PSD

hi, trying to order belts for my 71 Cutlass Supreme 350, option is there for heavy duty cooling. belt is different part number.
how can I figure out if my car has normal or heavy cooling?
what is different? pulley diameter or thickness?

Fun71

You can measure to determine which belts you need.
Either measure the length of the actual belts (if you have them) or use some 1/4" or so rope (so it doesn't bottom out in the V grooves) around the pulleys to measure the length needed.

PSD

yep, i can take the old belts with me to the store to get replacements.
i was more curious about the heavy duty cooling and what it was, like an external trans cooler or thicker rad or different pulleys more water flow..

Koda

Heavy duty cooling was an option that was available by itself, or would come baked into some things like steep differentials or air conditioning. It typically was a larger core radiator (so in 71 probably a 4 core instead of a 3 core), a fan shroud (instead of none), and a 6 blade clutch fan (instead of direct 4 blade.) In 71 the water pump MAY have been different, I am not a 71 expert.

I would think belt length would be the different part number. Most water pumps varied by the length of the pump, as in how far out the pulleys extended and how many grooves there are. The pulleys on the clutch fan vs direct fan may be different.

RocketDevo

To elaborate on what Koda said, HD cooling could come in 3 or 4 core radiator versions. The main thing that had to change when you had HD cooling on non AC cars was the water pump pulley. IT is stamped with "KM". It was to account for the longer water pump shaft with only 2 grooves as opposed to the 3 groove AC pulley. The water pump for AC cars in 1971-72 was 407586, if you had HD cooling in those years but no AC the water pump was 408329. The "KM" pulley would allow the belts to line up.
Hope this helps.

joe_padavano

HD cooling would have used the smaller 6 1/8" water pump pulley. Standard cooling used the 7 5/16" pulley.

PSD

Very helpful, thanks guys.
i figured the pump pulley might be smaller to increase the speed. would need slightly shorter belt i suppose.
my car has shroud, 6 blade fan and 3 groove wp pulley.

now i need to sort the AC, comp is loose thanks to no rear bracket. looking at the aftermarket valve covers, I'm wondering if they had a clearance issue and didn't put the bracket back on.
at least they left it in the trunk of the car. actually 2 brackets, so I've got more research to do.

seems like just getting the right info and parts is more work than the wrenching..

joe_padavano

The real problem is correcting stupid stuff done by idiot previous owners...

Fun71

Check the head bolts to make sure the stud bolt is there for the lower part of the AC bracket. If the PO used ARP bolts, there may not be a stud in that position.

PSD

got some issues with the brakes, wheel cylinders leaking, flare nut fused to a line. 2 new cylinders and 1 brake line later, entire system is flushed of the gunk black brake fluid.
only problem now is the ratchet adjuster on the driver side doesn't sit up against the star nut, it's just hanging out. the top spring doesn't engage tight in the other piece either.
drum brakes are frustrating. I've had the rear wheels on/off at least 10 times now..

joe_padavano

Probably because you have them assembled incorrectly.

In this photo, you can see that the spring that goes above the self adjuster mechanism is installed incorrectly. The straight part of the spring must be above the star wheel. Since you incorrectly have the coiled part of the spring there, it is holding the adjuster arm out of position, which is why nothing lines up. DO NOT drive it like this. Take that apart and reassemble correctly.

PSD

ah, that makes sense. the other side is the same way. i did notice the springs were contacting and wondered what was going on, didn't consider they were backwards since the other side works fine.
no worries on that adjuster moving, it was frozen solid. I'm sure the PO drove it like that for years.
the star wheels are looking pretty worn, I may just get new hardware and will definitely fix those springs.
thanks for the help.

zeeke

Not to mention that star adjuster looks like it was put to a grinder. I'd replace that.

PSD

agreed, I found hardware kits at Advance Auto with new star wheels, just hoping they are halfway decent quality.

PSD

Got both sides done today, took about 2 hours. i will stick with what i said before, drum brakes are a pain. i don't have the best tools but thankful I did have the generic brake spring pliers to install the springs.
everything seems to be fitting together and working properly now.

olds 307 and 403

They sure are a PIA, stupid 4 wheel drum brakes. I could not believe that lines didn't twist when I changed the front wheel cylinders. I also found out I had front shoes when I went to do the rear brakes. I wondered why they were so tight on the backing plates, I figured it out when I checked the width. That kit looks decent.

joe_padavano

Sorry, but how are rusty brake line fittings (which can and DO happen with disk brakes) or incorrect parts that weren't verified by the installer prior to putting them on the fault of the drum brakes?

But hey, if you need an excuse to justify switching to disk brakes, knock yourselves out.

Koda

Drums stop suprisingly well. I really only have two issues with them. One, if it's a 4x4, and the drum is pressed onto the hub in that model car, you are into 4x4 locking hub bearings to work on the front brakes. It's like a colonoscopy, and a giant needle injection to the tookus at the same time. Second is brake fade when used hard or wet.

oldcutlass

I've used 4 wheel drum brakes for over forty years and never had issues with them. I know under certain conditions there may be issues and drive accordingly. They are extremely reliable and pretty simple to work on.

PSD

I had a 68 Mustang 6cyl with 4 wheel drums when I was a young man. Those brakes would not stop at all when wet. Also something wasn't right up front, as the car always pulled badly during quick stops. With no power assist they did require a heavy foot.

Funny thing was borrowing my friend's Cadillac back then, not sure which model, but it was a mid-80's with heavy power assist. First time i hit the brakes my face went into the steering wheel. took about 3 times doing that before i figured out I was slamming on the brakes

PSD

tried to start it today, would just crank. it cranked strong but never a hint of starting. I'm guessing spark.
so i look under the dash to find a birds nest of wires, some cut, some unplugged, twist taped together, wire nuts, etc. a real mess.
i just touched a few wires and now it work even crank. battery is fine.

it's a 71 350 engine, but looks like converted to HEI.

any ideas where i can find wiring diagrams?

oldcutlass

Here you go:
https://classicoldsmobile.com/forums...d-dfire25.html

PSD

much thanks.
is the HEI fairly simple? it appears to be, just one wire going to the top then some more going into the distributor.

oldcutlass

Yes, first check that you have voltage with the ign key in both the start and on positions. For your no crank issue, there is a neutral safety switch on the column, with 2 purple wires (disregard the others). See if you have 12v on both purple wires when you turn the ign key to start with the shifter in park or neutral.

joe_padavano

He said it cranks, there's no spark. The NSS is not the problem if it cranks.

Run a temporary wire from +12V directly to the BATT terminal on the HEI cap. Now see if you get spark. Note that if it starts, you will need to disconnect this wire to shut it off.

PSD

first it cranked, no start, then wouldn't crank after I checked under the dash..
not sure how, but I must have knocked the double purple wire off the NSS, because it was hanging loose.

so now it cranks again but no start.
ran a 12v wire from positive post on the battery to the HEI, still no start. not even a hint.
i can smell gas when cranking. don't think i pumped the pedal enough to foul the plugs though.

the coil inside the cap looks generic, but do they just outright fail? i would expect weak spark, misfiring, etc.
I guess I'll proceed to HEI troubleshooting.

Fun71

It would be more likely that the ignition module would fail instead of the coil.
Have you checked to ensure the firing order is right on the plug wires and the rotor is pointing to #1 terminal when the engine is at TDC on the compression stroke?

PSD

the car ran fine, parked for 3 days, now this.

one thing I noticed before but didn't fix yet, the button inside the cap is completely gone. I'm thinking there may be a pretty big air gap inside the cap that the spark has to jump.
wondering if that caused any damage..

I have new cap with button and rotor, will put those in tomorrow and see what happens.
will check for spark too.

oldcutlass

Missing button most definitely will keep it from starting.

joe_padavano

Did you actually verify that you have a spark at the plugs while cranking with this temporary power wire in place?

PSD

no, did not verify spark since attaching the 12v lead. pretty safe bet it isn't there though. .

funny thing is, i found the button was gone a few weeks ago but the car still started right up and idled fine without even a miss. plugs were gapped 0.080 too, so spark must have been hot.
something changed.

i'll start on it soon and report back.

PSD

just to start with, verified 12v at the feed to the HEI, voltmeter reads 12.55, then used a test light to draw a little current, looks good.
put in new cap/button/rotor, verified spark at #1 lead, jumped a gap over 0.08..

but still won't start.
verified firing order and wires on cap properly. HEI wire harnesses look old an crusty but it still works.

thing is, it doesn't even cough or sputter. nothing since it ran fine a few days ago.
baffling.

joe_padavano

Next step is to check timing. You can use a timing light even while cranking.

Koda

Just a silly question, but did you put the cap to coil wire on backwards when you went in there?

PSD

dist feels tight, i couldn't move it by hand.
i hope it's not a timing chain issue.

i'll have to educate myself on timing marks and most likely clean the balancer and mark with white paint.

PSD

i'm not following, you mean the little wires attached to the coil that ride in plastic slots in the cap with spade terminals at the ends?

what's bothering me is the car ran fine days ago, i didn't change anything, just tried to start it and nothing.

oldcutlass

#1 your plug gap is way too big, drop it down to .045. Are you sure the engine is not flooded? Wet spark plugs don't fire well.

PSD

well this is embarrassing..
on a whim I shot some starting fluid in the carb and it fired right up.
very strange since earlier i pumped the gas pedal and could smell gas while cranking, but it just wouldn't start, didn't even try.

so, is there a check valve in the pump or carb bowl that went bad?

BTW- never overlook evidence in your face- there was a can of starting fluid in the car when i got it, so this isn't the first time it happened.

PSD

Does this look right? for some reason I thought the fuel filter should be filled at least halfway. I don't even understand how it's getting to the carb, unless the air is pressurized in the filter and pushing just enough through..

https://www.youtube.com/watch?v=A8AJ...ature=youtu.be

Fun71

It's not uncommon for the filter to look empty while the engine is running. Since the engine is running, fuel is obviously getting into the carb.