66 c10 engine upgrades

[Chevy nutcase]

My 66 c10 with its bone stock 250 runs fine but I think I can get more out of it. One thing I'd like to upgrade is the points ignition. I was wondering if a pertronix kit to replace my distributors guts is a good option or if just switching to a modern HEI distributor is the preferred method. Another component in question is the carb. Again it works fine but takes forever to warm up so I was considering a new carb and offy intake but again this is foreign territory to me as for what cfm the motor can handle. Love to hear your opinions on the matter

[61hawk]

I put a Petronix system in my '61 Studebaker Hawk when it was restored. The friend of mine who owns a restoration business puts them in all restorations unless the owners tells him not to. He has not had one unit go bad out of probably close to 100 vehicles. I'm putting a 331 Hemi in my '65 C10, I'm going HEI, but that's because I needed a new distributor, had I used the original I would have gone Petronix.

[Arne]

Nothing wrong with a Pertronix for reduced maintenance, but don't expect a noticeable performance boost. There can be some small improvements, like quicker starting and such, but the results can be lessened if your distributor isn't good. Worn shaft bushings are still worn shaft bushings, and the Pertronix dwell and timing will bounce around just as badly as the points ignition. So if your distributor isn't really nice, I'd go HEI.

[AcampoDave]

I copied this from some old Motortrend article. Maybe it will help you

To arrive at the most appropriate carburetor choice, there's a basic formula: engine displacement multiplied by maximum rpm divided by 3,456. For example: a typical 355ci small-block—a 0.030-over rebuild—with a 6,000-rpm max engine speed would work well with a 616-cfm carb ((355 x 6,000) 3,456 = 616.32).Jan 29, 2016

[Steeveedee]

Originally Posted by Chevy nutcase

My 66 c10 with its bone stock 250 runs fine but I think I can get more out of it. One thing I'd like to upgrade is the points ignition. I was wondering if a pertronix kit to replace my distributors guts is a good option or if just switching to a modern HEI distributor is the preferred method. Another component in question is the carb. Again it works fine but takes forever to warm up so I was considering a new carb and offy intake but again this is foreign territory to me as for what cfm the motor can handle. Love to hear your opinions on the matter

I used Standard Ignition's Blue Streak ignition products on my vehicles back in the day, and have gotten as many as 30k miles on a tune-up on a six cylinder. That said, I have an HEI in my big-block truck, but that's really only because I had an HEI available from another vehicle. What does your truck have in the way of emissions equipment? If you had a thermostatic air cleaner (for example) like was offered on some vehicles (possibly not your year) it might warm up and open the the choke sooner, a sure mileage improver. Give us some pics of your setup, and let's see what we can do to help.

[theastronaut]

Oem HEI would be the best option for ignition.

Remove the stock mechanical fan and swap to an electric fan and shroud, I just did this on my '66 with a 250 and it made quite a noticeable difference in power and it's quieter.

The stock intake/carb is probably the biggest restriction, along with the mild cam specs.


There are parts/mods out there to make 300 hp out of a 250, just depends on how much you want to spend.

[Chevy nutcase]

Originally Posted by Steeveedee

I used Standard Ignition's Blue Streak ignition products on my vehicles back in the day, and have gotten as many as 30k miles on a tune-up on a six cylinder. That said, I have an HEI in my big-block truck, but that's really only because I had an HEI available from another vehicle. What does your truck have in the way of emissions equipment? If you had a thermostatic air cleaner (for example) like was offered on some vehicles (possibly not your year) it might warm up and open the the choke sooner, a sure mileage improver. Give us some pics of your setup, and let's see what we can do to help.

I dont have any emissions on my truck and the air cleaner is just a can to hold the element. I'll get some pics tho thanks

[Chevy nutcase]

Originally Posted by theastronaut

Oem HEI would be the best option for ignition.

Remove the stock mechanical fan and swap to an electric fan and shroud, I just did this on my '66 with a 250 and it made quite a noticeable difference in power and it's quieter.

The stock intake/carb is probably the biggest restriction, along with the mild cam specs.


There are parts/mods out there to make 300 hp out of a 250, just depends on how much you want to spend.

The fan was also a point of interest for me so its interesting you brought it up and yes it's the predominant sound while driving. I'm not against electric fans but would a clutch fan be an option? I'll definitely do something with the intake and carb but I'm not looking to spend a fortune right now as I've just got my lowering kit and 4 new wheels and tires lol

[MT65]

Clutch fan is cheapest way in and can definitely do the job, elm is good also, try and find a Lincoln mark 8(?) at a salvage yard, pulls lots of air, also pulls lots of amps which all good electrical fans do.Maybe have to upgrade your alternator to a 100amp minimum, then larger charging wire from alternator to battery,10 ga not sufficient any longer….bottom line its all very doable, just how far do you want to go….

[theastronaut]

A fan/shroud from a HHR is really simple to fit to a C10. I had to slightly trim the flanges down for more water pump pulley clearance since the inline six is longer than the V8 shown on the website.

http://www.66c10.com/electric-fan/

[curvedglass]

I bought an HEI for my 230 off ebay a few years back. Rock solid. I have even done a tune up since. Easy to get a new cap / rotor / and plugs. I also have the 2 barrel weber with an adapter for the one barrel intake. A Header is in the wings. I also bumped the timing up a few degrees - just under the need for premium fuel. Langdons had the carb and adapter but he sold everything to the 6=8 folks. Don't have their link at the moment.

[Chevy nutcase]

This is the bone stock setup I've got right now and yea I just noticed my carb is weeping a bit. Yay

[AcampoDave]

I watched an Engine Masters where they tested mechanical fans. Some of them are huge horsepower parasites.

[Chevy nutcase]

Originally Posted by AcampoDave

I watched an Engine Masters where they tested mechanical fans. Some of them are huge horsepower parasites.

Yea that might be my next project. Electric or clutch fans would be a vast improvement

[AcampoDave]

Does your exhaust manifold still have that flapper deal with the thermal spring in the outlet? I've seen a few of those get stuck in a partially open position.

[Chevy nutcase]

Originally Posted by AcampoDave

Does your exhaust manifold still have that flapper deal with the thermal spring in the outlet? I've seen a few of those get stuck in a partially open position.

There is a flat coil spring on the exhaust manifold, under the intake where I've indicated. I don't think the spring is hooked up correctly or whatever it's supposed to control rusted away. Is this used to heat the intake and carb incoming gasses?

[gmtech68]

The heat riser valve is controlled by a bi-metallic spring like an old school home thermostat. When cold it directs exhaust up under the carburetor to assist in keeping the mixture from condensing. As the engine warms up it opens and blocks exhaust from directly blowing on the bottom of the intake. The springs do corrode, the bushings and shafts wear, and it is possible for the butterfly to break free of the shaft and sit wherever it likes.

[Chevy nutcase]

Originally Posted by gmtech68

The heat riser valve is controlled by a bi-metallic spring like an old school home thermostat. When cold it directs exhaust up under the carburetor to assist in keeping the mixture from condensing. As the engine warms up it opens and blocks exhaust from directly blowing on the bottom of the intake. The springs do corrode, the bushings and shafts wear, and it is possible for the butterfly to break free of the shaft and sit wherever it likes.

I'm pretty sure mine is days away from getting ejected from the tailpipe. Whenever I start the truck there is an awful rattle for the first 30 seconds that sounds like a putty knife in a fan.

[Short 3/4]

Have had very mixed results with the Pertronix kits. Have had one in my wife’s DD 65 Mustang for a couple decades with absolutely no problems. But had absolutely no luck trying to run one in a 65 Triumph TR4. They would fail at the worst possible times. Company would always immediately send a replacement under warranty, but could never tell me why they were failing. I finally went back to Standard brand Blue Streak points as stated above, and have never had another problem in years, go figure.
As far as my 65 Chevy, I’ve been running an HEI I bought from Langdons may years ago. Has been totally trouble free and tune up parts available anywhere. One of the best mods I’ve ever done to this truck.
For the exhaust manifold, you might want to look into a ‘big truck’ 292 3 bolt manifold. Found a repo on eBay a couple years ago that I’m really happy with. And they don’t have that stupid spring and flapper that never seems to work.
Hope this helps
Good luck with the truck
Tom

[Arne]

Originally Posted by theastronaut

A fan/shroud from a HHR is really simple to fit to a C10. I had to slightly trim the flanges down for more water pump pulley clearance since the inline six is longer than the V8 shown on the website.

http://www.66c10.com/electric-fan/

I'm looking at one of these too. Pretty affordable.

eBay link

[Chevy nutcase]

I'm seriously considering a major upgrade in the way of offy intake and edelbrock carb. I'd like a Clifford intake but those are much harder to find. I've got a pretty good idea what I'm in for but I always like to hear knowledgeable input before I drop another $1000. What would be the cfm range for my motor to reap the most benefits?

[AcampoDave]

The smallest Eddy carb is a 500 cfm. They are jetted rich and in my opinion are too big for a 230.
Edit: sorry I thought you had a 230 but it's still big for a stock 250. I'm a small block v8 guy but have read that many inliner guys use small Holly's. Have you checked their webiste? Personally, I'd tune that 6 up right with an HEI, then get the timing and the advance curve nailed down, add a sweet clutch fan and drive it.

[Chevy nutcase]

Originally Posted by AcampoDave

The smallest Eddy carb is a 500 cfm. They are jetted rich and in my opinion are too big for a 230.
Edit: sorry I thought you had a 230 but it's still big for a stock 250. I'm a small block v8 guy but have read that many inliner guys use small Holly's. Have you checked their webiste? Personally, I'd tune that 6 up right with an HEI, then get the timing and the advance curve nailed down, add a sweet clutch fan and drive it.

Do you think an HEI will alleviate some of my start up issues? It actually starts really well but if I don't let it warm up for a solid 2 minutes and do anything beyond grazing the throttle it falls flat until I let off the throttle. This doesn't go away until it's at operating temp a mile or so down the road.

[AcampoDave]

That may have something to do with that flapper gizmo on the exhaust being messed up. It could be a poorly functioning choke, a carb needing a rebuild, maybe a vacum leak, and yes, in part perhaps a worn out distributor.
But remember that it is fairly normal for a carburated engine to need a warm up period in cold weather. Especially when the carb is hanging off the side of the motor. Dropping another thousand bucks on it, as you said, may only wind up in disappointment and I've seen it many times when big ideas don't pay off and another basket case project gets sold on Craigslist. (Been there, done that)

Starting with the basics, a good tune, a distributor and ignition system that is verified to be fully functional and making sure your stock carb and its related components are up to snuff would go a long way toward buying the time to research any future engine mods more thoroughly

[Chevy nutcase]

Originally Posted by AcampoDave

That may have something to do with that flapper gizmo on the exhaust being messed up. It could be a poorly functioning choke, a carb needing a rebuild, maybe a vacum leak, and yes, in part perhaps a worn out distributor.
But remember that it is fairly normal for a carburated engine to need a warm up period in cold weather. Especially when the carb is hanging off the side of the motor. Dropping another thousand bucks on it, as you said, may only wind up in disappointment and I've seen it many times when big ideas don't pay off and another basket case project gets sold on Craigslist. (Been there, done that)

Starting with the basics, a good tune, a distributor and ignition system that is verified to be fully functional and making sure your stock carb and its related components are up to snuff would go a long way toward buying the time to research any future engine mods more thoroughly

I've owned carb cars before, this is the oldest but maybe its lengthy warm up procedure is normal. The choke is manual and that exhaust flapper looks like the only fix would be a new manifold. I do like your reasoning starting with a new distributor which is a cheaper and easier route. Maybe a summit distributor would suffice where an MSD would be overkill. A good carb clean and rebuild would also be fairly easy. I just need to figure out which one I have.