Engine builders/Machinist, got a cylender surface Q

[fords2fast4u]

So I bought this 69 351W all forged stroker a couple months ago and I'm about to put it together and build it. AND I noticed some lines/scratches along two of the cylinder walls. They're just big enough or deep enough to feel.

I'll probably pull those two pistons to check the rings, but my question is, how much damage is enough to cause a problem? It doesn't look like it was something from a valve dropping or pistons blowing, but it just looks like the rings were scratching the wall surface.

I could hone those two cylinders and replace the rings if they looked bad, but I know the clearance there shouldn't be more than .0038" Can I hone these without causing performance problems with a 10.5/1 high horsepower motor?

I've got about $5200 in this set up so far with all new top end and then another 2500 in the new TKO. I'd hate to put this all together and have it smoke or worst case blow up at 5800 RPMs

Here are some pics.

 

[fords2fast4u]

these aren't turning out that well...

 

[fords2fast4u]

just a couple more for good measure. If someone knows a better way to post, please PM me or post it in here. Maybe I'll do a search and try and figure it out.

 

[Vipersix]

I assume you are referring to the vertical line running parallel to the piston travel? It looks very convincingly like the damage done by debris left in the combustion chamber after motor assembly.

The damage done all depends upon your intent and level of perfectionism. You could likely get away with doing nothing to it and your engine would run just fine. 10.5:1 is a pretty reasonable level of compression so I wouldn't expect any problems in that arena. What exactly do you consider "high horsepower"?

If you have a micrometer it would be best to gauge the depth of the scratch. If you can measure it, hone it.

 

[fords2fast4u]

yes, I am talking about those lines. They're not really visible in the pic, but that's just due to resolution.

As I said, they're JUST deep enough to feel, so I'm thinking they're .0010" or so.

I do have access to a machine shop, so I'll micro it tomorrow, and I'm thinking that my only option is to hone it.

And I'm thinking 450-475 FWHP with 150 shot of nitrous on top of that.

But what about sleeving those two cylinders? ? Is that a possibility while keeping the same pistons and keeping cost down as opposed to going with a whole different set?

thanks!

 

[Vipersix]

Personally, I never recommend a sleeving unless your engine is set up for it. Usually creates additional headaches.

If the scratches are not very deep and you are not running a pro class engine (which it appears you are not), a light honing will take out the scratch and still leave you within acceptable clearance tolerances.

 

[fords2fast4u]

honing seems to be the best option. Would i need a new set of rings then? maybe a file fit set?

Do you think i can hone this myself? My dad has a hone and has worked in a machine shop for 22 years, and he would of course help me.

In any case, I'm taking this to a mustang guy and then an engine builder today to get their opinions. I'll let you know what they say.

In the mean time, I see you have a 395W. are you running a roller cam? and what's this business i hear about older blocks that are converted to roller using the 302HO spider style rollers (that I have) having to use reduced base circle cams? This longblock came with the spider style roller lifters and a X303... but now I'm starting to doubt their judgement.

And how do i use a pushrod length checker? lol

thanks a million!

 

[Vipersix]

Holy cow! Enough questions?!?

Would i need a new set of rings then? maybe a file fit set?

Doubtful. Once again, though, it all depends on how much surface needs to be honed in order to get an acceptable clearance and how much tolerance you are willing to accept. In my opinion, file sets are the only way to go for high performance motors. However, high performance seems to be a loose term these days and I tend to hurt people's feelings when I tell them they do not possess a high performance motor. That said, I believe that a file fit ring would be an excess for your motor.

Do you think i can hone this myself? My dad has a hone and has worked in a machine shop for 22 years, and he would of course help me.

With his assistance and demonstration I would highly recommend that you do it yourself. Honing is an easy and relatively quick process which can save you some significant money. It's one of those skills which is quickly fading in the auto enthusiast crowd.

are you running a roller cam? and what's this business i hear about older blocks that are converted to roller using the 302HO spider style rollers (that I have) having to use reduced base circle cams?

I am. Essentially, you must either use a smaller base circle cam or shorter lifters. I used the spider tray on my engine which required a bit of grinding in the lifter valley in order to facilitate the installation of the dog-bones. Another option would be to use the linked lifters instead of standard lifters. I believe this would actually be the better option because you would then be able to use any roller cam you wish. Yet another option would be to buy a roller block. This would also solve your scratched cylinder problem!

And how do i use a pushrod length checker?

CompCams has a great article regarding this.

 

[fords2fast4u]

AND i just found out that I'll have to either order a set of retro-fit roller lifters, or a small base circle cam. I guess these guys put this together wrong. It's a good thing i checked it out before just running the thing.

some fricking people... who puts a standard base circle cam in a retro-fitted block where the bosses aren't tall enough? Someone who doesn't know what the hell they're doing!

Well I guess i don't know everything either, but i know enough to fricking check the things I don't know!

 

[fords2fast4u]

Viper, you've sure been alot of help. Thank you!

So you're saying that you can use a standard base circle cam with the dogbone/spider setup, you just have to grind into the cylinder side of the valley?

I noticed something was wrong when i saw that the dogbones were resting on the cylinder side of the valley and then remembered a SN thread where some guys were arguing about retrofitting the older blocks and whether or not SBC cams were really as bad as people say... so i did some research and it appears that whoever put this X303 in didn't know what they were doing...

P.S. I like my 69 block, with the higher nickel content and thicker main webs! Might not be worth the $500 lifters and $$$ honing tho... damn.

 

[fords2fast4u]

or wait, i think i read your responce wrong... so you ARE running a Small base circle cam and of course the dogbone/spider roller lifters?

 

[Vipersix]

No, you still read it wrong (or else I suck at communicating!). You need to either run a small base cam with the spider tray and dog bones to keep the lifters in the proper alignment OR a normal roller cam with the retro linked lifters. Or in other words, normal cam and retro lifters OR retro cam and normal lifters. I'd recommend the retro lifters so you'll have more cam options.

 

[fords2fast4u]

well I'm just about to quit. It's been a long day.

Last night it was finding out that I need the $500 lifters...
Today, it's that the block is .060 over and the pistons that are in it, are NOT the pistons that were in it when it blew. Cylinder #2 has scratches from an apparent blown piston removal (given away by the nature of the markings, and the fact that they go all the way to the deck, not stopping where the rings would as the other markings do).

Obviously what happened was that the block had debris in it, because jumping rings don't cause 8-9 vertical scratches... then piston 2 went and they took it apart. The block was already .060 over, so rather than sleeving it or scrapping it, they put in spare racing parts that had been run in another motor and slapped it all together to sell as a "complete motor". I wouldn't be surprised if this thing wasn't even balanced.

this is some bull SHlT

So now i have a ruined block, but a high dollar rotating assembly. The options I see are, find a 94-96 roller block and put my crank/rods/pistons in it or sleeve this block. With either option, i think i should strongly consider getting different pistons, because .060 over pistons just don't last and I'll be fighting heat in no time with running this motor at high rpms.

I could go low compression pistons, or i could go back to a 302... the whole fricking can of worms is open and i don't know what to do with the expensive, over-sized ross pistons... there is the "option" of milling the pistons. I MIGHT be able to have that done for free at my dad's shop (he works for Muncie). AN EXTREME measure, and almost unheard of, but I just might to save my nice pistons and save $650 on a new set, since I'll be paying another $250 for a block and $400 for machine work. I'm not big on paying another $650 for a new block/machine work AND another $650 for pistons. FU@#$%^&

The only thing keeping me in this is that I sold my bike today and have $5000 in my wallet. Otherwise I would throw in the towel and walk away from this. Sell all my parts, both my cobras and just get out of mustangs. I am to that point. But I just need sleep and take another look at this tomorrow.

 

[Vipersix]

Calm yourself brother! There are two types of gear heads in this world, those who have gone through what you are now and those who will soon. Definitely take a breather and think things through carefully and as fully as possible. I jumped from one sporadic idea to another and now have an engine with something in excess of $20,000 invested but is worth half that. It's just one of those things we have to learn or deal with every time we get a hair-brained idea!

I agree with your assessment of the .060 over pistons (are you sure they didn't put smaller pistons in your block?), that is definitely an aggressive amount. However, Ross makes some great pistons and I would be more worried about excessive block wear than piston wear. Milling your pistons would be one option I suppose, but I would highly discourage that choice.

Here's my recommendation:

1) Sell what you can from this mess and consider whatever you come up short as a lesson in purchasing used parts. It is definitely a caveat emptor world out there for used parts.

2) Get yourself a roller block (they are not difficult to find anymore these days at most scrap yards). The $500 you would have needed to spend on new lifters will more than cover the cost of the new block and a good bit of the machine work depending on what you decide to have done to it.

3) Try to sell your pistons or do a swap for smaller ones. Depending on which brand you get, you're looking at anywhere from $200 to $800. I will agree that Ross makes some amazing pistons but they might be a bit overkill for your needs. I also highly recommend Probe and they come in about the middle as far as price is concerned.

It's always a bummer to know that you have more bills coming through the door when you were sure you were about ready to fire up your motor. I've built, torn down, and rebuilt my engine probably five or six times. If there is only one single piece of advice I could give it would be this: Make a complete list of exactly what you want to do with your car before you buy a single part and sit on that list for a week minimum in order to be satisfied that it is accurate. This will save you plenty of headaches down the road!

Good luck!

 

[fords2fast4u]

whew. you're right. I hadn't slept yesterday and it was a long day.

Still not sure where I'm at on the 94 build, but I'm guessing I'll drive my 93 around after some new rear end bushings and exhaust gaskets and think about it. I just don't think I have the time now to finish it (the 94) before i go back to NY, so time will only tell.

I'll probably take my time finding a roller 351 and then mag all the internals to make sure they're good, maybe try and find some smaller pistons too.

thanks for the advice! I've sure learned a lesson or two.

 

[fords2fast4u]

Some more info, in case you were hanging on the edge of your seat...

I've found out so much in breaking this engine apart.

At first I though that there were no marks on the pistons that match those scratches, so i thought for a while that these pistons had never been run in this motor... but after some more investigating, I did find a different kind of scratches that matched a piston and bore, telling me that they have in fact been run in this motor. Now the bearings are worn, but so little that I'd say this engine, or at least rotating assembly (or bearings in this motor) have very low miles... but the block, from taking various measurements, has many more miles on this bore... and the scratches are from a past build.

bottom line, someone knew the scratches were bad, tried to hone them (the bores are wider in those cylinders) but couldn't get them out. So they put it together, and didn't run it long (probably smoked or burned oil with those scratches) and then something broke, debris got in #2 and they took it apart, cleaned it, put some new heads on it and sold it.

the rod bolts weren't even tight (but the mains were and the oil pan was on). its such a good thing i took this apart to check it before just bolting stuff on. Who puts an oil pan on without tightening the rod bolts? the first clue told it all... the oil pan gasket sealer was all gunked on there, letting me know that whoever put this together, didn't know what they were doing. And in the end, that's still the case.

I found a guy who'll trade me my old cobra intake for a freshly machined roller 351W. I'll have the rotating assembly cheked, be able to use the cam and lifters (though I'll buy new lifters since i can't tell how many miles are on them) and be out about $650-$850, since I'll have it machined again to take my forged rotating assembly (if its all good after having it all mag'd).

some people.

 

[Vipersix]

Sounds like you've learned an invaluable lesson. Or at least experienced one; only time will tell if you have in fact learned from it!