Breaking in a race engine?

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doogievlg said:
If I'm not in low 13 or high 12 range now then I screwed up bad and will be taking a break from the hobby.
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Don't take a break, just get out to the next T&T and get some numbers. Might not feel faster at this point with some street testing, but I think you'll be surprised how much you'll really pick up at the track with those heads. I'd be looking for the MPH numbers.....That will show what kind of power the new engine is really making. Once that's established, you can tune from there. I agree that deep in the 13's is achievable at this point, and maybe beyond that depending on how efficient the torque converter is.
 
I think you would benifit greatly with lower gears .
I would go with a set of 3:91's
I think you could benifit from a different intake manifold ?
I had a 284/484 cam in a 70 340 duster and it pulled really hard !
Never got to track test it ?
My buddy had a mid 13 sec Camaro he said my duster would beat it ?
I started with 3:23 gears then 3:55 next 3:91 then last 4:56
4:56 was to low but fun from 0 to 100
I think 3:91 were a good match .
What distributor are you using ?
 
Well my truck is out of commission at the moment do it depends on when my friend gets off work. Hopefully it's in time to get my car out to the track.
 
doogievlg said:
I've been doing nothing but worried. I seem to remember being able to floor it from a stop and spin the tires real good. Now I romp it and it will spin them for about twenty feet. Could this be because I took around 100 pounds off the front of the car. Now it's hooking better? With street tires!
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Did you have Hoosier QTP tires on before?....because they will hook WAY better than any street tire.

I would not worry too much till after you get a chance to run it and get a time slip...it might be all in your head and the car might run just fine, who knows. Good luck.
 
Nope. Slicks are getting mounted today hopefully. This was on a street tire. I'm rationalizing it in my head by saying taking all the weight off the front is just causing the car to hook better on the street.
 
The 284/484 is soft on the bottom end. Did you degree it? If so - what did you put it at?
 
I put the cam in back in February. I wrote down the info on the short block in one of my many notebooks back at the shop.
 
Back in the day we always ran our race cars out on a deserted stretch of highway before heading to the track. Never wanted to tow 4hrs just to find out something stupid that we could have found at home.
 
If you are afraid it is going to blow up....leave it home in the garage...LOL
 
I'm not worried about it blowing up at all. I'm confident that I put it together right. I'm just worried that I spent all that time and money for not the gain I was expecting.
 
Loading the trailer up in the morning and should be able to get a few runs in before I have to be at a wedding. I'll post my time slips and maybe a video from the track.
 
doogievlg said:
Loading the trailer up in the morning and should be able to get a few runs in before I have to be at a wedding. I'll post my time slips and maybe a video from the track.
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:thumleft:...Be safe tomorrow and have fun at the wedding...
 
Spent the morning driving around trying to find a place to mount my slicks. That didn't happen so I put the street tires back on and then found a broken valve stem on the trailer. Today wasn't my day so the dart went for a short cruise then back in the garage until next weekend.
 
doogievlg said:
Spent the morning driving around trying to find a place to mount my slicks. That didn't happen so I put the street tires back on and then found a broken valve stem on the trailer. Today wasn't my day so the dart went for a short cruise then back in the garage until next weekend.
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:eek:ops::banghead: Hope the wedding goes better! :D
 
Here's my 1/4 race cam with the new split rods,along with the new vented pistons.



After 3-4 hard runs the times settle down and become consistent.

 
Check out hundreds of Youtube dyno videos of race engine builders. After cam break in they check everything before doing their dyno pulls. And they dont go to 3000 RPM and "baby" them. If you buy a dyno tested engine, the rings have already seen the stratosphere before its even shipped to you. Agreed, this is controlled and a little different from abusing an engine with 0 miles. By babying I mean it doesnt take 800 miles. Accelerate and decelerate a few miles and go. Thats what we always did on our sportbikes as well.
 
Well i put the light on it again and I guess I was way off the first time. Initial was set at 10 and total was 20. I put initial at 16 and total at 32 and now she is burnin the street tires off:)
 
Take it to Edgewater and run the snot out of it. I always could tell when the rings had found a home, because the car would start running a lot harder. About 5000 RPM in second gear, usually.
 
sst3193 said:
Take it to Edgewater and run the snot out of it. I always could tell when the rings had found a home, because the car would start running a lot harder. About 5000 RPM in second gear, usually.
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I'm going to try and get out this weekend. I don't have a trailer yet so I have to see when my friend will get back from work. I am a bum.
 
What they do on a dyno break in is break in the cam, shut it down. Check everything (i.e lash, coolant, oil etc) Then do a couple "baby pulls" like 2500-5000. Check vitals and then let it rip
 
Yeah - I have the operator load it a little, and go up and down in rpms for 5 minutes or so. By then the rings should have seated fully. Then check for leaks, check lash, check timing, and pull it.
 
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