Camshaft Question

[bucket]

Might as well bore it now.

 

[davbell22602]

Might as well bore it now.

Why? I can get pistons for the 4.080 bore spec. The 4.077 spec wasnt right after I rechecked it today.

 

[bucket]

Why? I can get pistons for the 4.080 bore spec. The 4.077 spec wasnt right after I rechecked it today.

Because the main reason not to bore is saving the cost of new pistons. Now you need new pistons anyway. Might as well bore it so you know it's nice and true, run the rings you want on new pistons, and then drive it for 100K.

 

[HotRodPC]

Might as well bore it now.

I agree 100%. What's another $150 - $175 or so for machine work to the block and have it completly brand new motor. You'd be a fool not to if you are buying pistons now.

 

[HotRodPC]

Because the main reason not to bore is saving the cost of new pistons. Now you need new pistons anyway. Might as well bore it so you know it's nice and true, run the rings you want on new pistons, and then drive it for 100K.

And with the right rings, and taking care of the motor, you can probably get more than 100K out of it, where are with a re ring, you'd probably get 50K before you start burning oil again. Even an old shcool motor with todays motor oils, and using some chromoly rings, I'd think you could get a good 150K and maybe even 200K miles out of it.

 

[davbell22602]

I agree 100%. What's another $150 - $175 or so for machine work to the block and have it completly brand new motor. You'd be a fool not to if you are buying pistons now.

So bored it to 40 over? I bet its more than $175 bore the 390.

 

[HotRodPC]

So bored it to 40 over? I bet its more than $175 bore the 390.

I have not had a block worked on at a machine for a long time, but in the 80s, it was $8 per hole to bore and hone, so $64 for any V8, a 6 cyl at $8 per hole is $48. Then it was $25 for hot tank and mag, then $25 for cam bearing and freeze plug install. So for about $125 back then you could get a V8 done. I figured $175 now. I honestly don't know. Even if it were $200, to make the motor NEW for all the work and money you'd have in it after buying pistons, that extra $200 is going to take you 3 maybe 4 times further. Just my opinion.

 

[davbell22602]

I'm run the block by carquest and get take on boring it for new pistons to see what they recommend and same on milling the 64 390 tbird intake in the other thread I started.

 

[konakustoms]

What are these spots on my camshaft? Is it ok to still use cam or should I replace.

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Hard to tell from the pic but looks to me like normal oil marks from the lifter rolling off the lobe. I build alot of performance motors at work & yes you can reuse a cam with new lifters, we have done it alot.....just break the cam and New lifters in like a new cam setup with zink additive. Dont reuse ur old lifters if the cam mic's out good because looks like you didnt mark the lobes they came off of. That timing chain is junk also....... If ya need the math to tell lift on the cam let me know and I will post it. Bad pic but just looks like normal lifter float on the downside to me...lol

 

[konakustoms]

Piston ring groove cleaner with a spin dial. I'll check it out.

We use a groove cleaner in the shop but if ya break a old ring in half ya got a ring groove cleaner for free
Use cast rings on a hone job (re ring) the molys or moly top ring set won't seal up rite and gap ur rings also........dont make the refresh hard and expensive ok

 

[HotRodPC]

We use a groove cleaner in the shop but if ya break a old ring in half ya got a ring groove cleaner for free
Use cast rings on a hone job (re ring) the molys or moly top ring set won't seal up rite and gap ur rings also........dont make the refresh hard and expensive ok

So there you go Dave, now person #2 giving the same advice. But, do keep in mind with a fresh bore and those new pistons you are talking about, you'll be able to go with your chromolly or molly rings that your teacher told you about. You might want to also update your teacher and let him know, you don't use upgraded rings for a re ring because they are not likely to seat. Just saying !!!

Welcome KonaK !!! Nice to have some more knowledgable and experienced help on board.

 

[davbell22602]

So there you go Dave, now person #2 giving the same advice. But, do keep in mind with a fresh bore and those new pistons you are talking about, you'll be able to go with your chromolly or molly rings that your teacher told you about. You might want to also update your teacher and let him know, you don't use upgraded rings for a re ring because they are not likely to seat. Just saying !!!

Welcome KonaK !!! Nice to have some more knowledgable and experienced help on board.

My teacher heard of the moly rings not seating right but he never had that problem on a rering. He also never heard of boring a block for new pistons either. He told me my cylinders were fine and just needed honed to touch up the cross hatch.

 

[HotRodPC]

My teacher heard of the moly rings not seating right but he never had that problem on a rering. He also never heard of boring a block for new pistons either. He told me my cylinders were fine and just needed honed to touch up the cross hatch.

You obviously don't get it. NOONE is saying you have to bore the block for new pistons. What is being said is, YOU MAY AS WELL bore the block since you are buying new pistons and have a brand new fresh clean bore that will ensure round cylinders, no ridge, and no wear at all. Pistons will likely be the same price for STD size or .030 over or .040 over. You'd also be increasing your cubic inch a little bit, maybe 6 inches or so, and also raise your compression a hair for more power. Its all up to you. With some of this info you're getting from your teacher, I'd have to wonder if could really reccomend his class for new student recruits.

 

[davbell22602]

You obviously don't get it. NOONE is saying you have to bore the block for new pistons. What is being said is, YOU MAY AS WELL bore the block since you are buying new pistons and have a brand new fresh clean bore that will ensure round cylinders, no ridge, and no wear at all. Pistons will likely be the same price for STD size or .030 over or .040 over. You'd also be increasing your cubic inch a little bit, maybe 6 inches or so, and also raise your compression a hair for more power. Its all up to you. With some of this info you're getting from your teacher, I'd have to wonder if could really reccomend his class for new student recruits.

Ok, I'll see about checking them with a bore gauge. The main and rod bearings are 020 USA.

 

[89Suburban]

I build alot of performance motors at work & yes you can reuse a cam with new lifters, we have done it alot.....just break the cam and New lifters in like a new cam setup with zink additive...

Really?