engine breakin - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crackajacka · 09-16-2003, 03:53 PM

ok i was wondering how long would i need to break in a new gm 350 engine. what oil should i run for initial break in? Should i run a synthetic with break in additive. and then switch back to regular oil or should i run synthetic for 40,000 miles then go back to what i was using which was valvoline max life. just curious because i need to start gathering parts and oils n such because i got a loan from my moms bank (i have no credit) and they had the check printed out before i even completed the app. and my bank took 4 days to tell me no. wierd huh....

Prerunner1982 · 09-16-2003, 04:57 PM

i ran mine 500 miles below 45 or 50 mph. i dont remember exactly but i changed the oil a couple times in the first 3000 miles or so... i used regular oil. have been told not to use synthetic on break in. and to not switch back and forth.

apstguy · 09-16-2003, 09:45 PM

Run conventional for the break in then if you want to use synthetic you can.

**Captkaos** · 09-17-2003, 10:24 AM

I broke mine in like all the other motors. Non-detergent oil and 1500 rpms for 15 minutes. Then drove it for 600 miles and changed the oil.

LOHRTBT · 09-17-2003, 11:01 AM

I broke mine in like I was going to drive it. Not raggin on it but I did get on it from time to time. Yes Full throttle. Have done that with every new car I have owned ...same goes for this one. Never had a failure or problem. And....all my cars stock to stock run better than others just like them.

I did use a cheaper oil for the first 500 miles then switched to synthetic

**Captkaos** · 09-17-2003, 11:24 AM

Quote:

Originally posted by LOHRTBT
Never had a failure or problem. And....all my cars stock to stock run better than others just like them.

I have broken all mine in with no failures and once broken in, I have driven it like I planned to drive it...... I drag raced the 454 THE day I broke it in.

LOHRTBT · 09-17-2003, 11:54 AM

see...Im not the only one who does this!! haha
Hell, Im not about waiting a month or so to see how my new motor runs!! lol
I WANT TO KNOW NOW!! haha

bigblock73 · 09-17-2003, 03:54 PM

I am with Chris and Dave...break em in like you are gonna drive them. I have only had to break in one engine...the sucker never let me down and never missed a beat...not to mention...the damn thing didn't even lose any oil whatsoever!! I wish I could have kept that small block...but I sold it to finance the big block.

-Jeff

**swervin ervin** · 09-17-2003, 04:40 PM

I babied mine around for a little, but if you think about it, look at all the performance engine builders. They put them together, although put together rather nicely, bolt them to a dyno, do the initial breakin, change the oil and filter, and then hammer the hell out of them to see what they will do. If they are going to blow, they want to know about it then.

This reminds me of the guy I used to help with his dirt track car. He had a 350 built by the pros. He goes to pick it up and they had it on a dyno. They had done the initial breakin before he got there. Now it was time for the dyno pulls. They proceed to rev that thing to 7500-8000 grand. Brand new engine. We are all waiting for it to blow all to hell, but the engine builder said, if it blows, so what. I'll build you another one.

LOHRTBT · 09-18-2003, 09:58 AM

That is my outlook on it, If something is weak...break it right away while its under warranty.

There are plenty of conflicting opinions on it but some do belive the ONLY way to seat the rings is by getting on it immediately.

Nvbowtie · 09-19-2003, 04:56 AM

I just broke mine in Non-detergent oil and 2000 rpms for 20 minutes and changed the oil/filter after break in.

09-16-2003, 03:53 PM	#1
crackajacka Stylin Join Date: Sep 2001 Location: Tuttle, OK Posts: 620	engine breakin ok i was wondering how long would i need to break in a new gm 350 engine. what oil should i run for initial break in? Should i run a synthetic with break in additive. and then switch back to regular oil or should i run synthetic for 40,000 miles then go back to what i was using which was valvoline max life. just curious because i need to start gathering parts and oils n such because i got a loan from my moms bank (i have no credit) and they had the check printed out before i even completed the app. and my bank took 4 days to tell me no. wierd huh.... __________________ Ive been traveling for some time, with my fishin pole and my bottle of shyne. Most Girls like finished products and just dont understand what a good addiction does for you http://www.paulwall.us/

09-16-2003, 04:57 PM	#2
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	i ran mine 500 miles below 45 or 50 mph. i dont remember exactly but i changed the oil a couple times in the first 3000 miles or so... i used regular oil. have been told not to use synthetic on break in. and to not switch back and forth. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

09-16-2003, 09:45 PM	#3
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,087	Run conventional for the break in then if you want to use synthetic you can. __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

09-17-2003, 10:24 AM	#4
Captkaos www.73-87chevytrucks.com Join Date: Dec 1999 Location: Birmingham, AL Posts: 6,935	I broke mine in like all the other motors. Non-detergent oil and 1500 rpms for 15 minutes. Then drove it for 600 miles and changed the oil. __________________ Chris Lucas 1973 Chevy C-10 1978 GMC Jimmy (2WD) - SOLD 1987 R10 twin turbo LS 1991 R3500 SRW CrewCab 1985 K5 diesel swapped project 1989 K5 2WD conversion w/ Vette susp Project Captkaos Customs 73-87chevytrucks.com

09-17-2003, 11:01 AM	#5
LOHRTBT BeWarE tHe eViL CrAnkTOe! Join Date: Oct 2002 Location: Yukon, OK Posts: 3,605	I broke mine in like I was going to drive it. Not raggin on it but I did get on it from time to time. Yes Full throttle. Have done that with every new car I have owned ...same goes for this one. Never had a failure or problem. And....all my cars stock to stock run better than others just like them. I did use a cheaper oil for the first 500 miles then switched to synthetic __________________ ~Dave~ You can call me Mike, Mike Oxlong - 1986 Chevy SWB - Stock for now - *1986 Chevy Custom SWB* *Stolen 6/26/05* - 1985 Chevy SWB SOLD - 1999 T/A Some mods www.cardomain.com/id/ramairdave AIM Screenname - Jester84

09-17-2003, 11:54 AM	#7
LOHRTBT BeWarE tHe eViL CrAnkTOe! Join Date: Oct 2002 Location: Yukon, OK Posts: 3,605	see...Im not the only one who does this!! haha Hell, Im not about waiting a month or so to see how my new motor runs!! lol I WANT TO KNOW NOW!! haha __________________ ~Dave~ You can call me Mike, Mike Oxlong - 1986 Chevy SWB - Stock for now - *1986 Chevy Custom SWB* *Stolen 6/26/05* - 1985 Chevy SWB SOLD - 1999 T/A Some mods www.cardomain.com/id/ramairdave AIM Screenname - Jester84

09-17-2003, 03:54 PM	#8
bigblock73 yeller Join Date: Oct 2001 Location: Twin Cities Posts: 13,824	I am with Chris and Dave...break em in like you are gonna drive them. I have only had to break in one engine...the sucker never let me down and never missed a beat...not to mention...the damn thing didn't even lose any oil whatsoever!! I wish I could have kept that small block...but I sold it to finance the big block. -Jeff

09-17-2003, 04:40 PM	#9
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	I babied mine around for a little, but if you think about it, look at all the performance engine builders. They put them together, although put together rather nicely, bolt them to a dyno, do the initial breakin, change the oil and filter, and then hammer the hell out of them to see what they will do. If they are going to blow, they want to know about it then. This reminds me of the guy I used to help with his dirt track car. He had a 350 built by the pros. He goes to pick it up and they had it on a dyno. They had done the initial breakin before he got there. Now it was time for the dyno pulls. They proceed to rev that thing to 7500-8000 grand. Brand new engine. We are all waiting for it to blow all to hell, but the engine builder said, if it blows, so what. I'll build you another one. __________________ Mike 1985 Chevy C-10

09-18-2003, 09:58 AM	#10
LOHRTBT BeWarE tHe eViL CrAnkTOe! Join Date: Oct 2002 Location: Yukon, OK Posts: 3,605	That is my outlook on it, If something is weak...break it right away while its under warranty. There are plenty of conflicting opinions on it but some do belive the ONLY way to seat the rings is by getting on it immediately. __________________ ~Dave~ You can call me Mike, Mike Oxlong - 1986 Chevy SWB - Stock for now - *1986 Chevy Custom SWB* *Stolen 6/26/05* - 1985 Chevy SWB SOLD - 1999 T/A Some mods www.cardomain.com/id/ramairdave AIM Screenname - Jester84

09-19-2003, 04:56 AM	#11
Nvbowtie Registered User Join Date: Jul 2001 Location: Laughlin, Nv. USA Posts: 700	I just broke mine in Non-detergent oil and 2000 rpms for 20 minutes and changed the oil/filter after break in. __________________ www.unlimited2u.com/chevy Bill 1980 Chevy C-10 Silverado 1988 Chevy Blazer Tahoe



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