383 in M1008...No Power!

[Recovry4x4]

Valve lash too snug? Cam timing? Who built the engine??

 

[ODdave]

Uhhh.....Propane is most certainly supplied thru a carb. Rock crawler rigs FREQUENTLY do it. It allows the engine to remain running at any angle. Just got to slightly modify the existing carb. Several companies manufacture and sell kits. I know a guy that owns a propane company and just about everything he owns is converted to propane.

LOL, Yea? hook propane up to the fuel line on your carb and give it a shot, let me know what happens. . The existing carb may be left on as a way of metering air but in NO WAY is used to introduce fuel into the engine.

 

[bearboley]

I second the convertor. Its gonna be a no win for you when you put that high stall in there you gas mileage will be in the crapper.if its a 383 drivability will not be good they tend to make great power but no low ends,you gotta spin em. I think you need about a 3500-4000rpm stall.usally you need a converter that has a stall speed 2000 rpm higher than your cam makes power at

 

[Efituned]

Valve lash too snug? Cam timing? Who built the engine??

Valve lash is good. I installed a timing chain/gear set and everything was in time. I am unsure of the engine builder.

I went by the shop today and had someone look at the carb. He said everything checked out good. Fuel pressure and flow was also good. He went through the ignition timing and said it was off a few degrees, but even with that fixed it still didn't help.

He said that either the cam timing is off or the cam is to big for the engine. I am leaning towards putting a converter with higher stall. The engine seems to have great power once going down the road or when the rpms are up. Could it be that I have a bad converter or one with a lower than stock stall?

 

[Bob H]

Valve lash is good. I installed a timing chain/gear set and everything was in time. I am unsure of the engine builder.

I went by the shop today and had someone look at the carb. He said everything checked out good. Fuel pressure and flow was also good. He went through the ignition timing and said it was off a few degrees, but even with that fixed it still didn't help.

He said that either the cam timing is off or the cam is to big for the engine. I am leaning towards putting a converter with higher stall. The engine seems to have great power once going down the road or when the rpms are up. Could it be that I have a bad converter or one with a lower than stock stall?

That confirms the need for a higher stall.

 

[Efituned]

I will be installing a converter this weekend and I will report back.

I ordered a transmission vacuum governor (red stripe) for a gas engine and it didn't really help with the shifting. With the diesel engine the shifts were firm and on point. Now they are soft and I am in 3rd gear around 20mph. Nothing was changed on the transmission other than today with the vacuum governor. What should I do to get the shifts firm and late?

 

[ODdave]

You ordered a vacum modulator...... The governer is under the 4 bolt cover on the rear / side of the trans.........Lighter weights mean later shifts. Put the original modulator in and change the governer.

 

[197thhhc]

Has anyone gone through your distributor. Are you running a big cap HEI or something else. When we build stroker engines we always have to recurve the distributor. Sounds like you may have to change to lighter advance springs to wake the engine up. What is your base timing set at and what is your total advance.

 

[Efituned]

You ordered a vacum modulator...... The governer is under the 4 bolt cover on the rear / side of the trans.........Lighter weights mean later shifts. Put the original modulator in and change the governer.

Where can I buy one built like the original? Another reason for taking the original one out is because the vacuum nipple was sort of bent and crushed so I threw it away.

Also where can I buy different weights or a governor?

Has anyone gone through your distributor. Are you running a big cap HEI or something else. When we build stroker engines we always have to recurve the distributor. Sounds like you may have to change to lighter advance springs to wake the engine up. What is your base timing set at and what is your total advance.

No one has been in the distributor. I bought a new one thinking the old one was the cause of the problem, but it didn't make any difference. I do have the vacuum advance line off. What should I set the base timing to? IIRC anything above 10 deg @ 700rpm starts pinging.

 

[ODdave]

The original would be the one you took out of it... just put it back in. As far as the governer, any decent trans shop or you to a junk yard and pull one from a small block th400

 

[Bob H]

Dave, I thought the governor controls the 1-2 shift when the shifter is left in 1st.
The adjustable vacuum modulator can alter the shift points. The adjustment screw is inside the vacuum port.
Unless the mid 80's diesel TH400's are different than the 70's
I have mine set for a 5500 rpm shift with WOT and held in 1st. (in my car)

 

[Efituned]

So do I need to get one of these kits with the weights?

B&M 20248 - B&M Governor Recalibration Kits - Overview - SummitRacing.com

Or get a different Vacuum Modulator like this one:

B&M 20234 - B&M Vacuum Modulators - Overview - SummitRacing.com

The new Vacuum Modulator that I put in seems to be non adjustable, but I will take the vacuum line off and check.

 

[Barrman]

To hopefully finish out the propane discussion. Many propane kits, back 20 years ago when there were a bunch of kits out there, had a mixer that bolted somewhere under the hood. Then a hose that hooked into the air filter housing somehow. Turn of the electric gasoline fuel pump, turn on the mixer and the propane/air mixture went through the carb together.

I had such a truck way back when. Gasoline was $1.25 a gallon and propane was about $.60 per gallon.

Yes, it did go through the carb. Just not through the fuel line in the carb. Air venturi only.

Back to the question this thread is about. Go to the Edelbrock web site, down load and print the manual for the carb. I agree your problem is probably the torque converter and transmission settings as discussed already. However, follow the Edelbrock manual for how to set the carb up correctly and it will probably help a lot too.

 

[jw4x4]

It sure does run thru the carb. Not mixed or added to the gasoline, but in it's place. It's the diesels that can have propane injection to boost power, kinda like nitrous oxide omn a gas engine.

 

[phil2968]

I recommend reading this article about duel fuel conversion to clear up how it works. Also look what they have on the dyno! A M715!
Dual-Fuel Propane System Install - 4Wheel & Off-Road Magazine

 

[Efituned]

Well I got the transmission shifting at the right point by adjusting the screw inside the vacuum modulator.

 

[ODdave]

It sure does run thru the carb. Not mixed or added to the gasoline, but in it's place. It's the diesels that can have propane injection to boost power, kinda like nitrous oxide omn a gas engine.

I think we may be argueing 2 different things, It may got THROUGH the carb, as in through the venturis as stated but like I said, is NOT INTRODUCED through the carb.

Like I said the carb can only be used as a air metering valve only. It dose NOT control the propane.


As for the weighted governer & modulator, they actualy work agains eachother to control shift points. you whould have to read the hydraulic flow chart to understand.

 

[Efituned]

I ordered the B&M Tork Master 2400 stall converter and new flexplate, which I will be installing tomorrow morning. The flexplate and converter I have now is a 4 pad and does not match the new 3 pad converter I ordered. Who really knows what converter is in the truck now...

I will post some pictures of the truck and engine tomorrow.

 

[Efituned]

Got the new 2400 stall converter in and man what a difference. I did a little power brake test and it will smoke the tires by barely touching the gas. I can now get the truck to idle properly in gear. Everything seems to be great with this swap, other than a small oil leak at the lower timing cover.