to study up on it. Unfortunately, I don't know the exact cam specs (Mr. Six-pack doesn't publish them).

Re: New 440 rebuild - looking for quench [Re: Transman] #2657782
05/21/19 10:23 PM
05/21/19 10:23 PM
Joined: Oct 2004
Posts: 1,069
So Cal, USA
Fab64 Offline OP
super stock
Fab64  Offline OP
super stock

Joined: Oct 2004
Posts: 1,069
So Cal, USA
Originally Posted by Transman
You mention detonation at higher engine speed - does it rattle when the carbs open then subside or does it continue to rattle until you tip out of the throttle ?


It would rattle badly until you let off the throttle. Note, at 10 degrees initial, it is no longer detonating.

Last edited by Fab64; 05/21/19 10:24 PM.
Re: New 440 rebuild - looking for quench [Re: Fab64] #2657848
05/22/19 03:12 AM
05/22/19 03:12 AM
Joined: Aug 2003
Posts: 39,976
Bend,OR USA
C
Cab_Burge Offline
I Win
Cab_Burge  Offline
I Win
C

Joined: Aug 2003
Posts: 39,976
Bend,OR USA
What brand and heat range, part number on the plug, plugs are you using?


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: New 440 rebuild - looking for quench [Re: Sniper] #2657891
05/22/19 08:46 AM
05/22/19 08:46 AM
Joined: Jan 2008
Posts: 1,123
Minn
S
SportF Offline
super stock
SportF  Offline
super stock
S

Joined: Jan 2008
Posts: 1,123
Minn
Originally Posted by Sniper
Originally Posted by SportF
Originally Posted by Jerry
your quench is fine. why do you think the engine is under performing.

couple of things to look at...
1. ignition timing, where is it set?
2. headers too large
3. air fuel ratio? have you had this checked?
4. what springs in the secondaries?
5. what advance springs in the distributor




I have never heard anybody at the dragstrip worry about quench. Jerry above here has some great points.


Never heard the OP mention a dragstrip. In fact, when replying to the cam specs he said street car.



I thought some things at the strip would apply to the street. But, I may have missed it, but timing being critical, was the dampener mark checked to TDC?


Re: New 440 rebuild - looking for quench [Re: Fab64] #2657896
05/22/19 08:53 AM
05/22/19 08:53 AM
Joined: Jun 2008
Posts: 3,714
usa
L
lewtot184 Offline
master
lewtot184  Offline
master
L

Joined: Jun 2008
Posts: 3,714
usa
Originally Posted by Fab64
Originally Posted by Transman
You mention detonation at higher engine speed - does it rattle when the carbs open then subside or does it continue to rattle until you tip out of the throttle ?


It would rattle badly until you let off the throttle. Note, at 10 degrees initial, it is no longer detonating.
i'm going to guess that you were upping the initial timing beyond the 10 degrees and were probably doing close to, or more, than 40 at WOT. those distributors have a staged centrifugal advance curve. I use the staged thing in both my cars but it's a little tricky, especially with a vacuum advance. that cam you have has a short duration intake lobe and i'm surprised the cranking compression isn't noticeably more than 180psi. could have a wide LSA. if you do a 9 degree plate it won't be simple to keep the staged centrifugal curve and vacuum advance without a short heavy spring. you'll probably have to do a full centrifugal advance without the vacuum can simply because the proper springs aren't available anymore. something I found out when I was doing the 6pak thing is that the "feel good" advance curve actually slowed my car down at the track about 2 tenths due to extra wheel spin. my last outing, some years back, was cut short simply because I forgot I had the "feel good" distributor in the engine.
I also was plagued with oil and water contamination in the chambers that limited total advance to 34 degrees. since then I've found that 37 degrees total, with clean chambers, seemed to work quit well.

Re: New 440 rebuild - looking for quench [Re: lewtot184] #2657910
05/22/19 09:29 AM
05/22/19 09:29 AM
Joined: Jun 2008
Posts: 3,714
usa
L
lewtot184 Offline
master
lewtot184  Offline
master
L

Joined: Jun 2008
Posts: 3,714
usa
finding an industrial engine pick-up plate makes setting up a full centrifugal distributor easier.

100_0439.jpg
Re: New 440 rebuild - looking for quench [Re: lewtot184] #2657921
05/22/19 09:45 AM
05/22/19 09:45 AM
Joined: Jan 2003
Posts: 14,049
So. Burlington, Vt.
F
fast68plymouth Online content
I Live Here
fast68plymouth  Online Content
I Live Here
F

Joined: Jan 2003
Posts: 14,049
So. Burlington, Vt.
Quote

And my original intention was to have .040 quench, and a c/r around 10.1:1


If you used the same cam you have now, the cranking pressure and DCR would be higher than what you have now....... would probably ping even more.

There’s nothing magic about 10:1 and .040 quench running on pump gas........you also have to pay attention to the DCR.
If the DCR is too high...... it’ll ping.

My experience with the metering plates that utilize replaceable jets is....... the required jet size to maintain the same a/f ratio as the OE metering plate you’re replacing is....... it will require a step up of several jet sizes.

Easily confirmed with a wide band o2 sensor and gauge in the car.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: New 440 rebuild - looking for quench [Re: fast68plymouth] #2657926
05/22/19 10:01 AM
05/22/19 10:01 AM
Joined: Oct 2011
Posts: 559
Idaho
L
LaRoy Engines Offline
mopar
LaRoy Engines  Offline
mopar
L

Joined: Oct 2011
Posts: 559
Idaho
Originally Posted by fast68plymouth
So, how low does the total timing have to be to keep it out of detonation?

For California 91 swill, I’d have built it with .040-.045 quench, about 9.75cr, and a cam that would put the dynamic Cr solidly under 8.0.

Which I’m sure would have broadened the tuning window with regards to the timing curve.

Edit...... plugging some numbers into the uem calculator....... it takes a cam a little longer than one might expect to get the numbers to work out.
For example, a 220@.050 cam intalled at 110, with 9.75cr has the DCR at 8.3.
Bumping the CR to 10.17 puts the DCR at over 8.6.

I haven’t tried pushing the envelope on that type of build....... when I hear “pump gas”...... I err on the conservative side.


Dog-gone-it I like the way you think.

Page 2 of 3 1 2 3






Powered by UBB.threads™ PHP Forum Software 7.7.1