Engine: Golden Hawk not running well

[5brown1]

I just purchased a 57 golden hawk that had been restored a few years back and had only 2250 miles after the rebuild. It did not idle well so I added a cleaner to the fuel believing the carb probably needed cleaning. I then drove about 180 miles and found no improvement. It was idling at about 1000 rpm and if put in gear drop to around 400 and act like it was going to quit with very rough idling. Reading through the PO receipts it appears that during the engine rebuild an R1 cam was installed. Anyway today I hooked up a vacuum gauge which read 14 on the scale which indicates extreme late ignition. I then got out the timing light and found the timing was way off. I got the timing set, lining the pointer with the correct line on the damper and the engine now sounds better but the vacuum gauge is still reading about 14 and the idle which I did not adjust is at 900 but drops way down and still acts like it is nearly stalling when put in gear. If I run it up to 2000 RPM it seems to run good.
Could the vacuum reading be caused by the cam? Could the valve timing be off and how does one check that - I almost don't want to ask. Why would the rpm drop so much?
Engine was rebuilt by a Studebaker man. Super charger was rebuilt as well as transmission (auto).

[FleetMaster68]

Have you checked valve lash, to tight can allow slight seat leakage, rough idle and low vacuum.

[SN-60]

'FleetMaster68's valve lash idea is a good one!.....If that doesn't help, I'd 'bite the bullet' and go through the carb, giving it a complete and thorough cleaning.....then I'd add an in-line fuel filter ahead of it......Good luck!

[karterfred88]

It sounds like you need to do a thorough tune up, including valve adjustment, fuel line cleaning and inspection for dirt, rust and dried fuel deposits in the float bowls. May need to overhaul the carb since fuel, or remnants of fuel may have clogged jets. Also with the idle so high and dropping so much, I would look for a massive vacuum leak, perhaps, if it has power brakes, the line leading to the booster assembly or the booster's internal diaphragm, may have dried out and split allowing a vacuum loss. Or another hose that may have fallen off, or cracked due to age. Although not an expert, my R2 Avanti, will easily idle at 650RPM in or out of gear, and show 15 inches of vacuum or more when everything is exactly right.

[PackardV8]

Also with the idle so high and dropping so much, I would look for a massive vacuum leak,

Also, check for leaks around the intake-manifold-to-head gasket area. If the steel shim gaskets were used, they have been known to rust out. This causes a permanent vacuum leak.

jack vines

[5brown1]

Just got done checking vacuum lines - there are only 4 and they are fine and nearly new. I torqued the intake bolts and adjusted the idle circuit screws with no change in the
vacuum. I then sprayed starter fluid around the 4 intakes and the engine bogged down on three of them. I repeated it three times with the same results. I assume that that tells me they are leaking. I did expect the engine to speed up if a leak were present.
It does have the composite intake gaskets now.

[PackardV8]

I sprayed starter fluid around the 4 intakes and the engine bogged down on three of them. I repeated it three times with the same results. I assume that that tells me they are leaking. I did expect the engine to speed up if a leak were present.
It does have the composite intake gaskets now.

Boom, there's the answer. One possibility is the heads and/or block have been milled enough the intake no longer seals properly. One way is to remove the intake, clean both surfaces with a file and then use Prussian blue spray layout dye on both. Rub them together and see where the blue is scratched off each.

It's possible the solution might be to use the steel shim gaskets, as they are thinner and would somewhat compensate for the milling.

Only expert examination will determine how to seal the intake to the heads.

jack vines

[5brown1]

Jack,
These were NOS heads and put on when the engine was overhauled. I don't know if any milling was done.
Also the individual who overhauled the engine removed the oil filter and told the owner it did no good anyway. I'm not comfortable with that. Your thoughts?
I have all the receipts for the mechanical work done and I'll check to see if it mentions work on the heads or block.
I did not find any evidence of work done to the heads. Just boring and cleaning the block.

[plym_46]

A performance cam can have the effect of lowering vacuum at idle, is the reading steady or is the needle bouncing around? 14 inches seems low for a street cam, I would expect 14 to 16 for a full competition grind, I would think you should be in the 17 to 19 range for a mild grind. Have you done a compression test? Incorrectly set valves could not be sealing completely leading to a loss of compression which will also lower vacuum. Were the head bolts ever re torqued after the rebuild?

Are the throttle butterflies closed at idle or are they hanging open? If you are not entering the idle circuit then your idle mixture will be lean, the lean mix could account for the big bog when selecting a gear from park or neutral.

I would suggest you set the timing using the vacuum gauge. get the idle as close to factory spec as possible, then rotate the distributor to a position which yields the highest steady vacuum reading. then tighten the dist lock down till snug. readjust the idle speed if necessary. This type of timing setting will usually be a little bit advanced and might give you some ping or spark knock under acceleration of climbing hills, if this is the case then turn the dist to retard the setting (that's why you left it snugged not tightend) till the knock disappears. This will give you the best timing situation for your actual engine conditions, fuel quality, operating temp, and the way you drive. Finally readjust idle rpm as necessary after the timing is set, and the dist tightened down.

[PackardV8]

Also the individual who overhauled the engine removed the oil filter and told the owner it did no good anyway. I'm not comfortable with that. Your thoughts?

You're right and he's wrong. The OEM by-pass filter does good work and is definitely preferable to not having anything on there.

jack vines

[karterfred88]

Since the intake gaskets are composite, gently removing the manifold should leave an imprint on the gasket, if they weren't glued to the intake first. That may show you where either the lack of clamping force exists or give you a clue to what is going on, such as a good imprint along the bottom of the port area or along the top only, or good at the front bad at the rear. If you can get a good photo of them, still in place on the heads and post it, the experts here can help determine what's wrong and suggest a fix, better than guessing.
Also,as you have probably surmised, because someone says NOS heads were installed, that doesn't mean they were any good or that they were in fact new or not rusty on the mating surfaces, requiring a cleanup milling-which could have been improperly done. It's also possible the intake itself is warped for some reason, the clamps compromised, wrong length bolts bottoming out, the Studebaker method of intake attachment is not one providing a lot of equalized clamping around the port.

[Alan]

On the oil filter, I prefer Franz. Polished stainless can and 50 cent filters that are much better than pleated paper types.

[5brown1]

Removed the intake and cleaned it up with a file. That works great Jack. The intake gaskets were brittle and broke when I removed the intake. I am going to use Dykem or something similar to check the fit.
I also discovered that the individual who removed the oil filter left the holes in the compression chamber open, duh. I also need a restricting fitting which fits on the head for the oil filter. Anyone have a spare to sell? I also plan to rebuild the carb while it is off - any tips from those with experience on this particular carb?

[doofus]

When doing the carb you will need a special wrench to remove the jet's. Speedway motors carries them,look in the flathead V8 section. Luck , Doofus

[5brown1]

Thanks, I found it - #910-81106
I set the intake on the block and it rocked because the exhaust runner touches before the intake runners on the drivers side. I don't have a real straight edge but used a 12" rule from an adjustable square. I believe that the passenger side is ok. However, it has a tube for the choke pipe extending from the compression chamber into the block which will prevent any work on that side. I have yet to find a way to remove that. I PMed a guy who asked about removing it from his manifold but have not received a reply.
Suggestions?