put my flathead on the dyno today

I had a couple plug wires crossed and it acted like your problem...

 

I'm running an old Mallory dual point with pertronix, and love it.

Rich

 

Here in italy everything is very complicated . Nobody knows flatheads, and US motors are known and reowrked by very few talented mechanics.
Advance was 15 degrees at about 1000 rpm.

 

I offer one suggestion and that would be to hook up a scope at the motor to check the plug wire resistance and ignition while doing the dyno pulls. This will show if you have any wires-dizzy-condenser or point problems which would eliminate that part of your system allowing you to test elsewhere for problems. Good luck

 

With all the input that comes in I can only come up with a couple things that could or could not be part of the problem. Valve adjustment to tight if it were to loose you would find that by the noise along, cam to crank timing which is pretty much dummy proof unless you had a screwed up cam gear. If you don't find any better results after checking all of that and the points are good start again with a different single carb. I sure would love to have a dyno to work off of I'd be trying all sorts of stuff. keep us posted.

 

Send me a ticket...I'll come debug it!

 

I'll agree, send a ticket to Bruce, he does need a vacation.......

and yet I do believe it's a timing problem....If not the Mallory internals, you might have the dizzy in one or two gears behind in rotation.....as it's running fine at idle but sputters as the rpm's come up making me think it's loading up. Check the plugs again to see what they look like.....wet....or white.

 

Motts, plugs are very black. What do you mean in your post? Everything seems ok, starts immediately, nice idle, but everything is over at 2500 rpm.
Bruce, depends on air fares ....it's low season.....we can talk about this. If you bring the spares and knowledge, we can talk.....I live in Milano....

 

Look first to your points and the connecting conductors; if the engine has run, the Mallory points will be closing again. Condenser is VERY likely failing and is certainly not well grounded...throw on a condensor from ANYTHING else! Get a HAMB dealer to send you NAPA points and condenser, meanwhile be vigilant. The original small parts are the worst China could manage. Black plugs usually mean rich carb, but also come from your very likely bad spark. If those connectors are near shorting out, you are likely running with a continual low level misfire.
Oh, did I mention that recent Mallorys sometimes have problems?

 

Sure, get your ignition sorted, but then LISTEN TO THIS GUY:

 

As meny of you has getting trouble from a Mallory dual point, same here!!. But the good old ones works well!

As Madmax says: The French blocks has to be ported alot in order to get the rpm, and power. Many of them has an original releiving, so just focus to go bananas in the inntake and exhaust ports!!!!


..............................
Taildragger&fenderless

 

Just for some insight into the French blocks ....

I bought a French block and main caps to build that has resided in my 40 Ford coupe now for over 6 years. It has a machined releif in the block and to my understanding, most if not all of the French blocks are the same way. Mine was cast in 1986 if that helps at all.

 

You really need to check on what the fuel curve looks like, your brake specific (BS is measured in lbs of fuel per horsepower hour. Take the fuel flow in lbs/hour and divide by the horsepower at that rpm.) this number should be around .5 if it is around .2 or .3 then you are way to lean and this will make it back fire and no horse power.

I also agree that you need to check the distributor, just because it is new doesn't make it good.

Rex

 

OK i'll ask the question. what is this flatty going in.

 

Like the others say NEW Mallory can be alot of trouble, improper curve etc. Be glad to help or send you a lowner ( for shipping costs).
The other issue is a cam shaft not degreed properly off a bit. We done one for our salt truck that only made 75 hp , checked camshaft and gear was off a ton !!!!

 

Lots of good suggestions here, but my mind keeps going back to your comments that it seems to have a sort of misfire after rpms p*** mid range. This doesn't seem to me that it would come from restrictive ports or cam timing off. Maybe ignition, but I keep going back to those valve springs! I know you said they're new Isky that came with the cam, but did you check their tension before installation and also make certain of installed height being to spec.? The whole thing sounds like either ignition problems or valve float to me.
Dave

 

Bad cap? Get an MSD dizzy.

 

You should have 24° at 2000 rpm
Mallory ****s.......


I've worked on 6 french Flathead engines.
They had Stock ports that where anything from REALLY small to HUGE (that was a 239)

 

I agree, New Mallory ****s...

 

Hey paisano....

My new mallory was SO BAD, that even when retarding the timing heaps, just getting her off the line the engine would rattle badly even with Premium gas.

Get the distributor recurved for a FH....and i'll bet you'd be good to go. At least get it cheked out so you can either fix it, or eliminate it as the problem.

Should'nt be too hard to find someone in Italia/Milano who could do it for you.

Ciao amico...

Rat

 

Hello
following general advice, I have ordered a new Chevy modified distributor form Bubba. Will have to wait and then will do some more testing.
Thank you

 

I had a similar issue with my French Flathead
it was running too hot as the timing was too retard at high RPMs with the French dizzy, the valves got stuck, started misfiring

15 deg advance at 2,000 RPM sounds fine for a flattie though

 

My "NEW" mallory dual point was junk out of the box. Sent it to GMC Bubba and he fixed her up for me. Runs like a ****d ape now.
My other flathead has a Bubba Chevy conversion in it. I like that too.

 

This is the fellow you need to listen to. If there are indeed "experts" here on the HAMB, this man is one of them. If I had your engine and I had the problems you are running into, this fellow would be first on my "go to" list.

 

I would love to send the engine to HH , but shipping would be a nightmare....

 

Have you used a timing light to see what the advance curve looks like as you inrease the rpm? I'd be interested to know how much advance your getting at 2500 where you start having problems.

As well, seeing as you went to the trouble of putting a nice cam and set of heads on that baby, you are really wasting those performance parts as long as you are sticking with a points type distributor (dual points at that). I just put an msd on my flathead a few months ago, it's like night and day difference - it is one of the best and easiest things you could possibly do for your engine, and it may even solve your problems.

 

don't like electronics on an old style car or motor....seems a contraddiction to use an old engine with modern hi tech parts. but this is just my philosophy.....

 

When I was fooling around with these engines back in the 50's, if the electonics were available, I would have used them and I suspect everyone else would have used them. (and thrown their dual points away)

 

X2
Dave

 

If ya want run a hidden MSD box with your Mallory dist. I removed the secondary points on my Mallory dist and used the Primary points to trigger the MSD.

The points never wear out and the MSD provides all the spark you need.

Works like a charm on my bloen FH.

Just a thought.....you can look old school and have modern/hot spark.

Rat