Cylinder wall scoring - bad news?

[landshark]

Not being an experienced engine guy i have a question or two about one i recently picked up.

The engine has been re-bored .30 over, cleaned up, new cam, timing chain, bearings etc.. upon inspection of the cylinder bores however there are vertical scratches... some are short, some are long.. most I cant feel with my fingernail however there are a few that are deep enough to catch my nail on.. I assume this is bad and will result in a smokey oily mess... I suspect the .30 over was done some time ago and it was recently honed.. which wont really help in the long run.

It does have TRW pistons and an RV Toquer cam (no idea on what kind yet)...

anyway I took a few pics and need some opinions from the knowledgable crowd out there... is this block a paperweight or will this be ok to run?

I plan on pulling the pan and inspecting the rest of it tomorrow night..

[airbur]

Look elsewhere. That thing should be spotless if it was just bored. Also, why did they put the old pistons back in? Is everything else in there used as well...rings, bearings etc ?

I'd just dump it or take it to a real machine shop and see what they can do.

[Viperwolf1]

It can be bored but might not clean up until .060" or more over. If any of the scratches are more than .015" deep consider it a boat anchor.

[landshark]

It can be bored but might not clean up until .060" or more over. If any of the scratches are more than .015" deep consider it a boat anchor.

thats what iam afraid of, i would be better off using or boring the motor that i originally pulled out of the truck and part this one out.. if i can...

iam in the process of tearing down the new engine completely to see what i have, i have a feeling there was some fudging going on in regards to the specs....

The timing chain seems like its new.. maybe even the lower gear. The oil pump looks new but not sure how to tell...

The pistons have B735 stamped on them and from my limited search it seems they are just kit aluminum pistons..

Iam going to pull the cam and try to ID it.. and pull the pistons as well and see if i can id them and see if the rings are used or what is going on...

Guess iam not going to be building up this block

[airbur]

If you know that the block that was in your rig hasn't been rebuilt....I'd start with that one. .030 is really as far as you want to go. Rebuild kits that include most all the internals can be had for around $300 from Summit and that includes new pistons etc.

[landshark]

yup we are going to recycle the block.. pulling the rest of it apart today to see what cam and other bits are useable...

[airbur]

Good plan. That 5th picture scares me....looks like they had sand in the oil. I wouldn't trust any internal part of that engine (including cam).

[landshark]

ya i will pull the cam and shoot some pics.. the timing chain looks new as does the oil pump.. and the cam has lots of goop on it.. like install stuff.. so who knows.. anyway i will post up later tonight.

[landshark]

alright pulled the rest of the engine apart...

looks like the timing chain and gear is new? There was NO play in the chain not even slight movement...




Pulled the cam, looks like a Comp Cam 260h, which i guess is ok if your running a close to stocker engine... i looked pretty close see no scratches or scars.. a few light scratches.. like very like.. can't feel them..





is there something in particular i should look for? its definitly been ran i can see the marks on the outter lobes.. but other than that it looks ok?

Pulled the crank next, looks like the races (if thats what you call them) look brand new...















picture of the crank...





then i pulled the pistons.. not sure if they are used or not.. rings look like they have never been ran.. wont bore you with images of all of them..













thoughts?

[ZOSO]

Measure the bore. Looks almost like they just pulled it apart and cleaned the pistons. Re ringed it with new bearings.

[landshark]

Measure the bore. Looks almost like they just pulled it apart and cleaned the pistons. Re ringed it with new bearings.

iam not using the block.. does it matter? iam going to probably use the cam timing chain, oil pick/pump and thats about it.

[airbur]

The oil pump is cheap.....don't chance it.

[Viperwolf1]

Looks almost like they just pulled it apart and cleaned the pistons. Re ringed it with new bearings.

My thought too.

[landshark]

so i could use the cam and timing chain in my 78 block then junk the rest?

I do plan on going EFI, either on my 78 block with exploder upper and serp or find a roller block and build that up with explorer upper and serp..

I have a Comp XE258HR cam and crane 1.6 roller rockers under my bench i have yet to use.. so might be fun to go roller..

[Viperwolf1]

so i could use the cam and timing chain in my 78 block then junk the rest?

Yes. That crankshaft looks like it's in good shape too.

[Booger]

A few things:
Don't leave the crank laying on it's side. Causes it to bend. Bolt the flywheel/flexplate to it and stand it up or leave it in the block supported by the mains.
If the cam is used and you reuse it did you mark which lifter went to which lobe? Can cause the lobes to go flat. Check the lifter surface with a straightedge and see if you see any dish to the lifters if so replace em.

Most pistons I've seen have the overbore size stamped on the top. Like Zoso said it might just have been honed and maybe new rings and bearings. Look at the back side of the bearings it should have a number like 10 or 010 or something if crank was turned.

I've run a few engines that we just removed the ridge at the top of the bore, new rings, bearings and seals (not new cam bearings), hone bores, clean pistons and go. Is it going to run 100k miles probably not but it will get from A to B. It'll run and might use a little oil but shouldn't be a mosquito fogger.

Now if your wanting to put it in the old Bronco check the bore and see if it's been bored. Some older engines could take more overbore than newer engines. Had a buddy in high school that bored his Buick somewhere around .100 over. Walls were thin but that thing ran like stink. Seems he bought pistons for a .030 425ci when his engine was a 401ci. Machine shop bored it out and they weren't sure how long it would last but it made it through a crazy high school kid who did a lot of street racing with it.

[Lila76]

Why are the pistons painted blue on top? That scoring is no bueno. Sorry man!

[landshark]

A few things:
Don't leave the crank laying on it's side. Causes it to bend. Bolt the flywheel/flexplate to it and stand it up or leave it in the block supported by the mains.

well iam going to toss the block i guess, and I dont have any extra flexplates/flywheels.. i guess i can pull one on my next JY run or figure out another way to mount it vertically. Not sure why i even need this crank, best to get rid of it?

If the cam is used and you reuse it did you mark which lifter went to which lobe? Can cause the lobes to go flat. Check the lifter surface with a straightedge and see if you see any dish to the lifters if so replace em.

I did not know that.. well i didn't mark them when i pulled em out... I will check the lifter surfaces and keep the ones that are good. I have another set out of the 78 302 I pulled out of my bronco as well...

Most pistons I've seen have the overbore size stamped on the top. Like Zoso said it might just have been honed and maybe new rings and bearings. Look at the back side of the bearings it should have a number like 10 or 010 or something if crank was turned.

there are .30 markings at the top of all the pistons. I think the engine was bored out previously.. then recently honed and a timing chain put in and he sold it.

I've run a few engines that we just removed the ridge at the top of the bore, new rings, bearings and seals (not new cam bearings), hone bores, clean pistons and go. Is it going to run 100k miles probably not but it will get from A to B. It'll run and might use a little oil but shouldn't be a mosquito fogger.

I'm going to probably toss he block anyway not sure about the pistons if they are any good or not.. rings look like they have never been run.

Now if your wanting to put it in the old Bronco check the bore and see if it's been bored. Some older engines could take more overbore than newer engines. Had a buddy in high school that bored his Buick somewhere around .100 over. Walls were thin but that thing ran like stink. Seems he bought pistons for a .030 425ci when his engine was a 401ci. Machine shop bored it out and they weren't sure how long it would last but it made it through a crazy high school kid who did a lot of street racing with it.

I think iam better off finding another block, maybe even a roller block. I have a few inquiries out now!

Thanks for all the info guys, more education is what i was looking for!

[landshark]

Why are the pistons painted blue on top? That scoring is no bueno. Sorry man!

I guess they left them in when they painted the block and were a little sloppy.. i know that will burn right off.. but the scoring.. well thats not going to work out.

[Viperwolf1]

Only reason to save the crankshaft is if it's better than the next one. It won't fit in a roller block though.

[landshark]

Only reason to save the crankshaft is if it's better than the next one. It won't fit in a roller block though.

yup figured.. ok i will save it.. i can find some room in my basement ;)

[Booger]

Chris about the cam and lifters - you would be better off just buying all new than keeping a few.