Crate engine swap advise please?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

73 C10

Full Access Member
Joined
Sep 29, 2014
Posts
156
Reaction score
1
Location
California
First Name
Scott
Truck Year
1973
Truck Model
C10
Engine Size
350
Guys it's a long story. But long story short, I had to build two VA cans before it worked but, I am hitting the number you guys asked for, almost.

I am now at 10* base set @ 550 RPM , no vac.

I'm pulling 13* of VA between 6"-11" on the 6th notch (5/16" stroke) on the Crane end flop mod. VA can set to the middle of it's 14 turn range.

You must be registered for see images attach


Vac unplugged, I get ~31*-32* at 3000 RPM.

Bogged and bit of rattle. The rattle was brief this time.
 
Last edited:

73 C10

Full Access Member
Joined
Sep 29, 2014
Posts
156
Reaction score
1
Location
California
First Name
Scott
Truck Year
1973
Truck Model
C10
Engine Size
350
Here is the other one I did. This was a AR11. It wouldn't work because, you can't see it in the picture, but there is a doubler welded on to thicken the part. It's double thick, and with the limiter on top of that, it would block the arm. This, in the reverse sense might have been what screwed up the old distributor. But the mechanical was screwed up too.

You must be registered for see images attach


It could be made to work still. I just need to remove the doubler.
 

rich weyand

Full Access Member
Joined
May 28, 2014
Posts
964
Reaction score
162
Location
Bloomington Indiana
First Name
Rich
Truck Year
1978
Truck Model
K10
Engine Size
350
Good! So now we're down to getting the mixture dialed. Your timing numbers are real good for now.

Once the meter is in and you get the mixture dialed in, you can probably go another 4* on base timing, which will increase power across the band.
 

Old77

Administrator
Staff member
Admin
Joined
Aug 19, 2010
Posts
28,264
Reaction score
8,738
Location
Kansas City, Mo
First Name
Jacob
Truck Year
1977/1990/1991
Truck Model
C10 longbed/R1500 Burb/R3500 Dually
Engine Size
350/350/454
Update? @73 C10 how are things now? It's been a couple days.
 

73 C10

Full Access Member
Joined
Sep 29, 2014
Posts
156
Reaction score
1
Location
California
First Name
Scott
Truck Year
1973
Truck Model
C10
Engine Size
350
Hi guys,

The a/f meter is in. And a fuel pressure gauge.

The meter said:

11.5 Startup cold
12.5 Light peddle through the neighborhood
12 At the stop sign
9.5 Light foot up to 45 MPH
10 Cruising 45 MPH
13.5-14.5 Lightly letting off from 45 MPH
9.1 Heavy foot to 45 MPH
16 (Maxed) Rolling through the neighborhood

Now, I've read that I should only try to use the a/f meter to tune cruise and WOT, so we'll simplify things here.

That would be:

10 Cruise
9.1-9.5 WOT

So, it looks to be wet and in need of a smaller jet? So I'm thinking I'll put the stock needle in and see what the meter says for something to compare.

There is a consistent bog when pressing the peddle from idle.
There is another consistent bog when letting off power.

It doesn't like to start the last few times. Even before I emptied the line, cutting in the gauge.

The Fuel pressure started out at 5.75 before the drive and was at 3.6-4 after.

You must be registered for see images attach


You must be registered for see images attach
 
Last edited:

rich weyand

Full Access Member
Joined
May 28, 2014
Posts
964
Reaction score
162
Location
Bloomington Indiana
First Name
Rich
Truck Year
1978
Truck Model
K10
Engine Size
350
Hi guys,

The a/f meter is in. And a fuel pressure gauge.

The meter said:

11.5 Startup cold
12.5 Light peddle through the neighborhood
12 At the stop sign
9.5 Light foot up to 45 MPH
10 Cruising 45 MPH
13.5-14.5 Lightly letting off from 45 MPH
9.1 Heavy foot to 45 MPH
16 (Maxed) Rolling through the neighborhood

Now, I've read that I should only try to use the a/f meter to tune cruise and WOT, so we'll simplify things here.

That would be:

10 Cruise
9.1-9.5 WOT

OK, so you're rich as hell in most modes, which is what I figured. Cruise circuit looks lean. The bog is in transition.

Which rods are in it now?

You want to get to 13 idle, 14.5 cruise, 13.5 power, and 12.5 secondaries.

Idle is idle. Cruise is driving along at 30-40 mph without accelerating. Power circuit is accelerating but not into the secondaries. And secondaries is with your foot on it.

Idle is adjusted with the idle mixture srews on the front of the carb. In (clockwise) is leaner. Cruise and power are the two steps on the rods in the primaries. Secondaries is the jets on the back barrels.
 

rich weyand

Full Access Member
Joined
May 28, 2014
Posts
964
Reaction score
162
Location
Bloomington Indiana
First Name
Rich
Truck Year
1978
Truck Model
K10
Engine Size
350
Those are the numbers with 68/57 rods in .098 jets? Wow. That's really rich.

I assume the 9" springs, right?

You can tune idle, cruise circuit, power circuit, and secondaries (WOT). Not sure why you think you can only use AFR meter to tune cruise and WOT.

Cruise at 10, should be 14.5. 100/10 is 10, 100/14.5 is 7, so you only want 7/10 or 70% as much gas as you are getting. So the second number should be 68 on the rod as a next try.

Power circuit looks like 9, should be 13.5. 100/9 is 11, 100/13.5 is 7.4, so you only want 7.4/11 or again about 70% as much gas as you are getting.

Simplest may be to put .092 or even .089 jets in there with the same rods and see what numbers you get. .092 should be about 80% of the gas you have now in both circuits, and .089 would be about 70% of the gas. They're only $7 a pair, plus shipping, but you do need to take the air horn off to get at them.
 

73 C10

Full Access Member
Joined
Sep 29, 2014
Posts
156
Reaction score
1
Location
California
First Name
Scott
Truck Year
1973
Truck Model
C10
Engine Size
350
Any updates on this? Where you at with it, 73C10?

I've been messing with it for awhile with the meter and I think the main circuit must be leaking somehow and giving me extra fuel. My cruise number is good at 14.5. But power can get down to 12. Getting on the highway there is a rich bog with the peddle down. Cruising on the hwy. is about 12.5.

That's with a 95 main, 6557, and .083 secondary.

I tried a 92 main and it just gets too lean.

The rod I need doesn't exist. I need a 6459. That's only a delta of .005". I don't think that is right.

I have a feeling the venturi booster gasket might be bad. When I rebuilt the carb, the kit didn't have the gaskets in it so i cut my own. So that's got to be what to look at next. I just can't find those gaskets by themselves.

I cant get where I need to go. Like I said, I think it must be getting extra fuel somewhere.

I guess I might try a .080" secondary. I've got one already.
 
Last edited:

rich weyand

Full Access Member
Joined
May 28, 2014
Posts
964
Reaction score
162
Location
Bloomington Indiana
First Name
Rich
Truck Year
1978
Truck Model
K10
Engine Size
350
You still running the stretched 8# springs? Do your step-up pistons move freely?
 

Latest posts

Forum statistics

Threads
42,167
Posts
910,470
Members
33,661
Latest member
eri24
Top