Carburetor Help??!?!?!?!?!

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jkallen83

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hey yall,
got a carb question. My 1960 valiant has the 170 slant 6 engine with the carter single barrel carb.

i've read that changing to a 2 barrel would greatly improve performance. my car is slow, 50 to 55mph puts me running from 2500-2800 rpms. i try to stay under 3000rpms to be safe since im not sure what is "safe".

question is, my carb works fine, BUT, on hills or the need to push around a tractor in the road lol, i have the pedal to the floor to get up the hill, would a 2 barrel carb help with this, and how do i know what carbs will fit???? just need a little more punch when i hit the gas pedal.
also from what i been seeing during my searching, there is regular carbs and also "super six" carbs, is there a difference in these?? im just not sure what will and wont work.

any suggestions???
 
There is no reason to maintain engine speed below 3000 rpm to be "safe".

There are lots of areas on the early slant-6 engines like yours that were very conservatively specified and leave lots of room for improvement. The exhaust is tiny and restrictive. The camshaft is much milder than it needed to be. The ignition advance curves are likewise very timid. But before you go modifying anything, make sure what you have is in tip-top tune and proper repair. Warm up the engine, remove all six spark plugs, block the throttle open and do a compression check; post the results. Make sure the timing mark accurately indicates TDC; the mark tends to slip over the years and then you can't tune accurately. You'll find tune-up parts and technique suggestions in this thread. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. Remember this engine will need periodic valve adjustment, too.

Once you've got everything correctly tuned and adjusted -- get the three books described in this thread and read 'em! -- if you're still unsatisfied with how the car runs, then it's time to look at modifications. There is no 2bbl carb that will be a direct bolt-on swap. You will need to install a 2bbl intake manifold as well. Complicating matters is your '60 Valiant's rod-type throttle linkage. The cleanest way forward when working with a '66 or earlier car with the rotating-rod throttle linkage is to modify a stock intake manifold to accept a 2bbl carb and alter the linkage to suit. See the parallel 2bbl setup article. Photo documentation of a very well done such conversion is here. Don't be tempted by the 1bbl-to-2bbl adaptors that show up from time to time on eBay and elsewhere; they cause more problems than they solve -- and remember, it doesn't matter if you're pouring peanuts out of a 5-pound bag or a 10-pound bag if the hole you're pouring them through is the same size (that is, the "adaptor" doesn't change the size of the hole in the intake manifold).
 
Thanks Dan, u always know ur stuff ... so what is a safe or max rpm before it begins to be damaging .or unsafe? Like I said, I stay under 3000, but don't go over just to protect the engine until I know what is safe.
 
There is no real "safe" RPM limit until you know the condition of the engine. How many miles are on it? What's been done to it internally through the years? Was it ever balanced? A stock 6 in good condition can see 5000 RPM easy. With perfomance upgrades they can see over 7000. If yours doesn't smoke or make any distrurbing noises, I'd start with an oil pressure test at normal operating temp.....then a valve adjustment and compression test if the oil pressure is fine. If it all tests good, move on to the full tune-up phase and get that thing moving!
 
Remember, the stock '60 Valiant setup was a 3.55:1 rear axle and a 23.7" tire diameter, which meant the 170 engine was turning 3021 revs per mile in 3rd gear with a manual transmission, about 3500 revs per mile in 3rd gear with an automatic. Split the difference for purposes of this conversation and call it 3300 revs/mile.

That's 3300 rpm @ 60 mph, 3850 rpm @ 70 mph, and 4400 rpm @ 80 mph (remember also, many Western states had no daytime speed limit on the interstates back then).

The 170 is happy to rev. It's just prevented from doing so by small intake and exhaust systems and a tiny camshaft in the stock '60 installation.
 
ok, the 1960 valiant had 41,000 ORIGINAL miles on it when i got it, and its just rolled over to 48000 miles for me. nothing has been done to the engine, it looks old and needs painted if i ever did have it apart, but other than that its stock best i can tell other than i had to put a new water pump. engine dont smoke, no noises other than the valve chatter.

dan, 3300 miles would probably put me in the neighborhood of 60mph. question is, am i "safe" to do that. especially when ur talking 70mph, thats ALOT of rpms, but is it still safe or am i shortening the life of the engine?

ive never hit the 3300rpm mark, highest ive hit was just for a minute and it was 3000 rpm running around 58mph. if i could "safely" run 60mph i would be HAPPY.

i just want to be "safe" but also at least keep up with traffic lol.
 
Traffic moved along faster in 1960 than it does now. You are perfectly safe to go ahead and drive the car. Tune it up properly as linked above, then consider modifications if you still want to.
 
jkallen83 said:
ok, the 1960 valiant had 41,000 ORIGINAL miles on it when i got it, and its just rolled over to 48000 miles for me. nothing has been done to the engine, it looks old and needs painted if i ever did have it apart, but other than that its stock best i can tell other than i had to put a new water pump. engine dont smoke, no noises other than the valve chatter.

dan, 3300 miles would probably put me in the neighborhood of 60mph. question is, am i "safe" to do that. especially when ur talking 70mph, thats ALOT of rpms, but is it still safe or am i shortening the life of the engine?

ive never hit the 3300rpm mark, highest ive hit was just for a minute and it was 3000 rpm running around 58mph. if i could "safely" run 60mph i would be HAPPY.

i just want to be "safe" but also at least keep up with traffic lol.
Click to expand...
As long as the oil pressure is good and it's properly adjusted and tuned, wind it up! Anytime you run the engine, it's shortening it's life. If you're concerned about it's crusing RPM, get a rear axle assy with a freeway gear in it but that will make your "get up and go" even worse.
 
3k rpm is nothing.....

1965 Honda 6 cyl.


IWISH.jpg
 
ok,
i hit 60mph today running at about 3100rpm, car ran GREAT. still need the power when i hit the hills, gotta work that out
 
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