Fresh rebuild, P-1SC or D-1SC during break in before retune?

So my car has been down for 5 1/2 years. Just had the motor freshened up. Not much has changed except new pistons, .030 bore,rebuilt stock heads and cams. Old specs in sig. Car had a P1 Procharger on it with a 3.2" RR pulley. Not sure of the compression but the old pistons were cp-s9822 and i now have Manley 594130C

I purchased a D1 with a 3.4 8 rib before the car broke. Both head units needs rebuilding. They both are disassembled, and will be rebuilt by yours truly. Prev owner stated a little over 500 hp/tq. I saw 478hp/450tq but that was with #8 cyl having issues.

I will be switching over to the 8 rib setup when my timing cover and valve covers get back from powder coating. My question for you guys is can I install the D-1 with the slightly larger pulley without issues from my current tune. My plan is to install the D-1, go 500 miles on break-in oil, another 1000-1500 on dino oil before switching to full syn and taking for a tune. Im trying to only have to put one blower on once as long as its safe to do so with D1. I dont see a issue as I wont be getting into boost that much before a retune.

My options are:
1. Put on P1 with 3.2 6 rib, maybe still change others to 8
2. P1 with 8 rib 3.4
3. D1 with 3.4 8 rib

Thoughts??

Why not just put the blower you want on the car, take it to the dyno and have them do the break in and tune all at once? No need to drive for 500 miles taking it easy, you can do the break in on the dyno with no issues.

^^ what he said.

If you changed the compression much car might not run correctly anyway. We dropped my compression from 10:1 to 9.5:1 and the car wouldnt hold an idle, wasnt seeing enough load after the compression drop.

Helomech74 said:

Why not just put the blower you want on the car, take it to the dyno and have them do the break in and tune all at once? No need to drive for 500 miles taking it easy, you can do the break in on the dyno with no issues.

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Im new to the new motor break in thing. I was under the impression that you needed the time to properly break in and seat the rings(hence 500 miles) especially before makibg 6000+ rpm runs on a dyno. How long does it take to properly break in on tbe dyno?

The rings will seat within the first 20 minutes. If you take it easy during that time they will never seat properly. The last engine I built I got it up to operating temp, made sure there were no leaks, then hit it with full boost. It turned over 100 miles on the dyno a week later.

Will probably just go ahead and throw the D1 on there and see how she idles and run. Gonna give Lidio a call and see if he does dyno break ins but will probably just do it myself. Still might put a few hundred miles on it bwfore takin g it to him if i do the break in.

Dont let her sit there and idle. If nothing else do what i did run it na and beat on it a little bit. Do lots of engine braking.

mustanginky said:

Do lots of engine braking.

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You mean don't do, correct? Engine braking will glaze the cylinder walls very quickly on a fresh motor.

I have always been told the opposite actually. I tried to look it up but cant find any info supporting or saying its bad. But my 2 year old is up and asking 20 questions a minute and making demands left and right lol

The way engine parts are made these days they break in fairly quickly compared to decades back. The technology has greatly improved because manufacturers hate paying warranty claims. (Yes that is the reason because the manufacturers have much more $ to throw at a problem than say Manley) You should be able to put on the head unit you want and just keep it below 4500 rpm for the first 500 or so miles for everything to seat well. I personally think that is more than enough and it will likely be ready much sooner if built correctly.

Think about it this way, car manufacturers don't "break in" the engines, even on high performance units. They get a bit of idle time and a mile or two before they are dropped off at the dealer for someone like me to prep them for the lot. After that who knows how they're driven once purchased. Even the hellcat (yes I work at a mopar dealer) only has a short break in tune in the computer before it gives the owner everything it has and that thing is putting out a bunch.

mustanginky said:

I have always been told the opposite actually. I tried to look it up but cant find any info supporting or saying its bad. But my 2 year old is up and asking 20 questions a minute and making demands left and right lol

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L&M did my short block and it came with their break-in instruction sheet. At the bottom in bold letters it said to not conduct deceleration until after the break in period was over because of the incredibly low cylinder pressures it causes. And pressure/combustion seats rings.

break-in procedure seems to vary just as much as which oil people use. definitely gonna put in the D1 and as long as it idles well, take her out and run it hard for a good 30 mins after burping the cooling system.

Speedboosted said:

L&M did my short block and it came with their break-in instruction sheet. At the bottom in bold letters it said to not conduct deceleration until after the break in period was over because of the incredibly low cylinder pressures it causes. And pressure/combustion seats rings.

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Got it. I always heard it causes a vacuum and pulls the rings out to be seated. Fwiw i did a good deal of it on mine and see no ill effects from doing so.

mustanginky said:

Got it. I always heard it causes a vacuum and pulls the rings out to be seated. Fwiw i did a good deal of it on mine and see no ill effects from doing so.

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The way I heard it is that you want to accelerate hard to get the rings to seat against the cylinder wall. Then use the deceleration to "clean" the bore. So you'd take the engine up to say 5000rpm under hard throttle, then let off and let it coast a bit. Supposedly that lets the oil get up around the rings and clean off the "filings". Is it true? No clue. But I've done the hard hits and let it coast with no issues. I'm not pro engine builder either. I always tell people to do what their builders say in that case.

but when you say coast you mean under engine braking correct? Thats what I was told to do, increasing throttle and rpm with decel under engine braking back to near idle.

DSG2003Mach1 said:

but when you say coast you mean under engine braking correct? Thats what I was told to do, increasing throttle and rpm with decel under engine braking back to near idle.

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Correct.I didn't let it go down to idle. Just back down to cruising RPM.

Helomech74 said:

Why not just put the blower you want on the car, take it to the dyno and have them do the break in and tune all at once? No need to drive for 500 miles taking it easy, you can do the break in on the dyno with no issues.

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I agree, we broke in my engine on the dyno with a blower. No issues a year later. Runs as strong as ever. Doesn't blow any smoke or anything.