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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Stewart G Griffin on July 13, 2009, 03:19:38 PM

Title: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on July 13, 2009, 03:19:38 PM
The original thread was getting to long to sift thru, so i decided to start another one.

We're almost there, as you can see.

One heater hose goes to the radiator, but which of these outlets (inlets?) should i hook the other hose to?

(http://i223.photobucket.com/albums/dd31/sencraig/100_0561.jpg)
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: eventhorizon66 on July 13, 2009, 03:32:06 PM
I have mine at location "B".
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: baddogg79 on July 13, 2009, 06:15:28 PM
mine is on "B" too
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Irish_Alley on July 15, 2009, 12:37:44 AM
B
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on July 15, 2009, 08:21:22 PM
i'm pretty sure it's "B" too at this point.  i will plug "a" or put a temp sender unit in there.

We have, unfortunately(or fortunately depending on how you look at it) hit another unrelated life snag/issue and thus the problem will have to be put on hold again temporarily.  How pathetic.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on July 15, 2009, 11:17:57 PM
P.S.  That is the boring but reliable 305 i had in the garage sittting dormant that i was talking about.  Complete with rochester 2g carb and manifold.  How 50's ish.

Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 06, 2009, 12:15:16 PM
Update:

The engine is finally running (not real smooth---needs tuning adjustments etc., but running)

Will provide more info asap and possibly a video.

Thanks for everyones help in the matter.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: SUX2BU99 on August 06, 2009, 12:48:48 PM
P.S.  That is the boring but reliable 305 i had in the garage sittting dormant that i was talking about.  Complete with rochester 2g carb and manifold.  How 50's ish.



That's what my 81 Jimmy 2wd had. 305 2bbl. Most gutless vehicle I ever owned. Kept me out of trouble (mostly) in high school though :)  Hmmm I did almost beat a guy who had a 83 305 4bbl LWB and straight pipes though...almost  lol
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 08, 2009, 07:51:02 PM
305's don't get enough respect;  i personally love them and think you can get some performance out of them.

No one has any problems with a 283, yet the 305 with 22 more cubic inches is hated.  i don't get it.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: eventhorizon66 on August 08, 2009, 08:00:32 PM
305's don't get enough respect;  i personally love them and think you can get some performance out of them.

No one has any problems with a 283, yet the 305 with 22 more cubic inches is hated.  i don't get it.

I have a problem with anything less than a 350 for a rebuild and 383 for a "from scratch" build.  It's not that the smaller SBC's are bad engines in any way.  It's just that if you are serious about performance, your money is much better spent on 350 and up.

305's don't get respect from people who are wanting to build power.  For a commuter engine, they're jim dandy.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: TexasRed on August 08, 2009, 08:06:19 PM
305's are good for a motor for a small boat and a grocery getter, even then I wouldn't do an all out check-every-clearance rebuild for 400k miles. My grandpa used to drive a 305 with a pop-up camper through some hilly parts of Oklahoma just fine (from what I recall), but really, it's not ideal.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: eventhorizon66 on August 08, 2009, 08:22:52 PM
And another thing.  It baffles me that the 305's ever existed in the first place.  Wouldn't it have been easier and cheaper to simply use a 3" stroke to achieve 5.0L rather than cast a whole new block?  And why was 383 never offered as a factory engine?
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 10, 2009, 10:08:16 AM
1) Probably because they, the engineers, were looking for more of a torque engine---longer stroke.  While still getting decent mpg?


2) Proabably due to mpg;  The 400 is the "monster" torque engine of the sbc family--not really a hi-po engine, more of a hauler.  So, the 383 would have just been redundant because the 350 would fill the bill for performance while getting slightly(but enough for marketing and environmental concerns) better mpg.

These are only my thoughts/speculations on why they did what they did with the above engines.

Plus, gm is just conservative----we are not talking about Ferrari here.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 10, 2009, 12:01:48 PM
So anyways, next i need as much info as humanly possible on the rochester 2G carburetor.

Please provide any/all links possible concerning this carb.   i know this is not an easy task as no-one gives a crap about this carb anymore except in tri-power configurations but even then, multi-carb setups are just not that popular anyways.


1) i'm having problems keeping the engine running below 1000rpms which sounds like the timing is too retarded.   (The engine, does however, sound pretty decent for the brief time i can get it to run at 1200rpm or above.)

Current plan for that would be to keep advancing timing little-by-little before each attempt to start.  i have a battery charger, so testing like this is not nessesarily a problem.
My only concern about this first stategy is that i don't want to damage the starter;   Is 15 seconds of cranking per minute ok?   In other words, i'm letting the starter cool off for at least 45 seconds before cranking a maximium 15 seconds per try.

2) How do you actually start a car equipped with a 2G?

a) when cold?

b) when the engine has run for a few secs but shuts down?   So, the engine is still "cold" but not as cold as if not run for a few hours.   Also, i'm ASSuming in this condition fuel has run thru the carb.

c) When warm?



Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Donut on August 10, 2009, 06:00:21 PM
http://www.oldcarmanualproject.com/manuals/Carbs/Rochester/2-Jet/Manual/MCarbRoch1973__2G.htm (http://www.oldcarmanualproject.com/manuals/Carbs/Rochester/2-Jet/Manual/MCarbRoch1973__2G.htm)
http://www.carburetorfactory.com/expvw23.html (http://www.carburetorfactory.com/expvw23.html)exploded view.

I had one on a Monte Carlo (I think) and if I remember, it started like any other carb.

Have you gone through the carb yet?  A quick overhaul and cleanout can work wonders.  The kits should be available at most auto parts shops for less than 20.00.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 10, 2009, 11:25:30 PM
1) Very good links;  Thanks.

2) The carb is a rebuilt unit, so there's really no need to overhaul it yet.

i'm thinking if cold, then one or two pumps and then release while cranking?

If warm then hold the pedal down halfway while cranking?

i should add that the engine did run quite good 3 yrs ago in this very truck (long, almost tragic story; pls see other posts) with this carb.

And then again a few days ago, again with this carb.   So were close.

i'm thinking there is not enough fuel in the carb or something.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Marc on August 11, 2009, 09:41:07 AM
Are the plug wires routed correctly and connected properly?  Is it backfiring?  You could also have a massive vacuum leak too.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 11, 2009, 09:50:30 AM
i should have mentioned that the engine has run for a few secs, so the distributor is in phase and all the plug wires are routed correctly.  Whether the distributor is timed ideally is unknown at this point.

No, no backfiring.

i think we're ok as far as vacuum leaks as i've plugged the big hole in back for the power brake vacuum booster.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 11, 2009, 07:08:52 PM
Next, i want to run a few scenarios past you:

1) If a carbed engine is cranked and cranked, but doesn't start (for whatever reason) would this flood the engine?

a) how do you know if an engine is flooded?

2) What's a reasonable fast idle speed?
a) in general?

b) For Rochester 2G's?
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Donut on August 11, 2009, 09:03:16 PM
Ok, I'll try with my limited knowledge  :) (These are my opinions, not to be confused with that of a real mechanic)

1) It could, a)I usually pull the dipstick, if the oil reeks of gasoline, change it. Fresh plugs wouldn't hurt either (I've never had any luck getting wet plugs to fire consistently, even after they've "dried out")

2) Fast idle speeds I've usually done by ear. 1100-1200 +/- ?  I believe right now my Q-jet is @1000 for high idle, about 800 "kicked down" I'm working on it now, so that might change. (especially when colder weather moves in and I get my choke adjusted correctly)

b) for the 2g specifically ?

I didn't know the correct starting procedures for a Q-jet until I read them on my sun visor (*chuckle*)

As another disclaimer, I don't think I've touched a 2bbl in 15 yrs.  But all carburetors do basically the same job, meter the air and fuel.

Why I mentioned the rebuild kit earlier, let me tell you a story.  Last summer I bought the kit to rebuild my Q-jet.  The throttle shafts needed to be bushed, and the choke system was completely gone.  Went and bought a re-man unit.  Fired up the truck, couldn't adjust it, one side of the carb was running quite a bit richer than the other.  I tore the carb apart, one of the primary metering rod hangers was bent so more fuel was getting dumped on that side.  Bent it back down even with the other, double checked the float level (a little low, but not to bad) and rinsed out some crud that managed to be in there.  Set the idle mixture, then tried to drive it.  It would pull good for about 30 seconds then fall flat on it's face, like it was out of gas.  If I was at part throttle, I was fine.  Pulled the carb apart again, I thought the float or needle was sticking, i noticed the needle/seat assembly was smaller than what was in the kit.  Swapped them out and I was ok.  It seems like I keep going back to the rebuild kit for misc parts that I need (and the rebuild kit should have complete specs for the carb it's going in.)

I just changed the cam and heads.  Driving around (after break in) I had a flat spot about 2000 rpm, pulled carb apart again and it's got crud in it (earlier today)  I must have knocked some loose when I changed filters and the hard line.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 13, 2009, 12:16:42 AM
UPDATE:

i got it running normally.  i got fast idle to around 1000-1200 and normal idle around 800 and in gear 500-600.  i think it was just a case of the engine just needed to be run/turned over for a while to "shake the cobwebs out" so to speak.  It actually started to idle pretty smoothly after a few seconds of sputtering.

i took it for a short test drive and there is serious and immediately noticeable lack of torque and power as compared to the crate 350, but i don't really care---i'm just using this as transportation.

So, alas, i think we can finally close the chapter on this problem.

What did i/we learn this time?

a) don't give up.

b) i tend to get a little worked up/nervous/ emotional when it comes to car problems;  i need to stop thinking so hard and just get in there and do it.  i think this can apply to life in general as well.

i would sincerely and profusely like to thank anyone and everyone who tried to help me.

eventhorizon was always there for me, especially with the diagrams.

But really, thanks to everyone who helped.

Life is good again.........even if only briefly.
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: eventhorizon66 on August 13, 2009, 12:58:37 AM
Glad to hear you've got your truck back on the road.  Did you end up keeping your 350 to rebuild someday?
Title: Re: "NEW" PROBLEM(S), PART 2:
Post by: Stewart G Griffin on August 13, 2009, 09:40:53 AM
Yes, i still have the crate 350.  It's my full intention to rebuild it.   i just don't know when because of time contraints.


Actually, i have a hunch that the short block doesn't even need a rebuild----i think one of the heads was warped or cracked causing one of the cylinders to fill with water and hydrolock causing the valve to break.


But we'll see.


P.S.  i also learned that i need to marry or live with a doctor or lawyer or investment banker ($$$)

and 2) the choke works just fine---opens up after about 2 mins.