Thread: Has this ever happened to you?- "Freshen Up"

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Hello again all,
recently I happened across a 1990 Suburban with 454 for $1000. I figure since the Orange Frankensub is already setup for a BBC I'll swap it out and have a computer and TBI to go along with it. Easy enough. After all It's a running engine, I started it up before pulling it, but the rear main seal was leaking so I decided to replace that. Also I wanted to put an aftermarket intake on it, then the cam looked bad, then I thought I would just go ahead and swap out the main and rod bearing. Now the pistons and rods are in a box, the entire block is striped down and cleaned and this all started because I wanted to change out the rear main seal. So I ask, Has this ever happened to you?
Now I got some questions for you. I've only rebuilt 3 engines 2 BBC's and I always started with a freshly machined block I never just "freshened up" an engine. How far do I go with it? I mean everything looks pretty good considering the oil look so bad. I don't have a bore measuring tool but I can't feel any ridge in the cylinders for the most part with my bare fingers, maybe a little in 7 and 8.Can I just de-glaze the cylinders and re-ring it without going up 30 over or is that just really hokie? Do I get the crank ground down.010 or just plastigauge it and call it good if it's in spec? Another thing, I planned on putting a close to stock flat tappet hydraulic cam back in it to conform to the TBI computer but all this talk I have been reading about new oil and the phenomenal rate of BBC cam failures has really got me second guessing that. Is it really that hard to break in a BBC cam these days?
I've been reading alot of the past threads and haven't seen what I'm looking for so any input will be appreciate.

you need to spec everything. check the crank lobes for roundness, if there good, then just polish it.. you really need a dial bore gauge to determin if it needs bored out.. but a set of snap gauges and some extra time will do the same thing, and you won't need to spend a lot to get them.... putting it togther just guessing could be throwing money away if somthing is amiss.

you can get away with an awful lot , my first ever rebuild was a 454 in my dads 74 chev worktruck back in 1983, i was taking my mechanics training and took the motor in, it was burning oil and needed some tlc. i remember it had over 10 thou taper in the cylinders but crank was clean and pistons looked good. Our instructor at the time said it will work fine
took it and had it tanked put cam bearings and cam lifters timing chain in it hand honed the block used iron rings and standard bearings plasigauged and away it went. This motor lasted 18 years of dirt filled farm field use with little to no matinence except oil changes till the cam broke in half, probably 70 -80 thous miles and dozens of overheats
now i have a rebuildable 454 4 bolt block in my possesion that is still in pretty good shape.
I rebuilt my 500 cadillac last winter basicly the same way and hand honed the cylinders eyballed the piston clearances as they looked good had the crank cleaned up and rebuilt the heads. It has about 40 1/4 passes on it and about 600 hw miles on it and runs great. When i took this motor apart it was missing part of 1 of its rod bearings plus the lifters and cam were completly shot (best of 12.9s on this grenade)
Of course you can run into trouble by doing this as opposed to the proper measurements and procedures but sometimes as i said you can get away with a lot.

It may be a matter of how much money you want to spend and how much you can or want to do yourself. I’ve built my share of motors and big or small, there’s a few things that I always have done and then there’s a list of “optional” items that get done if the money and time permit.

Before you start, find a good local machine shop. You may already know one. Talk with the machinist that will be doing the work and tell him (or her) that you’re on a budget and would like to have an “ala-carte” approach that will allow you to pick-and-choose what you’ll have done. Work with the shop and buy the parts from them. Building a relationship with them will go along way towards a successful build.

At a minimum, I would recommend the following:
1. Take the block to a machine shop and have the block hot tanked. This gets all the glop off makes things a lot easier to work on. Having a clean base is a must for paint as well. You can have the shop measure all your clearances at this time and determine if a bore is required or if you can get by with a cylinder hone (which you can do yourself). The shop can also check the other “vitals” and determine if the mains are square as well as the deck.

2. Have the machine shop put in new cam bearings. You can decide if you able to put in new brass freeze plus and the oil galley plugs.

3. If you have a good micrometer, you can measure the crank. If you’re happy with the results, just get new standard size bearings. If not, you’ll need to have it turned and buy appropriately sized bearings. In that you’ve had this one running, you may well be able to reuse the crank “as-is” with new standard sized bearings. I’ve rebuilt engines with well over 100K miles and been able to use the crank without any work.

4. If your bores are good, inspect the pistons and if they’re decent, new rings and rod bearings will be the ticket. If not, new pistons and rings will be required. This can be a big ticket if you go fancy – Speed-Pro piston and ring kits are $250, JE and Keith Blacks can easily run $900 plus.

5. Your rods are probably okay. The stock 454 rods are really pretty tough to hurt as long as they have good oil. If you’re using the original piston, this is a “no-brainer”, keep the stock rods too.

6. Have your heads done at the machine shop. Talk to them and decide how much you want to invest and plan a course accordingly. Again, if you want to get fancy, you can drop a ton of money here. If possible and practical, have your shop do a good valve job, replace what’s necessary and call it good. If you have extra money – ask Pat McCarthy (on this site) to point you in the right direction or perhaps even build you a set. He is certainly the most knowledgeable on bi.g block Chevy engines.

7. Buy a good gasket set with all the seals. Your machine shop probably will cut you a good deal on FelPro or similar.

8. If you’re going to stay with a stock cam profile to keep the computer happy buy it (and new lifters) from your shop or NAPA. Buy a new, true roller timing set from the same place.

The rest is really straight forward. When you get the block home, scrub it really good with hot soapy water. I like Dawn (get you own so as to not tick off your lady!) Dry the block real good with compressed air and then paint everything that shows. Lube all the inside parts with a light coating of oil or assembly lube (don’t use WD-40).

If you don’t have an engine stand, get one. You can find them cheap (I’ve seen them for $59), but I would recommend one with four casters as they are a bit more stable with heavy motors. If you don’t have an assembly manual, buy one and follow the assembly procedures in the order. Of course this is also the time to add any "bolt-on bling-bling".

I would not worry about cam failure. Break it in slowly and as per any instructions that come with the cam. Use good oil and change is after a couple hours run time and look for any “tell-tale” signs, i.e, metal or water. Take your time and have fun.

Keep us informed as to your progress!

Regards,
Glenn

i built some big blocks i will not put a flat lifter cam in one no matter stock or races not just one thing but many and the first two on my list are no oil with zddp and not always there to make sure the cam is broken right i have been told after the fact of fresh engine getting crank over till the battery was dead and i have and fired up bbc engines watch everything go right fire right up and eat the cam or in a week or two .as for a rering job i do them .but there abit more to it .one point is just about any thing can run but how good and how long . bores are a big deal with me they need to be strait and round if not it needs a bore cast pistons work great to stock to mild builds and are cheap you may not see a lip at the top but there can be wear at bottom of the bore to so the bore can be worn past a rering the bores can be in so so shape but the pistons skirts can be worn you can tell this by looking at the shirts as well as ring lands can get worn and the ring will flop in the ring land groves a set of mics is handy a long with a good bore gages at lest a snap gage your engine has cast pistons in it they will not take a.004 piston to wall so at the lest use a feeler gage with your pistons take off rings and check it in the hole it came out of with a feeler gages and see what you have .002 would be great any thing past 003 is bad you will take some metal out with a hone your better with a ball type hone they give a good cross hatch with the lest amount of metal removal.on the heads bbc can be hard on valve guides this can be fix in many ways .i like to core them a put a 502 wall guides in mag bronzes or iron other then that they may not need much less crack or you have a burnt valve .on rods they are could be ok if not blue they should be check for size no matter what you do. so no need for a recon for stock use on the crank if it is in spec then get it polish and run it you can fit the crank if it on the low side by using a 001 rods or mains if needed .you would be far off to have the block dip or bake to get all junk out i hot tank or jet wash and put the cam bearings and i polish the crank i do not grind cranks less they are hurt or out of size .there many things i tell the customers were i will not not cut a corner. the deck and ring sealing long with a good valve job .i tell my customers that they will have time and money in to a re ring and not much more for a bore and new pistons if you buy a master kit .i cut the heads any ways after a valve job. if i long block there engine it will get deck it will get the rods re built with new bolts this better my chance and a roller cam .to just see you tell me how great it runs and nothing more

Thanks for the replies guys.

Well, I got a few things done. I used the ring and feeler gauge method to check the cylinders for taper and they're really not too bad. Five of them are around .0016 and the others about .0024. This doesn't tell me the actual bore size but my piston clearance is still closer to tight than not. The pistons look pretty good too. The skirts don't have any scuffs or signs of overheating but one piston had a broken ring and the grove is a little wide in one spot.
The crank looks good except for some scatches on the front and rear mains. The journals all measured up well within standard, round and without taper. I think I'll just polish it up and run it.
The heads are a done deal. I'm just pulling them off my other engine. They were just completely reworked with springs to match the cam and 3/8 guide plates.
When all is said and done I think I'm just gonna deglaze the cylinders, polish the crank and get it back together. I do feel a little better about it though now that I got some input as to what to look for, thanks again. Pat, you mentioned getting a good cross pattern from a bead hone. Is this better than using the stone honer? I read in one of these rebuild books to use the 220 stones very slowly for a good pattern. You think it'll take off too much material?

I would love to go with a roller cam but just can't swing the entire set up right now. I think this time around I will stick to the flat tappet and take some extra care in breaking it in. I think I read in a thread somewhere to use molly on the lobes, break in additive and zinc additive to the oil and lighten up the spring load by pulling out the 2nd spring. In a stock performance application like mine, how can you tell the cam is wasted? I mean performance wise where do you see it most?

OK lastly for now, why not WD40 on the block to keep the surface rust off after a bath? Does it break the oil down or something?

Thanks again for the input. It has helped alot.

roller cam kits are less then 700 with every thing as for a brm hone they work good but i have a AN sunnen i use then i bore 220 should be fine the one i have i think is 180 grit but i use a plateau hone after as for cams wiping i seen them go with moly on them and from mild cams to race cams