Boring and milling a 350

[Guest]

I was wondering what was involved in boring out a buick 350 .030 over. What is involved with the heads? Crank? Pushrods? I am also going to mill the heads. I know I need to get adjustable pushrods. If I mill it, do I need to worry about valve clearance? The pistons are stock, crank is stock, rods, and pushrods are stock. Hell, the whole engine is stock, except for the cam I believe. <P> Give me as much info that you have PLEASE.

[Guest]

First a moment to gripe:<BR>You ask specific questions but give no info!<BR>What year is the motor?<BR>Your original compression ratio?<BR>What type of pistons will you be using?<BR>Specs. on the cam?<BR>How much are you planning on milling the heads?<BR>ect.<P>Anyway, DON'T take this personal, its not directed at you specifically, I see this alot on this (and other) sites.<BR>Your asking good questions that are very important to an engine rebuild so keep asking, but they require specific related information.<P>But to answer your question:<BR>(Condensed version)<BR>Block mounted in a Boring machine, Boring bar comes down, has a Carbide bit on it that machines your cylinder (rough finish), then the cylinders are honed to fit your pistons (they will have to have your new pistons before they will bore the block)<BR>The best thing to do would have your machine shop SHOW you whats involved, much easier and you will get a better understanding.<BR>Ask them your clearance questions also, they can tell you how to check your piston to valve clearance (or check it for you).<BR>Side note:<BR>Carefull on milling the heads, if you go to much you will have to mill the intake also to get proper alignment (the shop should point this out also).<BR>If your just having them "surfaced" then thats not a problem.<BR>If your looking for more compression, do it in the pistons since you have to buy a new set anyway.<P>Once again, don't take this reply as a slam at you, it's not intended that way.<P>Good luck on your rebuild.<BR>Dale.

[Guest]

I have a 73 block. It has 8.5:1 compression ratio. I am boring it .030 over, or "30 over" Whatever the jargon is. I would like the compression ratio to be around 10:1 and 11:1. Stroking it, Poston makes a stroker kit for the 350? Right?<BR>My cam is .262 duration Isky Cam. That is also getting changed to a Buick-Designed cam.<BR> I don't know much about Valve clearance at all. Numbers wise. I don't know how much I would mill it. I am probably going to do one, or the other, because If I wanted to do all that, I would want to put it into a smaller car. Not one that weighs 4000 pounds. Like the one I got. If I was going to do all that, Why wouldn't I just go out and get a 455 to do that to? [Thinking Aloud]<BR>Anyway, I am leaning towards Boring it out, and getting High compression pistons, and not milling. All the valve trouble is spooking me a little bit. Because I blew a valve on the previous 350 I had, and my Dad had a valve problem on his 350, so thats why.<BR>Sorry about all the gaps in the info, I am just having to much fun thinking about my car will do after the modifications. <P><BR>Thanks Dale on the info <p>[This message has been edited by LVSeminole (edited 07-12-2000).]

[Guest]

Sounds like you have a good plan!<BR>I guess you know that when you get around 10:1 and above you will have to run racing fuel (or at least a mix of racing and 93).<BR>Caution: DO NOT run a motor that detonates (spark knock) or your reward will be broken pistions and rings!<P>As far as valve clearance, unless you go with a huge cam (well over 500 lift) you probably won't have any problems.<BR>But check it anyway or have the shop check for you.<P>Basically you just assemble the motor as usual for the short block.<BR>Put modeling clay on top of one piston in the valve areas.<BR>Put one 1 head with an old gasket and torque down.<BR>Install one set of pushrods for that cyclinder and adjust.<BR>Use soild lifters or hydraulics with springs designed for this test(their very weak), if you use hyds. with reg. springs the lifter will compress giving an inaccurate reading)<BR>Turn motor over by hand carefully a couple of times then remove the head.<BR>If memory serves you should have a minimum of .100 between closest point of valve to piston.<BR>BUT DO NOT TAKE MY WORD FOR THIS, CHECK WITH THE MACHINE SHOP.<BR>Hope this helps and good luck.<BR>Dale

[Guest]

Dale is right with the compression. 91 octane detonates at 9.75:1. This is very, very bad to say the least. Especially since pump gas has really been sucking bad these last few months, and I don't just mean price wise. Everbodies cars have been running like crap lately, we need to overthrow opec! lol