well time is ALMOST here , i soon as summit delievers my tranns line i ordered yesterday, i will be firing the old 351 , still need some parts to drive it , but i am very close , back to the oil question whats the best oil weight to use on a new engine? or does it matter would 20-50 work better to protect it ?
1,000 well if i am goin to rob a thread i might as well do my own... just noticed that this is my 1,000 post just had to celebrate my own milestone ok back to the thread yeah i just need something to break the engine in, nothin fancy
30w break-in... Then go to a multi-weight 'dino' oil for a while. After the engine is good and broke in, then go for a lightweight synthetic. Don't use synthetic on a 'new' engine, it can interfere with the rings seating and other proper break in objectives. However, once a good break in is done, synthetic will add power and long life to your engine. Good luck Dave
I was told by my engine builder I was told by my engine builder for the 408 stroker to use 15-40 Delo 400 or 20-50 Valvalin for break in and for general use. I never heard of Delo 400 before. He also stated to use 3924 Autolite plugs, gap 035. Do not use less than 91 and no more than 100 octane fuel. My fireing order is 13726548 with a timing of 36. james comet
That's aweful thick oil. Thick oil saps HP and creates heat. If an engine is new, (not a pure race engine set up loose) it should not have enough bearing clearance yet to run that kind of oil. You will also run longer on start up before the oil flows... Bad idea. I like Mobil 1 0w40 myself. Flows very easy when cold, flows like 40w when hot. Best of both worlds. 0w30 or 5w30 might be the way to go on a tight street engine. It comes down to what you have learned personally about oil and how you use that info. Dave
on start up..i use the cheapest oil i can find..run the break in time for the cam and then dump it, then put the gooder stuff in and run it about 500 miles and dump it again. this is to wash out any metal left in the motor from the machine shop...change the filter on the second dump...JMO... ...frank...
He is giving you real good advice. Delo 400 is a good oil but if you are going to do oil sampling start it right after your break-in. Delo uses copper in it as a lubricant / coolant aid. Just be sure to tell them that you are using Delo so the high copper won't be confused with bearing wear. I like Valvoline and I use 20-50 in my older engines. I don't have the clearances in my new engine to start it out on that heavy an oil but if he is telling you to use it then you probably have the clearance for it. I prefer a smaller plug gap - but then I can put up with a bit of misfire at an idle for the high load power that I get with a .028" gap. The octane rating is for 9 - 10 to 1 compression and you are probably on the edge of 10 to 1. The firing order is normal for the 351W and late model roller 302's.
The weight of your oil needed depends on your bearing clearances and local temperature. Someone in Arizona probably won't need the same oil as someone in Maine during the winter. As far as what's needed for break-in, are you running a flat tappet cam or roller, do you have moly-faced rings or cast iron? It all can make a difference. For a flat tappet cam I would add a can of GM's engine oil supplement at break-in. Moly-faced rings seat almost immediately, no need for a nondetergent oil. Cast iron and chrome-faced rings take longer to seat, a nondetergent oil will speed that up. I also like to use 85-90W gear oil as an assembly lube, it's loaded with moly and stays put until initial fire up.
"Ouch", metal shavings in a fresh block out of a machine shop. Not a good thing or caring machinest(used to be one). Hot tanking, air blow and lot's of brushing in the oil passages etc. Then after getting it home, wash the entire block with warm soap and water. Rinse and rinse and rinse, scrub the hell out of the bore's and dry with a clean white cloth. You will be amazed how many scrubbings it takes to get a clean rag. Use Marvel Mystery oil on the bore's and anything else you don't want rusted. OOP"S, back to the oil deal, Valvoline 10-30 until a few thousand miles, then Mobil 1, same weight. Took some of my pistons and rod's out, and could not hardly wash the M 1 off with mineral spirits. Damn good oil, say's I.
