Ford 289 Camshaft Manifold Carburetor

[Geoff2]

Heinz,
The engine 'spoke' to you like Moses on the Mountain. Your engine 'likes' manifold connected vac adv [ MVA], which made the engine more efficient, as shown by the temperature drop.

MVA, a most misunderstood subject. Ported VA is useless, an emissions device. Some engines with really big cams can need as much as 50* of idle timing, easily & simply done by using an adjustable VA unit, most of which can add 30* of timing. You need an adj unit because they work with the lower vacuum of bigger cams.

More info here on MVA benefits. Last -3 lines are MOST important. Scroll down to post #6.

www.hotrodders.com/forum/vacuum-advance ... 47495.html

[Heinz1]

Geoff,
thanks for the Link.

[Walter R. Malik]

Geoff,
thanks for the Link.

I also think you need to change the mechanical advance total. Use only 9 distributor degrees; which means 18 degrees at the damper.
35 degrees total and 17 at idle.

I would also look into a "FlowKooler" water pump for your application; which pumps more water at lower RPM.

[Heinz1]

Walter,
thanks for the info, i use your Timing advance settings as a start.
You don´t use vacuum advance?

It is very important that the engine is not overheating at idle and slow Car Speed.
I try different combinations of mechanical & vacuum advance Timing Curves on the Chassis Dyno, see what the engine wants.

Installed a High Flow Pump, but will buy at a FlowKooler Pump and try it.

[BCjohnny]

Full (direct) vacuum advance ....... don't* use non ported, in you application

The higher coolant temps are symptoms of retarded (late) ignition timing from using the 'ported vacuum' source

[*as in almost never]

Should have proof read that, gibberish as originally posted ........ knowing what you mean and conveying it are two separate things

[Heinz1]

Johonny,
no problem, i read your post as: use full vacuum advance and then i wrote i use timed vacuum advance
However, i think full vacuum advance with an adjustable vacuum advance canister and a correct mechanical advance curve should give the best results.
Car goes on the rolling Road / Chassis Dyno, then we will see what works best.

[Geoff2]

Yes, this ^, your last reply.

[BILL-C]

Geoff,
thanks for the Link.

I also think you need to change the mechanical advance total. Use only 9 distributor degrees; which means 18 degrees at the damper.
35 degrees total and 17 at idle.

I would also look into a "FlowKooler" water pump for your application; which pumps more water at lower RPM.

When using the original ford distributor we weld the slot that limits the mechanical advance on the at rest side and file weld back to form a .390 " wide slot. This gives about what Walter Malik likes also. We don't use vac advance with the cam and 10.0-1 CR we build these engines with.

[Geoff2]

Manifold connected Vacuum Advance benefits. Written by Lars Grimsrud, a GM engineer. The last three lines are moooooooost important.

Scroll down to post #6.

www.hotrodders.com/forum/vacuum-advance ... 47495.html

[Walter R. Malik]

Geoff,
thanks for the Link.

I also think you need to change the mechanical advance total. Use only 9 distributor degrees; which means 18 degrees at the damper.
35 degrees total and 17 at idle.

I would also look into a "FlowKooler" water pump for your application; which pumps more water at lower RPM.

When using the original ford distributor we weld the slot that limits the mechanical advance on the at rest side and file weld back to form a .390 " wide slot. This gives about what Walter Malik likes also. We don't use vac advance with the cam and 10.0-1 CR we build these engines with.

YES ... shortening the "at rest" side does make the rotor phasing better, also.

[BILL-C]

Manifold connected Vacuum Advance benefits. Written by Lars Grimsrud, a GM engineer. The last three lines are moooooooost important.

Scroll down to post #6.

www.hotrodders.com/forum/vacuum-advance ... 47495.html

With 8.5-1 CR and an EGR valve, yes, 50* advance at cruise works. A 10-1 CR engine with no EGR with iron heads and marginal octane pump gas 50* is way too much timing. We use light weight springs that deliver full advance by 3k rpm. Most of these types of cars have a lot of rear gear, so they are at 3k rpm at highway cruise speed. If someone does run vacuum advance we advise to not run a stock advance pod with generic 15* advance and instead find one with an adjustable stop and only try a few degrees to begin with and experiment from there. It is very easy damage the engine from detonation playing this game with 10-1 cr and crappy pump gas.

[Geoff2]

Yes, I always use adj vac units with modified engines. This is where MVA often gets a bad name. Some idiot tries to use a stock VA unit with a modified engine that only has 10" of vac at idle. Idle timing varies, & so does the idle rpm, maybe stalls when put into gear if an auto. Said idiot then goes around saying, 'MVA doesn't work....'

50* at cruise [ & more ] is NOT too much in some cases, even with 10:1 CR. It depends on the combo. Pontiac V8s, 10.75:1 with high numerical diff ratio had 56* at high cruise speed.

[Heinz1]

Thanks for all your suggestions,
Walter suggested to install a FlowCooler Waterpump,so i did, Watertemps at idle are lower now, Thank you for the Tip Walter
Friday was the first run on the street at low to midrange rpm & load for a total running time of around 1 Hour.
With the installed 180°F Thermostat the Watertemp is ok so far, engine runs at 190 - 200° F
with Stop and go around our village and up to 62mph / 100km/h on Autobahn.
I used Walter´s and Bill´s suggested Ignition Timing settings as a starting point, work very well.
Best idle with the Holley 600cfm carb is around 900 rpm,12 - 13in hg, idle igniton timing: 15°btdc, max igntion timing: 30° btdc

As Geoff and Bill said,

Some idiot tries to use a stock VA unit with a modified engine that only has 10" of vac at idle. Idle timing varies, & so does the idle rpm, maybe stalls when put into gear if an auto. Said idiot then goes around saying, 'MVA doesn't work....

the Distributor i have has a non adjustable vacuum advance can, which gave to much and erractic vacuum advance.

If someone does run vacuum advance we advise to not run a stock advance pod with generic 15* advance and instead find one with an adjustable stop and only try a few degrees to begin with and experiment from there. It is very easy damage the engine from detonation playing this game with 10-1 cr and crappy pump gas.

So to try vacuum advance i ordered a MSD adjustable Distributor with an adjustable vacuum advance can, should be delivered Wednesday / Thursday.

[Geoff2]

Heinz,
Without even seeing/hearing your engine I can tell you it would like more than 15* at idle because of your low vacuum. With VA disconnected, slowly adv the dist with the engine idling until you get max idle rpm. Will be more than 15*, might be over 30* [ yes, more than 30* at idle ! ]. Whatever it is, that is what the engine needs. Use VA to provide the extra above the 15*.
It will idle smoother, with more vacuum, run cooler & have better off idle response.

How to adj the VA unit. Most adj units can add about 30*. Say from the above test, you got 32*. VA needs to add 17*. You need to make a stop that limits travel so that travel is limited to 17*.
Adjust the Allen Key fully CW. This is the softest spring setting. Check timing with engine idling, in gear if auto, VA connected. Turn AK 2 turns CCW & recheck timing. Keep going 2 turns CCW, checking timing each time, until timing drops or becomes unsteady. Then go back 3 turns CW. Done!

[Walter R. Malik]

Walter,
thanks for the info, i use your Timing advance settings as a start.
You don´t use vacuum advance?

It is very important that the engine is not overheating at idle and slow Car Speed.
I try different combinations of mechanical & vacuum advance Timing Curves on the Chassis Dyno, see what the engine wants.

Depending upon how quickly an RPM the mechanical advance curve starts and ends will determine whether I use a vacuum advance unit or not.
Early"in" curve = no vacuum ... later RPM curve I use vacuum and try both ported and full-time then use whichever runs the best in that particular situation.