April 06
Hi all,
Been travelling and then finally got a couple of oil leaks sorted out.
I have started to use the vehicle.
First test has shown a 14% increase in MPG from 14.8 to 16.9 (per USG)
This was achieved on a 153 mile circuit that was mostly freeway at 55-to 70 mph but did include 10+ miles of stop and go.
I've noticed that the engine is running a lot cooler, approx 160 degrees F
I'lll find out if there is a different thermostat I can try to raise the temperature back to 180-190 F
I also think it could stand a little more ignition advance.
But i'm pretty happy with a 14% increase.
Attached is an image of the rebuilt engine back in the truck
Trevor 
Nov. 05
Hi all,
I've just purchased a 1988 GMC Jimmy with a Chevy 350 V8 motor. I need such a large vehicle as my hobbies require the towing of large trailers.
Therefore I need to get the very best mile-per-gallon figure I can.
Currently with a stock engine, K&N air filter and 3" bore exhaust i'm getting 15 mpg per US gallon (not towing).
I'm currently sourcing a rebuilt set of heads specifically to deck and groove them per the thinking and specifications of Mr Singh.
I also intend to install a shift kit in the transmission to hold the vehicle in 4th gear (again not towing)
Other ideas are water injection and a Helix throttle body spacer (which I have but have not yet fitted).
I'll keep you posted on the progress.
If anyone else is working on a similar path with a Chevy 350 I'd be pleased to hear fronm you.
Regards,
Trevor Heath
Port Orchard, Washington USA
March '06
I finished up the project on Saturday.
The motor started first try and while the ignition timing may still be a little off, the motor is idling smoother and, at a higher RPM than before the grooving.
In my case the motor had 176,000 miles on it and had never been apart before.
We replaced the valve springs and valve seals in addition to a "valve job" in addition to milling the head .040" and cutting the grooves.
While I still have the use of another vehcle, I decided to service the transmission and add a transmission cooler as well so it will be another week before I start putting miles on the Jimmy.
I agree with you though that I too find this vehcle very useful except for the fuel mileage, my best was 14.8 mpg per USG. For the record the vehicle was getting 14.8 MPG (US GALLON) in stock trim except for a K&N air filter and a 3" exhaust from the cat to the tail pipe.
I'm hoping to get 20 mpg per USG.
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Just wanted to say hi!
Written by Ik on 2010-02-15 14:46:55
What is up everyone? My name is Jessica. I am from Slovakia. I am new to the forum and just wanted to say hi.. I hope I posted this in the right section on your forum... [url=http://somender-singh.com/?3d6d382db4cd0432befab27aa62]http://somender-singh.com/?3d6d382db4cd0432befab27aa62[/url], | 350 Mod Questions
Written by satre6 on 2008-12-26 09:08:49
Do you have pioctures opf the grooving? I couldn't get them to show up on my screen. I am very excited about this! |
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