Author Topic: rebuilt engin startup  (Read 3579 times)

pjbizjak

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rebuilt engin startup
« on: September 05, 2018, 11:03:57 PM »
Hi all, Planning to fire up my fresh rebuilt 302 in a few days(have other things to do first) and I would like some feedback on how long to let it run, what rpm etc. I will prime the oil pump first, pan filled with royal purple 5w30, topped off with amsoil assembly lube. Set the valves @ 24 cold, it's has the comp cam 30/30 grind. heard both settings 24 & 30 lash? Using super hi test gas. Engine put together with original 68 crank, pink rods, J&E pistons new valves & sprins basically upgrading the 302. block bored to 40 over was 30 over before. I'll try and answer any questions.

Thanks Pete

jcihos

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Re: rebuilt engin startup
« Reply #1 on: September 06, 2018, 12:05:43 AM »
When my 383 was broken in we stayed between 1500-3000 rpm for around 30 minutes if I remember correctly. Then we allowed it time to cool down. My engine builder put in Joe Gibbs Driven break in oil at a 20w50 for break in then I was able to switch to VR1 10w30. Total run time for my engine on the dyno that day was about 4 hours while we dialed in timing, jet sizes etc.

BillOhio

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Re: rebuilt engin startup
« Reply #2 on: September 06, 2018, 12:58:19 AM »
5w30- seems pretty thin??
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Kelley W King

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Re: rebuilt engin startup
« Reply #3 on: September 06, 2018, 11:40:09 AM »
Your cam instructions will dictate the first half hour. After that if it is in the car I vary RPMs for awhile watching all the vitals. They say new ring materials don,t really need to "seat" but I still see a little blow by for a while.
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Stingr69

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Re: rebuilt engin startup
« Reply #4 on: September 06, 2018, 12:46:38 PM »
Dont forget water in the cooling system and a fire extinguisher.  The GM Engine Break-In Oil Additive is the best.  If you have factory stamped steel rocker arms you want to run the tighter lash spec.  If you are using aftermarket rockers you can set them at the looser spec. The tighter spec was based off of the factory pieces. 

If you want to be persnickety you can set the valves just zero lash at .020" LOBE lift (not at valve, measured at pushrod top travel) to lash aftermarket (or any other ratio) rockers with a GM spec 30-30 cam.  You need a dial indicator for this.  The GM spec lobes have a .020" slow lift portion of the ramp where all valve lash is taken up.  That is the exact point where all the lash is removed when the lash is set perfectly.  Snug the lash at the valve to zero while at .020" LOBE LIFT, rotate the cam way off the ramp (it is LONG) and measure the clearance at the valve. Use that measurement at the valve for setting all the valves with any rocker arm and a GM 30-30 cam. 

rodent

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Re: rebuilt engin startup
« Reply #5 on: September 08, 2018, 06:39:00 PM »
If you're running dual or triple valve springs, pull the inners out and reinstall after run in.

169INDY

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Re: rebuilt engin startup
« Reply #6 on: September 08, 2018, 07:10:00 PM »
Dont forget water in the cooling system and a fire extinguisher.

ONLY Water no coolant please learn from my 1985 Emergency room visit to the "Mary Bridge" Tacoma General Burn center stay. (1967 Camaro 454 Upper Catastrophic Rad Hose failure) Thank goodness only Water my burns could have been much worse.

Stay safe.

JIM
Jim
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RS Copo

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Re: rebuilt engin startup
« Reply #7 on: September 12, 2018, 10:11:33 PM »
Is that RP oil synthetic? It's generally not recommended to use synthetic on break in.

rodent

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Re: rebuilt engin startup
« Reply #8 on: September 23, 2018, 07:36:54 AM »
How did you get on with the startup?

rodent

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Re: rebuilt engin startup
« Reply #9 on: November 27, 2018, 08:08:47 AM »
Crickets........

crossboss

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Re: rebuilt engin startup
« Reply #10 on: November 27, 2018, 02:23:12 PM »
Hi all, Planning to fire up my fresh rebuilt 302 in a few days(have other things to do first) and I would like some feedback on how long to let it run, what rpm etc. I will prime the oil pump first, pan filled with royal purple 5w30, topped off with amsoil assembly lube. Set the valves @ 24 cold, it's has the comp cam 30/30 grind. heard both settings 24 & 30 lash? Using super hi test gas. Engine put together with original 68 crank, pink rods, J&E pistons new valves & sprins basically upgrading the 302. block bored to 40 over was 30 over before. I'll try and answer any questions.

Thanks Pete



Id recommend you use conventional oil (at least 30W), and some zinc additive especially with a flat tappet (non-roller) cam. Prime it before you fire it up is preferred. Run it with water only, and for at least 20 minutes @ 2,200 RPMs.
Just another T/A fanatic. A new project in the works.

 

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