Gutless Wonder

[Jims86]

yeah, Lot of folks get drawn in by the HP figures, then think "WTF" when they get left at the line by a plain jane goodwrench stock replacement or TBI truck.
4 choices these days for Trucks, GM stock replacement, some call it the "target engine", 87-95 Truck engine, there are 2 versions to choose from; L31 Vortec, and finally th HT383. I mention only these engines for ease of install under original carbureted or TBI applications, there are also the conversion engines, if you want to go the more modern LS, duramax, or cummins route.

 

[towjoe]

I had a 78 C20 crewcab I bought once with a (rebuilt) 350 in it. run great just driving it around, but once I hooked the trailer on it it wouldn't pull itself. I changed carburator, distributer, the usual with no improvements. finally decided to tear into engine and found out it was a 267 V8 with 350 heads. swapped in a good 350 and fixed it right up.

 

[Jims86]

The cam is a big issue though. funnier than **** to see guys say, "my truck is the ****....got a corvette motor in it!". "Motor"...SMH.

 

[fallguy]

I think I've made some headway.

1. Timing set at 10 degrees.
2. Vacuum advance set to 10-12 degrees...it was turned all the way in.
3. Silver and blue springs put in distributor to replace stock springs.
4. Pass side vacuum port was being used on carb, but I should have been using drivers side lower port as I have no smog control systems on the truck. That port was full of silicone from PO so had to clean out.
5. Also on the carb I was pinned in on the top notch of the fuel regulator adjustment arm (no clue as to it's real name) which was allowing for a rich condition and dumping in wasted gas. I moved down a notch to midway and think I gained some power when under load (maybe under load it was running rich and drowning itself in gas?).

My tires now roll off of a dead start and I can feel the vacuum advance kinking in down low and up in the higher range. Better throttle response. Let's see if it stays this way....or will it create issues for me down the road? Guess we'll see!

 

[Jims86]

Sounds like you are talking about the pump drive link...makes sense, rich bog.

 

[HotRodPC]

yeah, Lot of folks get drawn in by the HP figures, then think "WTF" when they get left at the line by a plain jane goodwrench stock replacement or TBI truck.
4 choices these days for Trucks, GM stock replacement, some call it the "target engine", 87-95 Truck engine, there are 2 versions to choose from; L31 Vortec, and finally th HT383. I mention only these engines for ease of install under original carbureted or TBI applications, there are also the conversion engines, if you want to go the more modern LS, duramax, or cummins route.

Targetmaster Motors is what the GM replacements were called many years back and those did get a bad reputation and why some people don't like these Goodwrench Replacements motors that are BRAND NEW Heche En Mexico motors with 4 bolt mains and powder medal rods with Nodular Iron cranks instead of just standard cast cranks. I'm aware of 4 people with those GoodWrench motors, 1 of them being my K1500 that has approximately 10,000 miles on it when I bought the truck. It has an Eddy EPS intake, Eddy Carb, and headers. I'm totally satisfied with it for what it is so far. It's not fast, but it's no sled either. Has no problem getting on the freeway with 3.73 gears and 31 in tires pushing a front axle and carrying a Tcase to boot.

 

[Jims86]

Thats what mine is...its a vortec block that came with the old smogger heads.

 

[fallguy]

.98 primaries
New Air horn gasket
New Accelerator pump piston
Metering Rods. 71x47
#5 plain step up spring

Still gutless so I'm gona try leaning it out some more.

Thots on where to set my timing?

 

[HotRodPC]

Are you 100% certain your cam timing is correct? Seems you're doing alot and still gutless? I mean it's still a low compession emission compliant engine but still, it should have at least enough power to get out of it's own way.

Have we discussed gear ratio yet? Maybe that's the problem. My 454 is a gutless wonder too, but with 3.21 rear gears and OEM 31in tall tires, I'm sure that's why. If I'm doing 60mph in 3rd and nail it, it'll get down with the program and won't go back into 3rd until 90mph with my foot to the floor. So I know the motor has power, it's just gutless in the lower rpm and low speeds due to the tall gear ratio.

 

[hirschdalechevy]

Bummer more crate motor blues , (seen a lot of this). Mismatched part's , mass produced , no quality control , etc..... Sorry to say fallguy but you may be trying to get power out of this thing and it may never happen.If you want to keep your set up and try to make it run you need to start with checking your cylinder pressure , (compression is power) , and go from there. The best thing you can do is a head and cam change. Yon can mess around with all the bolt on stuff and tuning but you need to know what cranking pressure you have to start with . A cam change can help but it's not going to give you a 100lbs torque or anything like that. Smaller chamber heads will be the way to go to bring the compression up.Then you can pick a cam that suite's your rpm range.You can roll up to 185lbs cranking pressure with the right cam and still be good on pump gas , some guy's go a lot higher but it gets tricky with cam choice , quench and timing.

I will bet that the dished piston's are way down in the deck and with stock large cc heads with that cam you have really low cylinder pressure.A cam change can bring it up but that has it's limit's and if you go that far why not change the heads while you are there.

A buddy of mine bought the 330 horse gm crate motor from summit and it was the biggest pig I have ever been in.He took it back and got his money back , (lucky) and we built a flat top piston , vortec headed motor with a 268h comp cam. It felt like 150lbs torque and a 100 horsepower gain over that crate motor in the same truck with no other changes.

Just my 2 cents , sorry for your pain.

 

[HotRodPC]

Very True, Dish pistons and 76cc (Advertised 76, but could be more or less but usually more) makes for a low compression motor. They claim 8 and 8.5 on the crate motors, but I've heard some being low as 7.6 and that is just way low IMO. I've dealt with 2 of the crate motor that came in trucks I've purchases. Luckily, both seemed to have run well for a stock motor. Eddy intake, Carb and Headers was the only adders.

 

[GreaseDog]

So I'm a bit confused as to why we're talking about cam swaps, when we know the thing has not been properly tuned.

The very first thing you need to do is figure out which of those timing marks, if either, is correct. Then, and only then can you begin to tune it properly. Pull the number one spark plug, and stick a dowel rod or pencil into it's hole. Rotate the engine over using the center harmonic balancer bolt (5/8"socket). When the piston gets to the top of it's travel, check the marks. One of them will be close to the center of the large notch in the indicator. If it doesn't, then you need to address that, first and foremost.

OP makes mention if timing being set at 10 degrees initial, and 12 degrees advance. How it's this being measured without a properly identified timing mark? 22 degrees total timing is not nearly enough.

 

[fallguy]

Update...if anyone cares... ;-)

Split the carb and installed;
71/47 rods - main jets .098 - #5 orange spring- new fuel pump plunger

Main jets were .95 from what I could read on them.

Passenger side float hung down 2" and drivers side hung down 1"...so fixed that too to 1" hang for both. Also grabbed a 7/16 drill bit and adjusted floats at top too....per Edelbrock spec.

The plunger hole I'm on is the middle one and I have slight hesitation on acceleration. So I'm thinkin I need a bit more gas so I'm going up to the top hole to test.

I also am not sure what my secondary jets are set at...but I'm thinking .101 is the way to go as it flattens out in power as we get moving or try to pass someone.

On the issue of timing....it's impossible with the damn harmonic balancer...I don't get it. So I did it the old fashioned way....truck warm, block vacuum port, put into drive and hold brake, increased timing to the point of hearing it pinging slightly. Test drove...louder pinging as I approached 60. Pulled over and backed off timing until pinging stopped. Feel more power down low but still flattens out up top leading me to a secondary jet change.

 

[350runner]

Try leaving your vac advance unplugged and see if you can go for a lil more timing. I'm thinking it's just providing too much mechanical advance. If it still pings back it down if not let it ride ;-)

Sent from the dust in front of you!