I have just rebuilt my 400m with 9.5to1 pistons 4bbl intake and a
comp cam(32-221-3). I am having some trouble trying to stop the pinging and overheating. When I bought the cam I was told that this particular cam likes to he advanced 4dagrees so that how I set it on the timing set. But what I found out from comp cams is that this cam has a 4 degree advance ground into it. So this is what I have tried with my ignition timing they are all advanced. I am running 90 octane fuel. <O</O
2 degrees overheating/small amount of pinging<O></O>
5 degrees less overheating/more pinging<O></O>
7 degrees more pinging<O></O>
9 degrees more pinging<O></O>
11degrees more pinging<O></O>

 

https://www.ford-trucks.com/forums/6...t-up-myth.html

are you sure the head gaskets are oriented to the "FRONT" like they say on them?

the cam being over-advanced shouldn't be causing any overheating issues. i ran an engine with the timing set skipped a full tooth advanced and it didn't even run warm.

correct type thermostat? did you top off the radiator after the Tstat opened up?

looks like it's time to pull it apart. i'd set the timing gears to -4 if you're not going to degree it.

 

Hello and Welcome to FTE!

From the reading I have done on this site, your main problem is the cam is heavily advanced and that can cause both of the problems you are encountering. Currently, your cam has 4 deg. adv. and the chain is set at 4 deg. adv. so that gives a net 8 deg. advance. This makes the valve timing off so far it can cause the engine to run hot. I am not sure what it is doing to your dynamic compression, but I can't imagine it is helping things. I am sure others on this site could answer that question better and I would be pleased if they did.The pinging is aggravated by the advanced position of the distributor as it is driven by the cam. So at 2 degrees indicated on the damper, your distributor is 10 degrees advanced without factoring in the centrifugal advance when the motor is at speed.
Eventually, the chain will need to be set to 4 deg. retarded to bring the cam to "straight up" which the 400 prefers. (In case you were wondering, the cam has the 4 deg. adv. in it to nagate the factory chain which was built 4 deg. retarded.) In the mean time you could try the procedure shown in this link http://www.bob2000.com/dist.htm to limit the total advance and reduce the pinging. Also set the timing to zero or a few degrees retarded (ATDC) and see if that helps. Best of luck, sorry to be the bearer of bad news, and keep up the american spirit by enjoying good old american iron!

 

I agree with 79fordnut, Gary touched on it, too w/the link, your timing is probably causing overheating, but don't forget the "break-in" period will cause heat as it "wears in" by way of friction with tighter tolerances.

 

For your 400, -no M.

The cam being advanced has no effect on the distributor timing. 2° on the balancer is still 2° on the timing not 10°. Remember the ignition timing is set off the TDC on the balancer. The distributor can be set in anywhere it will fit and the wire positions can be changed and the ignition is still timed off the balancer (providing the balancer is in good condition and has not slipped).

The cam timing is relative to the crankshaft. The crank determines the piston positions. The cam determines the valve events.

9.5:1 compression is a lot of compression if you are running open chamber heads, no quench, and without a bigger cam to reduce the dynamic compression. You may need race gas, E85, or propane for fuel.

Cam specs:
Part Number 32-221-3
Engine 1970-1982 Ford
351ci-400ci
351C, 351M-400,
8cyl.
Grind Number FC 268H-10
Description Intake Exhaust
Valve Adjustment 0 0
Gross Valve Lift 0.494 0.494
Duration At 0.006 Tappet Lift 268 268
Valve Timing At 0.006
------- Open Close
Intake 28 60
Exhaust 68 20
These Specs Are For The Cam Installed At 106 Intake CL
Intake Exhaust
Duration At 0.05 218 218
Lobe Lift 0.2853 0.2853
Lobe Separation 110

 

there are too many performance grinds to count that run the valve events much further advanced than the 8* taylor78's cam is at, and they don't overheat.

looking at the symptoms again, the overheating decreases with more ignition advance. no big deal, to be expected. retarded ignition timing will run hot.

 

Thanks Torque, for setting me straight on the timing. I tried to think it all the way through B4 I wrote it.

For sure, fresh engines do run warmer until they wear in a little and for best overall performance the cam should be set to "straight up".
Taylor78, keep reading, run a couple of searches and we will all learn a few things. Do you have a good temp. gauge that will tell us exactly how hot the engine is running?

 

I've been studying dynamic compression for a bit now and you are pushing it a bit regardless of timing chain IMO. Unless your running aussie or alum heads with quench chambers. But if you had installed the cam straight up I bet you would be ok as far as ping. From what i understand (and jump all over it if i'm wrong) your closing the intake valve 8* sooner than the cam is designed...if it is designed to be installed with a factory 4* retarded chain. That would have a marked impact on the dynamic compression similar to a milder cam. I bet it would be ok having the cam set at 0*.

With heads that offer quench and 9.5:1 it appears that the 268 cam would easily allow the use of 87pump due to quench but you just can't get good quench out of the stock heads regardless of piston. your cam has quite a bit of intake duration which is what you need with higher compression.

I could be worng (obviously) but it seems that you need to reset the cam to straight up...0* and try again.

 

Thanks for all the help.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

I talked to comp cams and they recommend that the timing set be at 0*.<o></o>

What is the success rate on taking off the timing cover without removing the oil pan and sealing it up after? It is a 4 piece oil pan gasket.<o></o>

I did run this truck for 800 kms(480mi)with no overheating at 10*.I then towed 5000lbs on flat ground 100 kms (60mi) with no overheating just pinging. I then towed the same load a shot distance at 5* and it got hot real hot even at an idol which it had no problem there before.<o></o>

I am planning on changing the timing set to 0*. I hope that this will help me to zero in on the right ignition timing with no pinging or overheating.<o></o>

 

I agree to set the cam first. Take a good look at your overall timing curve including vacuum advance. Also too small a radiator or other cooling problems will compond things.
In the end if you still have problems consider water/methenol injection. It worked wonder for me.

 

A nice, smooth advance curve should cure your pinging problem.

If you decide to get a new distributor, consider our custom curved Duraspark Distributor built with our new Full Length Oil Impregnated Bronze Bushing. The full length bushing improves timing stability and spark scatter. If stock appearance is not an issue, take a look at our one piece D.U.I. Distributor. Whether you choose the Duraspark or the D.U.I., we curve each on a distributor machine based on your engine combination. Please see them at:

http://www.performancedistributors.c...stributors.htm


Also, there is now an excellent installation article on the D.U.I. Distributor on the Ford-Trucks.com site at:

https://www.ford-trucks.com/article/idx/0/358/article/DUI_Ignition_Installation_In_A_Ford_351W_V8.html

 

The timing cover can be removed without the pan. Save the rubber seal, cut the pan gasket at the edge of the block. Clean everything up and use a little silicone to replace the pan gasket and seal the cover.

 

thank for all the help

 

I had the backfiring problem on my truck(now it won't crank), and it would backfire at idle. The distributor is pointing at #1 plug at TDC, is it suppose to be @ 6 degrees BTDC or so?

 

6 should be fine