Help me find the umph in my 360

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dustyaman

dustyaman

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So fresh build on another 360 engine. I sold my last one. This one came out of 1986 360 d150 pickup.
Took the whole engine apart and did a full rebuild. Bearings, rings, summit 1798 camshaft, .030 over pistons, speedmaster as cast heads, edelbrock air gap intake, 1905 edelbrock carb, Doug's headers, The 727 came out of the same truck. No rebuild it shifts ok for a basic 727 And converter is stock also. It cruises great. With 3.55 gears around 3000 rpm I'm at 50 mph. Now I have timing at 20 degrees initial... it seems to love that the most. I have it on manifold vacuum advance timing. It goes up to 50 by 3000 rpm.
My problem is I feel like it's just sluggish and should have way more power. In drive at full throttle it shifts 1-2 at 3800 which is just getting into the power of the cam. And 2-3 is 4000. Now if I try to manually shift.. at full throttle I will shift it at 4000 but it won't actually shift until 6000. I hate that. Is it the converter that's keeping the power away? Or is it my poorly choice camshaft. I realize that camshaft has a higher rpm power curve. Seems my Transmission is keeping that power away based off its shift points. I need advice to go from here. Oh BTW afr is around 14.0 to 14.5 during cruise and 12.5 at full throttle.
 
Here are a few pics of my car

20230706_064100.jpg


20230526_213925.jpg
 
Did you degree the cam? That's a good bit of cam for a stock converter. I don't know what you were thinking there.
 
RustyRatRod said:
Did you degree the cam? That's a good bit of cam for a stock converter. I don't know what you were thinking there.
Click to expand...
The transmission was a afterthought. To good of a deal to pass up. In the future I want to do the a41 package from silversport.
 
What pistons, did you cc the heads, compression ratio, degree cam? need a little more info.
You could use a better converter.
 
moparlvr166 said:
What pistons, did you cc the heads, compression ratio, degree cam? need a little more info.
You could use a better converter.
Click to expand...
Stock height pistons just .03 pistons. I basically just went dot to dot on putting the cam in. The heads I took straight out of the box. Looked for issues didn't find any and put them on the engine.
 
With the replacement pistons did you measure how far down in the hole (deck height), are they flat tops? The speedmaster heads, did the say how many cc the chambers are, aluminum or iron? just trying to guess on comp ratio.
How tall are the rear tires?
Nice looking ride, are you going to put A/C back on?
 
moparlvr166 said:
With the replacement pistons did you measure how far down in the hole (deck height), are they flat tops? The speedmaster heads, did the say how many cc the chambers are, aluminum or iron? just trying to guess on comp ratio.
How tall are the rear tires?
Nice looking ride, are you going to put A/C back on?
Click to expand...
If my memory serves me right the were .110 in the hole. And these are the speedmaster aluminum heads.
 
6000 6200 should be a good shift point
1 adjust kickdown
2 do a cranking comp test
3 ditch that carb for a holley dp 650 700 750 the 700 is nice has the rear 50cc acel pump
 
a-bodyguy said:
6000 6200 should be a good shift point
1 adjust kickdown
2 do a cranking comp test
3 ditch that carb for a holley dp 650 700 750 the 700 is nice has the rear 50cc acel pump
Click to expand...
OP said stock converter and 3.55' s, and a cam that could possibly hurt his bottom end
I would choose a vacuum secondary like an AVS, Thermoquad, or Holley 750 vac sec
 
Last edited:
Brooks James said:
OP said stock converter and 3.55' s, and a cam that could possibly hurt his bottom end
I would choose a vacuum secondary like an AVS, Thermoquad, or Holley 750 vac sec
Click to expand...
ive run a bigger cam same car 3.23s 27 tall tire stock verter torker door stop and 650 dp 750 would have been better
instant tire smoke if i so wanted
a properly tuned dp is beter then a 1905 edeldog 8 days a week twice on sundays
thermoquad is the only non holley i would use
either you can tune or you cant its not the carb problem
learn how to tune
 
Guessing the 727 kickdown needs better adjustment.

Looks like a locker cable kickdown setup.

The farther back the pressure valve on the trans (kickdown lever) the later it will shift.

How about a picture of the throttle linkage / kickdown setup with the air cleaner off so we can see what your setup configuration is?

20230709_183213.jpg


☆☆☆☆☆
 
Full throttle upshifts at 3800-4000 is because you have a truck trans. Needs a higher rpm governor. Try 5600-6000. Don't need to pull the trans to replace the governor - just the extension housing. A&A, among others, has a wide selection of governors.

50 mph at 3000 rpm is not right for 3.55 gears. I'm guessing your speedometer is wrong. I think I checked mine with GPS app on my cell phone. Again, if the speedo gear is what came with the truck trans, probably not right. The speedo gear can also be replaced with the trans in the car.

Not sure why the delay of manual shifts, but I'm thinking the truck valve body might have something to do with it. Shift kit??

I'd say it's certain you need a better torque converter.

Pistons .100 in the hole at TDC were not the best choice, but my 360 (short block dates back to 1990, when 360 piston choices were very limited) runs well with that same issue.
 
That cam want's minimum 9 to 1 your closer to 8 to 1, your choice more converter or smaller cam. you said base timing at 20 you didn't say anything about centrifugal specs?
 
dustyaman said:
Stock height pistons just .03 pistons. I basically just went dot to dot on putting the cam in. The heads I took straight out of the box. Looked for issues didn't find any and put them on the engine.
Click to expand...
Therein is most likely where the problem lies. It is imperative to degree the cam. Otherwise you have no IDEA where it is installed. It could be 12 degrees retarded for all you know.......and I've seen it! If it was mine, that's the first thing I would do. Get the timing cover off and degree it. Even if you find it's dead on, which very likely it AIN'T, it will be worth all the little bit of trouble.
 
Both are lokar cables for kick down and throttle. The pressure lever goes all the way back at full throttle. That engine picture is old and has a different linkage setup now. I will send a pic of what it looks like.
 
Always like to see the factory throttle / kickdown linkages for the mopars with the Edelbrock 1481 linkage adapter to get the proper geometry on the throttle Swing and the kickdown linkage throw.

th-1102564162.jpg


Screenshot_20230709-232017_Firefox.jpg


Screenshot_20230709-231518_Gallery.jpg


Lokar cables are an alternative, but are real finicky to get the geometry correct and get them adjusted proper so you get full throttle opening and proper rpm shifts with the kickdown adjustment.

Here is what "oldkimmer" had to say about them a while back:

Screenshot_20230709-232440_Firefox.jpg


☆☆☆☆☆
 
dustyaman said:
So fresh build on another 360 engine. I sold my last one. This one came out of 1986 360 d150 pickup.
Took the whole engine apart and did a full rebuild. Bearings, rings, summit 1798 camshaft, .030 over pistons, speedmaster as cast heads, edelbrock air gap intake, 1905 edelbrock carb, Doug's headers, The 727 came out of the same truck. No rebuild it shifts ok for a basic 727 And converter is stock also. It cruises great. With 3.55 gears around 3000 rpm I'm at 50 mph. Now I have timing at 20 degrees initial... it seems to love that the most. I have it on manifold vacuum advance timing. It goes up to 50 by 3000 rpm.
My problem is I feel like it's just sluggish and should have way more power. In drive at full throttle it shifts 1-2 at 3800 which is just getting into the power of the cam. And 2-3 is 4000. Now if I try to manually shift.. at full throttle I will shift it at 4000 but it won't actually shift until 6000. I hate that. Is it the converter that's keeping the power away? Or is it my poorly choice camshaft. I realize that camshaft has a higher rpm power curve. Seems my Transmission is keeping that power away based off its shift points. I need advice to go from here. Oh BTW afr is around 14.0 to 14.5 during cruise and 12.5 at full throttle.
Click to expand...
20 initial? Will it take more? cause 4 more degrees can make significant difference..or even 5 give that 'snap'..
Imo you need at least 2400-2600 stall or it will act like a truck motor. What camshaft?
 
George Jets said:
Always like to see the factory throttle / kickdown linkages for the mopars with the Edelbrock 1481 linkage adapter to get the proper geometry on the throttle Swing and the kickdown linkage throw.

View attachment 1716112659

View attachment 1716112660

View attachment 1716112658

Lokar cables are an alternative, but are real finicky to get the geometry correct and get them adjusted proper so you get full throttle opening and proper rpm shifts with the kickdown adjustment.

Here is what "oldkimmer" had to say about them a while back:

View attachment 1716112661

☆☆☆☆☆
Click to expand...
I think the Lokar stuff is one of the biggest frauds ever on hot rod guys. I've seen a lot of it. It's chinsey as hell and it sucks. The factory stuff works far better. You got that right!
 
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