Hot Weather, Fuel Injection & 383 Stroker

[my67c20]

Been searching the posts in the hopes of finding a solution to my problem. Problem is its too damn hot in Tucson to drive my truck 8 months out of the year. I have a C20, with a 383 stroker, mild cam, 1406 Edlebrock, TH350, 3:73 rear, dual exhaust with factory manifolds and Entropy Dual HPX Fans. First off, not a carb tuning expert, but do have a vacuum gauge and have adjusted the carb and timing. In cooler weather the thing is a beast, so I think my carb tuning is close. However, whenever I go someplace and try to restart it takes a bit to fire up, which is probably due to the fuel boiling since I do not have a spacer. My basis for too hot, is primarily based on the fact that the radiator fans run not too long after I am running and gauge sits about about 200. Also the temp sensor is on the drivers side head.

Recently been talking about selling it to get something more modern, since we have been talking about getting another camper. So the wife was quizzing me and asking what it would take to eliminate my current issue. I mentioned that with a fuel injection system there is better fuel management, so that might help. Being the supportive wife she is, she said do it. Personally, i feel this is a trap and will cost me more later.

Doing my research and have narrowed it down to the Proflo 4 systems, so the question is for those that have installed one, have you experienced a cooler running motor? Of course this question is not limited to just the ProFlo guys. Also looking for any other suggestions. Thanks

[RustyPile]

1406 Holley????? Pictures please...

[biketopia]

why not buy a 20 dollar spacer and see if that fixes your fuel issue? For a cruiser it's hard to beat the consistency of modern fuel injection. My brother has installed various aftermarket set ups working in a hot rod shop and hands down he says the best one has always been a holley sniper set up. under a grand and you don't have to mess with an intake change, and can always change out and upgrade or adapt later on. https://www.holley.com/products/fuel...arts/FR550-511

[1-PU70]

I live in FL and have fuel boiling problem myself with my 402 and a Q-jet. Mine is more of a hesitation after waiting for a long light. What im in the the process of doing now is electric fuel pump with return regulator. 3/8 in and 3/8 return. I hope this solves my problem. There is a lot of info on the internet about this.
Good luck

[Steeveedee]

What temperature thermostat are you running?

Is it a standard or high flow thermostat ?

Does it run hot sitting at lights or at speed?

How many rows does your radiator have?

To answer your question, the hard starting may go away, but I seriously doubt that it will run any cooler with fuel injection.

[my67c20]

I believe the thermostat to be a standard 180, only because when i bought it I never asked for anything special. The radiator is a 1967 - 1972 Chevy Truck Alum Rad - For SBC/BBC - 2-rows of 1" Tubes, Dual 11" HP fans, Alum- 4 Row Mounts-AUTO-trans. The temp does not change, based on gauge at idle or in traffic.

[SCOTI]

If you're having issues w/possibly cooking the fuel @ the carb/intake, the LAST thing I would do is any TBI style injection that has the ECU in the throttle body which is where your heat soak issue is. In simpler terms, avoid the Sniper or FITech type set-ups.

I like the Edelbrock Pro-Flo set-up. The buy-in price is pretty good considering you get an intake, throttle body, injectors, ignition, w/a remote mounted ECU & Bluetooth control capability. But, the caveat is refined tuning after that basic set-up is not readily available. Whether you need that tuning is a coin flip. It's easy to believe the logic of all you need to do is input the specifics & the computer uses pre-set mapping w/similar range of input data for your 'tune' & then the computer uses the data from the sensors to put things in range from there. It's not always that simple. If you have an issue & aren't good (knowledgeable) @ making the tweaks, you may not make it better; you could EASILY make it much worse.

Holley's higher end set-ups have similar features as the ProFlo-4 but initial purchase is ~1k higher. They also have aftermarket tuning support from tuners who do tuning for a living all across the country.

The after install/after driving tweaking is where you have to ask yourself the 'what's most important' question. I'm struggling w/this as well. The Edelbrock sure seems it would work well for me. But if it doesn't, I'm relying on some guy on the phone to help me vs. a tuner connecting into the logic & tuning w/his tools/experience from the data he reads.

[Steeveedee]

Originally Posted by my67c20

I believe the thermostat to be a standard 180, only because when i bought it I never asked for anything special. The radiator is a 1967 - 1972 Chevy Truck Alum Rad - For SBC/BBC - 2-rows of 1" Tubes, Dual 11" HP fans, Alum- 4 Row Mounts-AUTO-trans. The temp does not change, based on gauge at idle or in traffic.

Thanks for the answers! That set up should run cooler than that, imo. I forgot to ask, and don't see it above. Do you have AC and is it running when the engine gets this hot? 200 isn't bad if the AC is running.

I went through my cooling system and the thing that finally cured the problem (biggest effect) was to put in a high-flow thermostat.

I'm not an expert on strokers. I'm throwing this question out to those more knowledgeable than I. Do they require the heads from a 400? I think the 383 uses a 350 block, so maybe not? The 400 SBC heads and block are drilled for steam holes to aid in cooling. That I do know.

I'd add the heat insulating spacer. It helped the carburetor (E-brock 1406) I had on my Skylark. I had to seal it up with shellac, though as it leaked. Something to watch out for.

[tdangle]

I am also having the same type of problem, GM crate performance 350, Holley Carb. All new. Engine runs fine as far as temp goes, but restarting after sitting for 15-30 minutes a terrible bog in acceleration. Tried a 1/2" phenolic spacer with a little improvement. Especially bad when it's 100+ and am running A/C. Thinking EFI may fix things

[geezer#99]

Originally Posted by tdangle

I am also having the same type of problem, GM crate performance 350, Holley Carb. All new. Engine runs fine as far as temp goes, but restarting after sitting for 15-30 minutes a terrible bog in acceleration. Tried a 1/2" phenolic spacer with a little improvement. Especially bad when it's 100+ and am running A/C. Thinking EFI may fix things

Holley carbs need a heat plate instead.
Like this.


https://www.summitracing.com/parts/h...hoCwC4QAvD_BwE

I wonder if a lifter valley shield would help with keeping heat from off the intake underside.
Like this.

https://www.summitracing.com/parts/m...hoCoRoQAvD_BwE

[my67c20]

SCOTI, heard a lot of bad things about ECU's in throttle bodies especially since the under-hood temperatures on these trucks is horrible, which is why the Pro-Flo is more appealing for my application. Also the only other thing i would need to purchase would be the fuel sump system, unless I put in an electric pump. End of the day, I want to be able to enjoy the truck versus looking at in the driveway. It was my summertime toy when I lived in the midwest.

Steeveedee, no AC on this beast, although been thinking about adding that option at a later date. Thermostat's are cheap, but I do not see that solving the starting issue when warm, although toss in a spacer and see what that gets me. A stroker motor is a 350 block, clearanced for a 400 crank and rotating assembly. Also I have cast 64cc heads. Hate to do a complete top end kit cause at that point I might as well sell out to the LS swap.

[Andy4639]

I read through this thread and saw no mention of it so I will ask.

Does it have the HEI in it are the old points? If it has a HEI installed it could be the module issue. The cheaper HEI units bought off E bay and such use cheaper modules. The GM modules seem to work better and make sure you use the heat sink grease on them as well. It needs 12 volts at all times also just incase you didn't know.

Just for info:
I wouldn't do the Fuel injection until I got it running right. My 2 cents.

[SCOTI]

Originally Posted by my67c20

Been searching the posts in the hopes of finding a solution to my problem. Problem is its too damn hot in Tucson to drive my truck 8 months out of the year. I have a C20, with a 383 stroker, mild cam, 1406 Edlebrock, TH350, 3:73 rear, dual exhaust with factory manifolds and Entropy Dual HPX Fans. First off, not a carb tuning expert, but do have a vacuum gauge and have adjusted the carb and timing. In cooler weather the thing is a beast, so I think my carb tuning is close. However, whenever I go someplace and try to restart it takes a bit to fire up, which is probably due to the fuel boiling since I do not have a spacer. My basis for too hot, is primarily based on the fact that the radiator fans run not too long after I am running and gauge sits about about 200. Also the temp sensor is on the drivers side head.

Recently been talking about selling it to get something more modern, since we have been talking about getting another camper. So the wife was quizzing me and asking what it would take to eliminate my current issue. I mentioned that with a fuel injection system there is better fuel management, so that might help. Being the supportive wife she is, she said do it. Personally, i feel this is a trap and will cost me more later.

Doing my research and have narrowed it down to the Proflo 4 systems, so the question is for those that have installed one, have you experienced a cooler running motor? Of course this question is not limited to just the ProFlo guys. Also looking for any other suggestions. Thanks

I'll add that temp probes will read higher @ the cylinder head vs. @ the intake/radiator (within the cooling systems loop of flow). So, 200° @ the head is prob about right w/a 180° thermostat.

What I'm reading suggests that everything is great as long as the temps are cooler (temp outside in your area; not the trucks)? How close are the exhaust tubes to the starter? Can you put some sort of heat barrier between to see if there's a possible improvement? What is the base timing & timing @ full advance?

What I would do is make a list of the current concerns & try some of the simple tricks being suggested. Update the impact if any, on the list & we should be able to zero in especially as a group.

[P7M89MM]

Originally Posted by Andy4639

I read through this thread and saw no mention of it so I will ask.

Does it have the HEI in it are the old points? If it has a HEI installed it could be the module issue. The cheaper HEI units bought off E bay and such use cheaper modules. The GM modules seem to work better and make sure you use the heat sink grease on them as well. It needs 12 volts at all times also just incase you didn't know.

Just for info:
I wouldn't do the Fuel injection until I got it running right. My 2 cents.

I would agree with this. I’ve had similar issues with my zz502. Was starting fine but was getting hot weather, low throttle hesitation. Added a spacer, rerouted fuel lines, and went to hard fuel lines as well. This summer it just started shutting off randomly. Swapped out the distributor, module, and ignition and now no issues.

[my67c20]

geezer#99, that heat shield is ugly, can't do ugly, gotta be something sexier.

Andy4639, yes it does have HEI. Can't say its the top of the line, but does has battery voltage. What are your thoughts on tuning with an O2 sensor?

SCOTI, I could move the sensor higher and see. When I installed the new radiator, i did not want to redo my wiring, so I took the lazy route.

All great simple solutions that can be easily done on the cheap. This is why I love this forum.

[Steeveedee]

Originally Posted by my67c20

SCOTI, heard a lot of bad things about ECU's in throttle bodies especially since the under-hood temperatures on these trucks is horrible, which is why the Pro-Flo is more appealing for my application. Also the only other thing i would need to purchase would be the fuel sump system, unless I put in an electric pump. End of the day, I want to be able to enjoy the truck versus looking at in the driveway. It was my summertime toy when I lived in the midwest.

Steeveedee, no AC on this beast, although been thinking about adding that option at a later date. Thermostat's are cheap, but I do not see that solving the starting issue when warm, although toss in a spacer and see what that gets me. A stroker motor is a 350 block, clearanced for a 400 crank and rotating assembly. Also I have cast 64cc heads. Hate to do a complete top end kit cause at that point I might as well sell out to the LS swap.

I doubt it needs anything done, then, engine-wise.

[my67c20]

Need to make a correction. The fan switch is controlled by the temp probe in the drivers side head and the temperature gauge is plumbed into the passenger side head. Currently not using the dash gauge. So if I plan to juggle things around, should i plumb the gauge to the drivers side and the fan controller to the manifold? Or should i plumb both to a tee fitting of sorts to the manifold? Currently have an Edelbrock Performer Manifold. Thanks

[Andy4639]

Are you using the normal truck starter? How far is it from the exhaust?

I would look at getting a high torque starter and getting as much distance between the exhaust and starter as you can. Check this thread out. This was pre LS swap days.
As far as tunning with a 02 senor I would try and find a local tunner to take a look at it. Having another set of eyes looking at it may be just what you need.

http://67-72chevytrucks.com/vboard/s....php?p=4151565

[my67c20]

Andy4639, i don't have a starter issue, just a fuel boiling issue. I am the cool guy coming into the park lot, but nothing cool about cranking it over and waiting for it to fire.

Based on feedback, I think step one is to relocate the fan controller to the thermostat housing. I can leave the gauge connected to passenger head for now. I need to check the fan controller and see what the temp is that the fans come on and when they go off. From my research, I feel the thermostat should match the controllers fan on temperature, so I may be able to go to 160, possibly high flow. I still need to research the carb spacer plate. I feel like there is a better option versus that ugly flat plate.

[geezer#99]

That ‘ugly’ but highly functional plate is for a Holley.
Doesn’t work with your ‘ugly’ shiny Edelbrock.
Best material is a spacer made from wood.

[Andy4639]

Originally Posted by my67c20

Andy4639, i don't have a starter issue, just a fuel boiling issue. I am the cool guy coming into the park lot, but nothing cool about cranking it over and waiting for it to fire.

Based on feedback, I think step one is to relocate the fan controller to the thermostat housing. I can leave the gauge connected to passenger head for now. I need to check the fan controller and see what the temp is that the fans come on and when they go off. From my research, I feel the thermostat should match the controllers fan on temperature, so I may be able to go to 160, possibly high flow. I still need to research the carb spacer plate. I feel like there is a better option versus that ugly flat plate.

Just trying to cover all bases.
I would get a adjustable thermostat and use for the fans. Such as this. I have one of the cheaper ones in my 64 SS Impala and it works great. With the AC on it keeps the motor @ 190*.

https://derale.com/product-footer/el...s/16759-detail

[my67c20]

(long read) Reviving the dead. First off thanks to everyone for their suggestions. Over the early (cooler) months on the year I did add a spacer and moved the temperature sensor to the thermostat housing, plus replaced a few dried-out fuel lines. Fans run less often, but hot start issues still existed. Investigated adding a return line system to cycle the fuel, but never happened.

Fast forward a few months, needed to use the truck and the rear fuel bowl gasket was leaking, again This was the straw that broke my back, so I pulled the trigger on the Holley Sniper Master Kit (please don't hate me).

In process of this install, I knew I needed to add a return line. Since my current sending unit was reading incorrect, I figured now was a good time to replace it. I searched for one with a 3/8" output and return line. All I could find was the stock version with the 5/16" return. I know how to solder, why not buy 2 and modify one with 3/8” line for both? The result was something so pretty and it would give that stock appeal.

Problem was, it did not fit thru the opening in the tank. I probably could have spent more time on it, but the master kit came with a return fitting, so I just went that route. Maybe something to consider for the future.

The kit came with the fuel pump and filters, so next thing to tackle was where to mount it. Found a nice place on the frame, near the place where the fuel lines exited the cab. Spent some time bending up a nice bracket, drilling holes for the pump to mount and even slapped some paint on it. Unfortunately, when I went to position the bracket, it was too wide to fit between the rails. Fortunately, I was able to rotate it and have the fuel pump mounting holes line up.

With the fuel pump mounted, next step was to route fuel lines. Got me some 3/8” aluminum line from Summit and using my flaring tool, put a small bubble flare on the end to retain the line. With some creative bending and drilling another hole (with grommet) near the original cab exit I was able to route the lines out of the cab.

Since I was under the truck now was a good time to deal with the 02 sensor. I decided to mount it on the right side. The kit comes with the clamp on bung fitting, which is the route I decided to go. If I had my welder nearby, I would prefer to weld a bung in place. I marked the location, then unbolted the downtube from the stock manifold, so I could drill the hole. After wrestling with the exhaust and bolting it back in place, I installed the clamp on bung fitting. In hindsight, I should have positioned the fitting and secured the clamps, marked the hole, then dropped the exhaust. Tightening the clamps was difficult due to space constraints

Once the 02 fitting was installed and with the fuel system sorta done, next step was to tackle the extra wiring. Not an overly complicated task, but the kit wiring if untouched could look like a spaghetti fest and for me that was not gonna fly.

The throttle body has connections for 5 harnesses. One is the power harness, second is the fan / tach harness, third is the temperature sending unit harness, fourth is the 02 connection and the fifth is the controller connector.

The cable length provided in the kit for the temperature sending unit looks like it was intended to be installed someplace in the manifold. The only place I could do this was located right under the upper radiator hose. Had to add about 3 feet to the wires, so I could route it around the back to the port in the left side head. Would be nice if there was an option to buy a 3 foot extension.

The power harness has the fuel pump fuse, a relay, switched input and the coil connection. Trick was where to mount this and not make it look horrible. Had to cut off their harness wrap and redo it so it was to my standards. Probably could have left what they had, but again not how I wanted it to look. Once I figured out how to route the wires, it was a straightforward install.

The only wire I needed from the fan / tach harness was the one to connect to my aftermarket tach. This was removed off the distributor for the coil wire. Again, made it pretty and mounted it behind the engine.

The 02 connection was straight forward. For the controller, I would need to drill another hole in the firewall. Fortunately, when I switched from stick to auto, I still had the clutch linkage boot, so I just stuffed the wire thru there.

The master kit came with everything for a basic install, was easy to install with basic tools and probably took about 16 hours over a few weeks due to runs to the store for this or that. Still need to make the right connection to the fuel sending unit, but at least the gauge works.

After install and before starting there is a specific process for setup that must be followed, and the directions do a great job of walking you thru it. After reading reviews and watching videos, this was the point where I was expecting issues. I cautiously went thru the set-up process being sure to do exactly as instructed. All screens displayed as they should, fuel pump functioned, no fuel leaks, so now it was time to turn off the key and fire it up. Turned the key to the run position, waited a few seconds for the fuel pump, turned the key to the start position and it fired up right away, with a high idle. Waited for it to idle down, but it did not and heard a loud sucking noise as well. Of course, this was the point I realized I forgot to hook up the manifold vacuum line. Once that was hooked up, idle came down no leaks, time for a test drive.

The system learns when the coolant hits 160 degrees, so they recommend you drive it nice for a bit. Clearly, they don’t drive a classic vehicle. Anyways, hit the open road and talk about night and day difference. No hesitation coming off a stop, immediate throttle response and feels like there is some power gains, or it could be assumed from the dual marks left on the road. Stopped to fuel up (gauge works) while hot and it fired right up. Cold start next day (85 degrees), fired right up.

Overall, I could not be happier and wonder why I waited so long to pull the trigger. Still needs some tweaking and could use a tune-up, but what a difference is has made on the drivability. It still runs hot and had the temp climb up to 202, but it was 100 degrees and the throttle was getting pressed hard. When I just drove it while learning, it hit 195. Of course, not my first choice of vehicles to drive in these temperatures anyways, but nice to know I can. If you made it this far, thanks for reading and if you have questions let me know.

[my67c20]

More pictures

[body bolt]

I have the same problem with my '71 350/350, A/C, HD cooling, 190F thermostat, have an insulator on both the fuel pump and carburetor. The last thing to try before I go with Holley Sniper is a Carter P4070 fuel pump to push fuel through the mechanical pump. I have observed that running cool water over the mechanical pump causes it to run better.

[my67c20]

I did think about a return system and also thought about going to an electric pump, but when i had the reoccurring issue with leaking bowl gaskets, it was enough to push me over the edge. Had no issues in the midwest, but in this heat rubber and fuel do not stay stable.