Still getting poor mpg. Possible culprits?

[Daryl]

your fuel milage is crap due to stoking your engine

NOT what I wanted to hear, John!!

 

[Daryl]

Well crap, at this point I may as well throw a supercharger on it and throw everything to the wind!! LOL

 

[Snorky]

Well crap, at this point I may as well throw a supercharger on it and throw everything to the wind!! LOL

It'll be fine!

 

[ttocs]

yea unless you are driving it like a grandpa and never getting into it, that thing is made to burn fuel now. As mentioned tire pressure is a simple way but you are not going to be getting 20 mpg anymore.

 

[RAU03MACH]

 

[RAU03MACH]

 

[RAU03MACH]

any time you stroke an engine
problems will appear
i can name several
gas milage
overheating
constant timing adjustment
oil consumption
cant run the streets like normal
this is the reason why i dont stroke an engine
seems that you have experienced all of the above

 

[95opal]

Last time I threaded up on this I was at 14mpg. Since then, down to like 12mpg.
I’m not driving any differently, etc etc.
I cleaned the TB, MAF sensor and air filter. Probably unrelated, but also installed new thermostat, thermostat housing, water pump and radiator flush/fill.
Using same Chevron 89 pump gas and Techron additive/fuel system cleaner every 3k.
So what can I do? Where am I missing the boat?

As always, I appreciate and welcome any/all input.

i assume this is city mpg?
not uncommon to see low mpg considering you added more cubes and better flowing heads. Although 12 mpg seems a bit low for a 347.
did you check to see if you have a leaky injector? Could also be your ECT is out of limit or reading incorrect. Could also just be a rich tune. Whats the AFRs look like.

 

[Daryl]

any time you stroke an engine
problems will appear
i can name several
gas milage
overheating
constant timing adjustment
oil consumption
cant run the streets like normal
this is the reason why i dont stroke an engine
seems that you have experienced all of the above

Oil consumption has never been an issue. Overheating was borderline but definitely under control now. Not sure what you mean, John, by “can’t run the streets like normal”, can you explain please? Car performs well bopping around running errands, in town stuff, etc

 

[RAU03MACH]

lets run a 60mile Cruze around from place to place far a whole day
you will understand overheating and all that fun stuff im talking about

 

[RAU03MACH]

not just talking about getting items down street
over hear lots of poker runs from bar to bar and long-distance runs city to city

 

[RAU03MACH]

i assume this is city mpg?
not uncommon to see low mpg considering you added more cubes and better flowing heads. Although 12 mpg seems a bit low for a 347.
did you check to see if you have a leaky injector? Could also be your ECT is out of limit or reading incorrect. Could also just be a rich tune. Whats the AFRs look like.

its crazy i have seen many of stroker motors fail
some of the guys have sent out motors to have built and we go on poker runs
and those expensive engines cant hang
stroker engines belong on a track short runs and that is it
i have seen some stroker engine average 14 and hear in parts of Texas new Mexico thats it

 

[Daryl]

Bad news, but it is what it is. Definitely not what I was hoping to hear, but I guess I’ll just have to accept it and live with it. No sense in crying’ over spilt milk.

 

[RAU03MACH]

It happens
A lot of people don't think about all the things that come along when stroking an engine
They want to jump in both feet when they hear hp numbers
And dont relize notw the car has become a trailer queen for long distance or a garage car
I do try to talk people out of it
But everyone is titled to his opinion
But have seen some bad experiences with stroker engines
There are other ways to get hp and still drive the car hard
All day long and enjoy it

 

[RAU03MACH]

Any thoughts, comments or suggestions regarding:
1. the oil on one of the old plugs; and
2. the “mist” of smoke with the new wires upon initial start up?

Thanks everyone. Hope you all had Merry Christmas


This is one of your post Daryl
This is one of the problems you are experiencing with a stroker engine

 

[95opal]

its crazy i have seen many of stroker motors fail
some of the guys have sent out motors to have built and we go on poker runs
and those expensive engines cant hang
stroker engines belong on a track short runs and that is it
i have seen some stroker engine average 14 and hear in parts of Texas new Mexico thats it

Any thoughts, comments or suggestions regarding:
1. the oil on one of the old plugs; and
2. the “mist” of smoke with the new wires upon initial start up?

Thanks everyone. Hope you all had Merry Christmas


This is one of your post Daryl
This is one of the problems you are experiencing with a stroker engine

1 valve seal possibly
2 condensation

 

[shovel]

Are you still doing all this with the 1995 ECU? 'cause.. the first place I'd be looking is to run a modern EFI controller with widebands and speed density.

Unless your location requires you to make more pollution by using the stock EFI for some reason.

 

[Daryl]

Yeah, right! CA is all about smog, pollution, no rules or regulations, etc. I mean, everybody everywhere knows that. Bwhahahaha!

Yes, still the original ECU but the car has been tuned professionally. What are your suggestions given that tid bit of information?

 

[RAU03MACH]

Just for shits and grins
Look at the ECU the engine computer
You can take it out and look and see if there is a piggy back chip on one end of the computer
Should be the opposite end of plug
If that chip is in it it can be unplugged to stock pull it out

But now you would be dealing with engine and component
That would need to be changed

 

[Daryl]

I’ll check it out. Thx, John!