Where's the Wow?

-
Freezerman

Freezerman

Well-Known Member
Joined
Jul 4, 2013
Messages
318
Reaction score
114
Location
MN
Hey guys,
Got my car back together finally and the engine is a major disappointment! It is a 360 and my old 318 was better. I'm not expecting 13 second 1/4 s but I can barely spin a 225/60. Runs smoothly though. Some advice would be great!
1972 Dart
1974 stock 360 short block, with 34k. Still had crosshatch in cylinders. Pistons down .080
X heads cc'ed at 68, .029 head gaskets. Should be low 8s for CR? XE 268 cam.
Edelbrock 600 with 71 340 intake, Edelbrock square to spreadbore adapter plate. 70 340 exhaust manifolds with 2.5 inch with h pipe exhaust.
24* initial timing, all in at 2200 for 34 total. 3.23 rear, 904 trans, Pat Blaise high stall 360 converter, may be too low? Cranking compression is between 140 and 150.
Any ideas?
 
Sorry forgot, I did degree the cam. It was within 1/2 degree so installed straight up. Cranking compression at 140 to 150.
 
Sounds like lack of compression isn't helping much.
 
1st thing is your expectations are too low. Not only would I expect 13's with a X-head, XE268 cam, good exhaust, but I would expect to pound 13's easily.

You are looking for something major....
  • Cam lobe wiped out? you can confirm without taking the intake off
  • Timing Chain off a tooth or two? I actually did this once (LOL) by lining up the dots on the key way instead of the timing dots. Ran good, but was slower than a stock 170 six
 
I don't think I lost a cam yet. It runs really smooth and it was unimpressive right away and been trying to tune it. Don't have more than 50 miles since putting together. I suppose I could have the timing off, I lined up the dots but?
 
Freezerman said:
I don't think I lost a cam yet. It runs really smooth and it was unimpressive right away and been trying to tune it. Don't have more than 50 miles since putting together. I suppose I could have the timing off, I lined up the dots but?
Click to expand...
you can loose a lobe trying to turn it over. You can check this fast, but it's a little messy. Pull the valve covers. Use a paint marker and draw a line on each pushrod. Start it, the paint lines should rotate. IF not.....oh oh :(
 
Did you find actual TDC and it lines up with balancer mark?
 
I was able to get instant start on break in, but again any thing is possible. Would it idle smooth with a bad lobe?
 
The compression figures around 8.4-1. I'm wondering if it would be happier with a .050" duration in the 2teens. Comp recommends 9.25-1 for that cam.
 
Yes, I did find exact TDC and check the balancer. It is not a new one but it hasn't had power since the first time I took it for a run. I don't think it has slipped.
 
Freezerman said:
I was able to get instant start on break in, but again any thing is possible. Would it idle smooth with a bad lobe?
Click to expand...
I'm not suggesting a cam lobe. I'm saying that you have something major wrong. You don't change a jet size or up the timing 2* and find what your missing. It will be a major, and you'll know it when you see it.
  • throttle only going part way open? Back mechanicals coming open or is the choke arm prohibiting it?
 
You probably just don't have enough compression, start turning up the timing till it pings, I had the same problem with a chevy put together with the wrong heads, piston combo so we had to run the timing at 50 degrees. I was going to change the heads but it ran good enough and never did.
 
That's what I'm afraid of, it's something major. The throttle does go all the way open, but has more of a rushing air sound, maybe through the adapter plate? Also I forgot to say it seems really slow to wind up after about 4 grand
 
brian6pac said:
You probably just don't have enough compression, start turning up the timing till it pings, I had the same problem with a chevy put together with the wrong heads, piston combo so we had to run the timing at 50 degrees. I was going to change the heads but it ran good enough and never did.
Click to expand...
Yes, lower compression motors can get away with more timing. I personally do not like it when the age old method is used...... advance initial and lock her in at 34*. Let the engine decide where it wants to run. It may want only 16* initial but 44* full advanced...... just say'n.
However, I believe there is definitely enough compression to run run run :D
 
I did stop raising initial at about 24 to 26 because I thought that was getting pretty high. Would it idle smooth with decent vacuum (14 to 15) if it had a bad lobe?
 
Freezerman said:
That's what I'm afraid of, it's something major. The throttle does go all the way open, but has more of a rushing air sound, maybe through the adapter plate? Also I forgot to say it seems really slow to wind up after about 4 grand
Click to expand...
hmmm.... when I messed up on my timing chain (believe me, I've done gobs of them and then did it wrong... LOL), it acted just like that. I mean it started and idled fine. However, it wouldn't pull or rev. I had the +/- 4* chain. I went dot to dot and accidentally lined up the dot on the crank key instead of the dot on the tooth key. It was slower than a 2.2 K-car with the A/C on. I mean it was bad. Not say'n this is your problem, but just say'n....
 
Freezerman said:
I did stop raising initial at about 24 to 26 because I thought that was getting pretty high. Would it idle smooth with decent vacuum (14 to 15) if it had a bad lobe?
Click to expand...
vacuum gage would NOT hold steady and still. It would bounce around quickly
 
Sounds like something with cam or timing then. The vacuum gauge doesn't hold steady but doesn't bounce a lot either... Maybe timing gear off or marks were bad from factory. I guess first try to check the cam lobes. Would I get good cranking compression with bad cam lobes?
 
Freezerman said:
Sounds like something with cam or timing then. The vacuum gauge doesn't hold steady but doesn't bounce a lot either... Maybe timing gear off or marks were bad from factory. I guess first try to check the cam lobes. Would I get good cranking compression with bad cam lobes?
Click to expand...
yes, well, maybe, because the valves are still opening and shutting. I've personally never lost a lobe, so I generally don't suspect that, but I was using that as a "big bang theory"....
 
Alright, some ideas to check, thank you. I won't be able to get to check on it until tomorrow. So I will recheck vacuum gauge and try more on timing and get back to you. Thanks
 
was cam degreed in advanced? in other words, ground on 110 , LCA, int CL should be 106 CL.
 
Check and see if overlap is at TDC, if its out of time overlap will be way off TDC, it's the easiest way to check just pull off the left valve cover.
 
I'm confused. You say you degreed cam, but then say maybe the marks are off. If you really degreed the cam there should be no doubt. Did you replace valve springs?
 
I did degree the cam it was within 1/2 degree of spec of the XE 268 cam card so I installed it straight up. Yes on new springs. The cam being off statement meant maybe I screwed up somehow and got off a tooth
 
You must log in or register to reply here.
-

Back
Top