Another "Rods-only" engine thread
 

*calling patsmx5*

My plan is to stick manley rods in my stock 99 block that has 42k on it. Buy FMs "big flex fuel kit," use e85, ID1000s, and max out my little gt2560.

While I have the bottom end apart, my brain is thinking, "NEW RINGS? HONE WALLS? MIGHT AS WELL DO MAIN STUDS. WHILE IM AT IT BETTER STICK NEW BEARINGS IN THERE. HEAD STUDS...etc"

Is any of that really necessary for an engine that really isn't worn? It has 42k on it. I bought it from an old guy who babied it every Sunday to get ice cream. And I average 1000 miles a summer.
(This car will be used on the street 99% of the time. 1% at 1/4 mile)

I think I can truly do rods only and the engine will still last another 40k at least. Thoughts?

I would never ever re-use rings and not hone walls. Ever
Everything else is fine if you really want to keep it to the bare minimum.

Since rings are about the only thing I could confidently clearance at home..I'll bite the bullet for Mr.18psi. As for honing...are u just talking one of those gadgets that goes on a drill for diy home use? Wouldn't the crank have to come out then? I don't like all that stuff..more chance for me to install incorrectly

yes drill hone
no crank doesn't need to come out

Honing is not a simple or easy thing to do correctly. You need to put a specific surface finish into the cylinder at a specific angle, while keeping the cylinder perfectly cylindrical to within ~0.0003" or so. If you do it wrong, the engine will either burn oil or have a huge amount of blowby because the rings never sealed up. If you think you can do that with a bottle hone on a cordless drill, go for it. I would never attempt that in a million years, because paying a professional to do it on a machine designed for the job will only cost you ~$100 or so, and then you know it's done correctly.

Which is why I emailed you the other day about the cost of a built engine. I completely understand price vs done right and reliability. If I were to send the block to a machine shop for a hone, I'd do an over bore for bigger pistons as well. Which would lead me to an "allofit" bottom end. Which is not what im going for right now.
"If it ain't broke, don't fix it"
if the rings and cross hatching are in the condition that im guessing theyre in, they should have no problem sealing for another 40k....right?

Wait, reusing bearings is kosher? That might tempt my scope-creep to flare up again...

I would do main studs and head studs as a "while I'm in there" because they're easy bolt-ons, but then I probably wouldn't ever do a rods-only build.

--Ian

There's a difference between a low budget backyard/garage build and a full on built engine from a company/shop.

Many, and I mean MANY here have successfully honed their shortblocks with no issues. But this obviously assumes you know what you're doing. If you don't, you gotta pay.

I still stand by my statement of not re-using rings if you attempt this

Doesn't using stronger main studs change the main to crank clearance?

I know on our LS motors rod bolts are not the best. Apr bolts are a nice upgrade but they change the tolerances.

Would arp bolts on the rod caps change the clearance between the crank and rod bearings?
The reason I dont want to change anything besides rods is the fact that there are too many clearances, tolerances, variables, etc that can and will be out of spec if I attempt

You've done a comp/ld test and know for a fact your rings are flawless?

I have heard people claim that you need to line bore the main caps to use main studs, OTOH many people have installed them without doing that and I've never seen anyone say it was a problem. I've done it on two engines now, no problems.

I also don't know that I buy the theoretical argument. I'm a software guy, not an ME, but I would think a main stud can be stronger without necessarily giving more clamping force. If the clamping force is the same, then I don't see how the clearances change.

--Ian

I like to do "everything or nothing" so i would never just put rods in. Fully built, or unopened engine, but that's just me.

No. But it would be a must if I decided to re use the rings. Im sure they are not "flawless" bc they have 42k on them. My argument is that I've seen plenty of boosted engines that have never been opened up make it above say 150k miles. So if I have no reason to believe my engine in its current state couldn't do the same, then why replace things that don't need to be replaced and risk have wrong clearances. I guess an argument against that could be that bearings wear faster at 300whp than 250whp? Idk though

My main concern would be doing all that work and spending quite a bit of money (since all the gaskets won't be exactly free), and then having one of the rings not re-seal or find out you have to rip apart everything and do it all over.

I guess that's where the slippery slope really comes into play.

I'm scratching my head.. You don't need an overbore. Get a proper hone (if it even needs it, cross-hatching on these blocks lasts damn near forever), new rings, new gaskets, re-assemble. And your rods of course.

Don't over think it, 42K is very low mileage.

"Slippery slope." If I ever take this block to a machine shop, I'm doing everything

Of course it would, that's why caps are line-bored and line-honed with the caps torqued to spec, blocks are bore/honed with deck plates, etc. Sometimes the idea of "fixing" or "upgrading" something sounds great, but understanding the right way to do it escapes them.

OP, at a bare minimum you're going to need rods, a set of rings, and a bottle hone. I tried doing rods only, reuse rings and not hone, and it burned tons of oil. Redid it with new rings and honed it, and it worked very well. Most shops will hone a bock for 10-20 bucks/hole, it's really cheap if you don't want to do it yourself. I've done it myself, and paid others to do it.

If the clamping force is the same, then it's fine. Nobody using ARP mains torques them substantially less than stock though to achieve this (doing so negates the benefit of installing them in the first place...), so they will have a much higher clamping force when installed due to finer thread pitch and low friction lubricant supplied by ARP.