Inline 6 performance Pictures and info.

[brawley]

I know I could just swap out the inline 6 that came with my truck with a V8...but don't want too, trying something diffrent. What I have to work with is a rebuilt inline 6 250, with a Comp. cam, HEI dist., Hedman Headers.. looking for intake and carb set up with these componets..like the idea of dual carbs, but also looking at Holley 390, Edlebrok 500, or i've seen a Redline webber conversion, that might work. Also looked at Clifford and Offenhauser intakes. curious about intake heat?? as well.. what have you had success with..any pictures and advise would be nice..thanks

[geezer#99]

Have you cruised thru here?
http://67-72chevytrucks.com/vboard/s...d.php?t=276823

[diceman50]

I have done several fuel injection conversions over the last 20+ years two of which have been inline 6's. One of them is my current daily driver "HANK" a 1958 Apache with the original 235 engine.

It is a custom one off system consisting of:

vintage Edmunds dual carb manifold

dual Stromberg look alike throttle bodies

GM computer

GM and Ford sensors and ignition system.

I did a build thread on the Stovebolt forum if you are interested.

http://www.stovebolt.com/ubbthreads/...=988472&page=1

The other inline I did was for a friend of mine on a 261 in a 1950 3/4 ton pickup. On it I used a Clifford 4 barrel manifold and a MSD Atomic self tuning FI system. Don't fall for the no return fuel line needed claim. When you read the instructions you will find out that it only works if some very difficult criteria are met. In retrospect I would use the FAST self tuning system instead. I have done two of the FAST systems in the past although not on inlines.

I can tell you that the inline engine is a different animal when it comes to tuning the fuel maps. Also manifold heat is very important on an inline engine. Especially with an aluminum manifold hanging out in the wind. Also, The Clifford manifold I got had 2 small leaks between the hot water jacket and the plenum. If you use one you might want to pressure test it. I sealed mine with JB Weld.

[TJ's Chevy]

Originally Posted by diceman50

I have done several fuel injection conversions over the last 20+ years two of which have been inline 6's. One of them is my current daily driver "HANK" a 1958 Apache with the original 235 engine.

It is a custom one off system consisting of:

vintage Edmunds dual carb manifold

dual Stromberg look alike throttle bodies

GM computer

GM and Ford sensors and ignition system.

I did a build thread on the Stovebolt forum if you are interested.

http://www.stovebolt.com/ubbthreads/...=988472&page=1

The other inline I did was for a friend of mine on a 261 in a 1950 3/4 ton pickup. On it I used a Clifford 4 barrel manifold and a MSD Atomic self tuning FI system. Don't fall for the no return fuel line needed claim. When you read the instructions you will find out that it only works if some very difficult criteria are met. In retrospect I would use the FAST self tuning system instead. I have done two of the FAST systems in the past although not on inlines.

I can tell you that the inline engine is a different animal when it comes to tuning the fuel maps. Also manifold heat is very important on an inline engine. Especially with an aluminum manifold hanging out in the wind. Also, The Clifford manifold I got had 2 small leaks between the hot water jacket and the plenum. If you use one you might want to pressure test it. I sealed mine with JB Weld.

Attachment 1195290

Diceman50,
How well does the new MSD fuel injection system work on that motor? Looks sweet!

[diceman50]

It took a lot of trial and error and fiddling around to get it to work but, eventually I got it to running well. I can tell you that you shouldn't expect much help from MSD's tech support. They were very willing to help but have little experience with inline engines. In fact they told me that I was the first one to try it as far as they knew.

The engine would start and stall several times before it would idle. (3-4 or sometimes 6-8 times) When it did idle it would stall again if you revved the engine. It drove OK if you could ever get it to idle but would stall almost every time you stopped. I wore the tech guys out at MSD and to their credit they tried very hard to help me even exchanging several parts including the throttle body itself which contains the computer. Nothing helped so I concluded that the problem was with the software.

The breakthrough came when I rebooted the computer for the 100th time or more. When you reboot the system it defaults to a 350 V8 engine. You have to reconfigure the computer to your engine size, # of cylinders, etc. On this particular reboot I forgot to do that. It started and idled better than it ever had. When I figured out what I had done I changed the tune from 8 cylinders to 6 but, I left the engine size at 350. Huge improvement. I then started experimenting with different engine sizes and finally used 360 cu. in. I also increased the pump shot by 15% and the VE enrich by 10%. This made the engine very happy and it starts and drives well.

I don't know if there is a problem with MSD's software or if there is an inherent difference in the fuel curve between V8 and inline 6 engines. I tend to believe it is the latter because on my 235 we started with a VE table for a V8 engine and ended up adding a lot of fuel to it. It would be interesting to do a similar engine with the FAST system and see if it suffered the same problems.

This is probably way more info than you wanted, but maybe someone will find it helpful.

[TJ's Chevy]

Originally Posted by diceman50

It took a lot of trial and error and fiddling around to get it to work but, eventually I got it to running well. I can tell you that you shouldn't expect much help from MSD's tech support. They were very willing to help but have little experience with inline engines. In fact they told me that I was the first one to try it as far as they knew.

The engine would start and stall several times before it would idle. (3-4 or sometimes 6-8 times) When it did idle it would stall again if you revved the engine. It drove OK if you could ever get it to idle but would stall almost every time you stopped. I wore the tech guys out at MSD and to their credit they tried very hard to help me even exchanging several parts including the throttle body itself which contains the computer. Nothing helped so I concluded that the problem was with the software.

The breakthrough came when I rebooted the computer for the 100th time or more. When you reboot the system it defaults to a 350 V8 engine. You have to reconfigure the computer to your engine size, # of cylinders, etc. On this particular reboot I forgot to do that. It started and idled better than it ever had. When I figured out what I had done I changed the tune from 8 cylinders to 6 but, I left the engine size at 350. Huge improvement. I then started experimenting with different engine sizes and finally used 360 cu. in. I also increased the pump shot by 15% and the VE enrich by 10%. This made the engine very happy and it starts and drives well.

I don't know if there is a problem with MSD's software or if there is an inherent difference in the fuel curve between V8 and inline 6 engines. I tend to believe it is the latter because on my 235 we started with a VE table for a V8 engine and ended up adding a lot of fuel to it. It would be interesting to do a similar engine with the FAST system and see if it suffered the same problems.

This is probably way more info than you wanted, but maybe someone will find it helpful.

Not at all to much info! LOL! Thanks for all of it! I was considering ordering it for my 292 6 banger. It probably would perform better in it do to the fact it is lager cubic inch. But thanks.

[leddzepp]

Clifford Intake and a Holley 390. I used this setup on all my Jeep CJ inline sixes. You will be very happy.

[NobleSix]

Originally Posted by diceman50

This is probably way more info than you wanted, but maybe someone will find it helpful.

you actually answered a few questions i have had for the longest time!

im trying to start with a holley 390 / offy intake... so far i have a 390 that needs cleaning / rebuilding. i dont know what it came off of, just gonna start with .50 jets and go from there.

it gets kinna cold around where i am so intake heat is pretty much a given, but i want to run long tube headers. im not sure, i think the offy intake is ready to go as far as plumbing in water from the engine to heat it. that saves on having to buy a heat plate, but if not, hafta get a plate to heat that carb. its basically as the name implies, a plate that you mount either under the carb or under the intake manifold, and plumb into the engines cooling system to provide heat. although the offy will bolt on to the stock exhaust manifold, so no plumbing needed, if you go that route.

those fuel injection systems are lookin like a pretty sweet setup tho... i wonder how well itll run in a turbo setup.

also tall tires might be a possibility, you didnt mention what transmission you were going to put behind this beast. both of mine still have the 4 speeds in em. doin freeway speeds at 3-3500 kinda sucks, and ill take every couple hundred rpm i can get.

since nobody said it yet, leo santuccis book, the chevrolet inline six power manual 2nd edition. its a good read with alot of helpful info.

inliners.org has a great board on it and some pretty helpful people. look up tom lowe on there, hes a great guy with lots of dyno info on these engines equipped with these parts, and theres many others wih a plethora of other info, you need only ask!