Engine load from auxiliary equipment

[Wietse]

But in general, those aux. drive can be classed as load right, same as a tight converter does once in gear?

I am fishing out all potential inconsistencies, I installed a new timing chain kit and immediately after start up noticed it ran quite better.
As time goes by there will be some more slack on the chain and it can degrade again but it 100% improved.
Next is to install a stopper bushing on the distributor shaft that will act as a stopper for the intermediate shaft (pump drive shaft) to float upwards and cause ignition timing deviation.

I also have a set of Rhoads variable lifters lying that I still want to install as well, this to take out some cam duration.
I just have a little fear over running new lifters on the existing camshaft.

 

[Geoff 2]

Comparing 050 duration between sol & hyd lobes. For tight lash, add about 8*; for large lash [ 0.032" ], add 15*.

 

[Geoff 2]

Wietse,
[1] Cannot answer your question about specific HP loss due to accessories, but with small 4 cyl engine cars, you can feel the engine note change by just switching on the headlights. That is the extra load the alt is generating to keep the battery charging with the h/light load.
[2] The Accel adj VA unit [ pretty sure ] is one that has the dreaded spacer inside the spring, limits total travel. Worth prising apart & removing the spacer, otherwise it will limit VA tuning options.

 

[Wietse]

Not wondering in specific hp loss, just want to know if all this is enough to create a load that will fight the engine at idle.
I did not come across any other adjustable VA can that will fit my MSD distributor.
Regardless, I am pretty sure it will allow quite some more vac advance compared to the stock MSD unit.

 

[Geoff 2]

Doubt that a large engine like a 440 will be affected at idle by accessory load because it is making a lot more HP at idle to handle the load, compared to a small 4 cyl engine.
With the Accel VA. Screw in the Allen key fully in both directions. If the plunger arm locks up, it has the dreaded spacer.
I tried to adapt one of these adj VA units to the MSD dist & operation was erratic due to the MSD mounting for the VA.

 

[lewtot184]

What cam specifically? I know you know it can make a big difference. And, is that in neutral or in gear vacuum?

engle k65 camshaft. installed at 106cl. 14"hg@900rpm in neutral. 9.5"hg@600-650rpm in gear. i use a 1966 street hemi converter, no mods to it, and it is somewhat tight for the cam. i have a mopar electronic distributor that i've swapped some parts around in it. i use a 9 degree plate a light and heavy advance springs with a 9 degree vacuum advance. initial timing is 18 degrees.

i know i didn't elaborate much in my initial comment but my intent was to show a difference between lobe separation and a solid tappet. my cam has about 75 degrees overlap on the seat and does close the intake valve a little later than i'd like but the whole thing is reliable and low maintenance so there's no real driver to make a change. i believe tight lobe LSA and hydraulic tappets are just not vacuum friendly. i also believe most tune-ups for street cars aren't idealized either.

 

[lewtot184]

On a tight lash cam maybe. 8 to 10 degrees is not uncommon.

i was having some cam issues quit a while back and i remember talking to Mark Engle about a cam swap; going from hrdraulic to solid. the way i understood this the 8 degree thing was in reference to seat timing not .050". the real issue with comparing solids to hydraulics is the advertised ratings are where they are measured. with solids some are measured at .015", some .020" and racer brown stuff may be anywhere. closing ramps confuse things too whether it's solid or hydraulic. i don't believe there is a "blanket clause" for all grinds concerning the "8-10 degree" thing.

 

[Wietse]

engle k65 camshaft. installed at 106cl

I am pretty sure that is a similar profile as my cam, mine is a Hughes Engines HE3844BL.
I had to look it up but from what I was told is this cam uses the Engle profiles K-60HYD .534" 285° 238° 152° (intake) and K-62HYD .539" 294° 244° 156° (exhaust).
So advertised duration is 285/294 and mine is installed at 105* ICL.
I am using 1.6 ratio rockers so my lift is a little higher than mentioned above, believe it was .572/.576".

 

[dvw]

I may have missed it. What is the compression ratio? Low compression plus overlap = low vacuum. The cam may need even more advance than the current 105 ICL. If it is really at 105. With good calibration it should idle fine warm. Heck my racecar will idle at 900 in gear no issue, cam is [email protected]". I'm assuming you want it to idle cold with no throttle input? Why not bump the linkage up with an old style AC solenoid.
Standard Motor Products ES110 Standard Motor Carburetor Idle Stop Solenoids | Summit Racing
Doug

 

[Wietse]

CR is about 10.5, cranking pressure is at 165 psi.
I have measured it and it is at 105* ICL.

When i opened up the timing gear cover the first time since i owned the car i found the gear dot-to-dot not lining up, the cam was advanced 1 tooth....accidental or on purpose i don't know. (IRCC that is a 14* advance!!)
I ran like a rocket and had 200 psi cranking pressure, at that time i had the same shitty vacuum and same problems as i have now.

Another thing i need to consider is the distributor shaft, it might be very sloppy in the oil pump drive gear slot, combined with any allowable float and i will get a badly fluctuating timing.
Maybe this is more likely to be the source?
As mentioned i want to try a stopper bushing on the distributor shaft and maybe weld up the distributor shaft key to remove excessive play.

 

[lewtot184]

I am pretty sure that is a similar profile as my cam, mine is a Hughes Engines HE3844BL.
I had to look it up but from what I was told is this cam uses the Engle profiles K-60HYD .534" 285° 238° 152° (intake) and K-62HYD .539" 294° 244° 156° (exhaust).
So advertised duration is 285/294 and mine is installed at 105* ICL.
I am using 1.6 ratio rockers so my lift is a little higher than mentioned above, believe it was .572/.576".

those lobes are rated at .008", so if your trying to cross reference to .006 (seems to be the common number anymore) than seat timing is close to 290/298. i think the real difference between what i have and yours is area under the curve and i've found that can have a noticeable effect on vacuum. what i've found on aftermarket market rockers is their ratings aren't consistent with actual numbers. your probably at 1.65. 1.65 vs 1.5 will add about 9 degrees at .200" lift. so, if your advertised .200" numbers are 152/156 then now they are closer to 160/165. you have a lot of area under the curve in relationship to seat timing. the higher ratio (1.65) will act like a step more cam at the valve in this case when compared to 1.5. i've found that by just going from a 1.5 to a true 1.6 rocker on a stock type cam will reduce vacuum by 1"hg. what i'm getting at is there is a stack up of issues that work against low rpm vacuum; LSA, hydraulic tappet, high ratio rockers, area under the curve. the 238/244 cam is far from being a mild cam. 22 degrees overlap at .050" with the hydraulic tappet will take some low rpm starch out of vacuum. i suppose the real issue is do you need 14-15" of vacuum to run accessories? if not then i'd just play with the tune up.

 

[lewtot184]

CR is about 10.5, cranking pressure is at 165 psi.
I have measured it and it is at 105* ICL.

When i opened up the timing gear cover the first time since i owned the car i found the gear dot-to-dot not lining up, the cam was advanced 1 tooth....accidental or on purpose i don't know. (IRCC that is a 14* advance!!)
I ran like a rocket and had 200 psi cranking pressure, at that time i had the same shitty vacuum and same problems as i have now.

Another thing i need to consider is the distributor shaft, it might be very sloppy in the oil pump drive gear slot, combined with any allowable float and i will get a badly fluctuating timing.
Maybe this is more likely to be the source?
As mentioned i want to try a stopper bushing on the distributor shaft and maybe weld up the distributor shaft key to remove excessive play.

as far as distributor goes i've found that spark scatter can be more of a worn out intermediate shaft bushing than anything. putting collars on the bottom of the distributor shaft does nothing, the thrust on the intermediate shaft is down, not up, due to the helix on the gears. a loose intermediate shaft bushing will let the shaft gear drift to the rear of the engine. a small drift can account for a few degrees. i've noticed high valve spring rates and fast lobes (mostly roller stuff) can create some low rpm scatter. those intermediate shaft bushings seem to be all over the place as far as i.d. is concerned. anyhow that's the first place i'd check. i got out of that shaft collar nonsense years ago. it's all about the helix on the cam and intermediate shaft gears.

 

[Nxcoupe]

Yes it does pull about 6* more in as it is on manifold vacuum. (it is the stock v-can that came with the MSD RTR distributor)


It does not indeed, for that I will have to change over to the complete Hyper spark setup.


Below is what I mean, others with similar cams get more vacuum.



Yes, the transfer slots were exposed
I tried drilling holes, installed a Wagner adjustable PCV valve to be able to control the air I am adding but nothing real successful.
The EFI has the IAC valve (Idle Air Control), when the engine is cold (coolant below 160*) it supposed to bump the idle to high idle.
With the IAC at 100% open it cannot even reach the normal (low) idle of 900 without me nursing the throttle. (I already know to hold the throttle at 2-3% open to maintain it, can see it on the EFI screen what the throttle position is)

I bought an Accell adjustable v-can I want to try setup once the weather becomes better and see if I can let it pull in a lot more vac. advance as I am stuck with total timing.
Currently have 18* initial and 18* mechanical advance so total timing is already on the limit for a BB, I want to reduce the initial to 16* but will need more vac. advance to do so.

With the iac at 100%, it should be idling at 2k or so. You need to adjust your base idle when the engine is up to temp so the iac is showing close to 0. Then it will operate as designed when it's cold. Also, your fuel modifiers should be adding fuel so it stays running on its own.

 

[Don Frelier]

CR is about 10.5, cranking pressure is at 165 psi.
I have measured it and it is at 105* ICL.

When i opened up the timing gear cover the first time since i owned the car i found the gear dot-to-dot not lining up, the cam was advanced 1 tooth....accidental or on purpose i don't know. (IRCC that is a 14* advance!!)
I ran like a rocket and had 200 psi cranking pressure, at that time i had the same shitty vacuum and same problems as i have now.

Another thing i need to consider is the distributor shaft, it might be very sloppy in the oil pump drive gear slot, combined with any allowable float and i will get a badly fluctuating timing.
Maybe this is more likely to be the source?
As mentioned i want to try a stopper bushing on the distributor shaft and maybe weld up the distributor shaft key to remove excessive play.

Again:
Strongly suggest you get a locked out distributor and let the EFI control the timing.
If it were myself I wouldn't do anything with the distributor you have now.

 

[lewtot184]

i have a hughs/engle 30/38 cam laying around and i looked at the notes i have on it when i stuck it in a block and measured it. on the "38" lobe it picked up 6 degrees on the seat when measured at .006" vs .008". i believe the "44" lobe profile would be similar. if so then the seat overlap on the 38/44 should be around 80 degrees. 80 degrees should be lumpy, especially with a hydraulic tappet. ignition curve would be critical for street operation. i know i must've built 20 or more different curves for my car before i found something i liked.

 

[Geoff 2]

The info in post #22 comes from Crane Cams & is correct, bearing in mind that because of lobe profile differences, there can be a degree or two of difference.
The 0.006-8" adv numbers for hyd cams are pretty useless, due to varying bleed down rates of hyd lifters, which are also affected by rocker ratio, oil viscosity & spring tension.

 

[lewtot184]

The info in post #22 comes from Crane Cams & is correct, bearing in mind that because of lobe profile differences, there can be a degree or two of difference.
The 0.006-8" adv numbers for hyd cams are pretty useless, due to varying bleed down rates of hyd lifters, which are also affected by rocker ratio, oil viscosity & spring tension.

i looked at my crane catalog trying to clarify your point. if i understand correctly what is written crane is alluding to the fact that different cam grinders rate their advertised numbers at different lifts (crane was .0042", compcams .006", engle .008", racer brown could be anything) and using .050" lift puts everybody on the same sheet of music. i was referencing that difference between hydraulic and solid and how they can't be compared using advertised numbers. so i'm not sure where the confusion is but if you have something in the crane catalog i've missed i'd be interested in reading it.

 

[Geoff 2]

Info was in an old [ 70s-80s ] catalog. Will see if I can dig it up. Not in the latest catalog I have.
It is not related to adv duration because the lift varies. Crane [ now defunct ] used 0.004", 0.0042", 0.003" lift for adv duration of hyd lobes.
Using 050, well it is 050.....

 

[Wietse]

Strongly suggest you get a locked out distributor and let the EFI control the timing.
If it were myself I wouldn't do anything with the distributor you have now.

From what I know I need to get the complete Hyperspark kit. (distributor, control box and coil)
I did some reading on this in the past and a lot of people had problems with this setup, maybe more likely due to not following instruction than the system "not working out of the box".
I did verify and my RTR distributor (MSD 8387) has the option to lock the mechanical and vacuum advance which gives me the option to reuse it.
Aside from that, what more would I need to have the Sniper controlling the ignition timing, do I need one of those MSD control boxes?

I am not against EFI spark control, but so far I did not find the reason to offset the $800 to buy it and get it here (shipping, 21% import tax which results in about $1150-1200) for the Hyperspark kit against having automatic control if I can get a curve on my current distributor that works well.

With the iac at 100%, it should be idling at 2k or so. You need to adjust your base idle when the engine is up to temp so the iac is showing close to 0. Then it will operate as designed when it's cold. Also, your fuel modifiers should be adding fuel so it stays running on its own.

Yes it should for sure.
It is at 100% open when cold and not able to bring the rpm up, once at normal operating temperature the IAC position is about 5-8% during idle of 900 rpm.
I tried the AFR for idle over all range, all I know is that it needs a little rich mixture to run "best" which is 13.2 IIRC.
I know what it should do but it does not, there are underlying things I need to find out, either aux. load, erratic spark due to too much clearance on the drive or something else.

putting collars on the bottom of the distributor shaft does nothing, the thrust on the intermediate shaft is down, not up, due to the helix on the gears

I've seen quite some people mention that after installing a collar they had never seen any deviations in timing to what the had before installing it.
If you have a bumpy idle there will be a short moment where the cam gear speed changes, enough to get slack on the intermediate shaft gear, which in turn will back up against the teeth.
An continues or increasing load applied and that shaft will not move indeed as you state due to the gear cut.

 

[Don Frelier]

If you can lock out the MSD, then use the one you have. I would look for advance around 30 degrees or more at idle.
With a larger cam you may find that idle afr needs to be a little richer maybe 13.8 or Even lower. Get the IAC to read as directed and it should run as well as your going to get it