Piston progress and questions

[NE57]

Just double checking if I did the right thing installing the pistons.

The Ross pistons come with a laser mic report so you know the exact sizes and relative sizes. While the differences between the pistons was miniscule(I think the range was .0005"), the cylinders I can't be as certain about their sizes, I'm not very experienced with the bore gauge so i could make a small mistake here or there. What I did was starting with the smallest piston, fit it in each bore with a feeler gauge (.004") and see which cylinder gave the best feel. then proceeded with the next larger piston etc. There was a definite difference in feel at times(large piston in a small bore for example) but the end result is essentially all pistons/cylinders now have about the same feel with the gauge inserted. The pistons varied slightly, I assume the cylinders did too since in the end they are all at .004"

The rings I had already gap measured and marked for their respective bores, I just matched up the groupings.

The shop had balanced the whole assembly, since the pistons were not marked by them I assume they use an average weight? The Ross report says they were all within (I think) 2 grams. I don't know how close the weights have to be. So I haven't screwed up the balance by doing this?

Rod side clearances are on the money. Feeler gauge results were very close to measuring rod pairs and journal widths.

But another question while I'm at it. I read that studs/bolts should be torqued and unbolted and retorqued several for the best tension. Is this true?

Thanks

[George]

Head bolts, main bolts, ect should be tightend in increments( I go 3rds). After running head bolts are usually retorqued(NOT UNBOLTED!).

[NE57]

For a minute there I thought I must have confused the 1/3 increment torque with the number of times to torque the bolts. I was pretty sure I read to do it several times so I snooped around and finally found this at the ARP site....

1. The friction factor changes from one application to the next. That is, the friction is at its highest value when the fastener is first tightened. Each additional time the fastener is torqued and loosened, this value gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, new fasteners should be tightened and loosened through several cycles before applying final torque. The number of times depends on the lubricant. For all situations where ARP lubricants are used, five cycles are required before final torquing.

I'm only guessing but maybe the contact surfaces(threads and nut face) slowly get polished by cycling in this way?

Being that I have ARP main studs and rod bolts, I think I'll play it safe, buy their lube and do it over their way.

[DHEMI]

My ROSS pistons were marked on the pin boss A-B-C etc.I think reccomended clearance
is .005 so you're close.

[budmspeeco]

Glad to see you making REAL progress!The Arp lube should have come with the hardware unless you bought them outside normal retail outlets. And I don't quite understand your concern about messing the balance up. Because you file fitted the rings? Imagine the massive weight of the particles you filed off one ring set versus another. Huge? If you have worries, take them back to the machine shop & have each set weighed. They should have at least weighed one set for a balance #. See if that # matches the one used to balance the rotating assembly. Printouts should have been given for each component's targeted weight , one complete individual cylinder set added together to get the bob weight. That would be a piston, pin, rod, retainer clips, one ring set of top/middle/oil ring pack, rod bearing set (pair). I have read of REAL nit pickers adding a minute amount for the oil on the crank while the motor was running. You will also see if there is a discernible difference in the individual ring sets, although I doubt they have a scale to measure that small of an amount. They should have numbered each piston to each cylinder it was to go in. Keep trying to just take single steps forward and not two back worrying about non existent problems. Again. As for the other problem of the valves/retainers/rockers hitting the covers, I saw a photo a few weeks ago somewhere that showed small rectangular pieces of aluminum welded to the outside of a set of early hemi valve covers. They were in the exact location where contact would be on the inside & you instantly came to mind!! I am assuming( BIG word) a machined amount of clearance was cut on the inside to prevent long valves/retainers/rockers from hitting the covers. The new hole, or at least , a very thin section, was reinforced with that plate.Seems like an easy fix unless you would be squeamish about cutting/welding on a nice set of valve covers. I personally have a set of early Donovans with the "HEADS AND VALVES" inscribed above "DONOVAN ENGR". It would be almost impossible for me to cut or weld on them without a huge fear factor of ruining them. I sold them on eBay for $1,250.00 but bought them back when the guy ran out of money. I was told they were made only to give to racers sponsored by Donovan in the 60s & 70s but never sold in that configuration. Keep up the good work!! Congratulations is also given when deserved and not just criticism. Buddy

[NE57]

What I meant by balance was this. The pistons were marked from Ross as ABCD etc. I didn't know if the shop would machine a specific bore for a specific piston as in A for #1 cyl, B for #2 and balace in the same way etc. Since there was a minimal weight difference would assembling something like A in #4 cyl, B in #1 cyl etc make an real difference in the balance overall.
Eventually I just fit each piston to each cylinder based in clearance. They all now have pretty close to the same clearance. Had I done it by A=#1, B=#2 etc, i would have a couple cyls on the low end and a couple on the high end of tolerances. I guessed that 2 grams may be within tolerance, balance wise, since a 2grm diff seemed to be within Ross's tolerances. i also guessed that the shop would have weighed ONE set and used that for each journal(well 2x actually). Hope I did it right.
While the pistons are in, if anyone thinks I made a major boo-boo I can still rearrange the piston/cylinder pairings.

I've pretty much given up on getting the motor in the car for this year. What with one thing and another my hoped for schedule went to hell. At this point I'll be happy enough if i get the motor running on a stand before winter and dry dock it til spring. Maybe by then I'll be moved into a bigger house with GASP! a two car garage! She can have her fancy kitchen i want a nice garage.

[budmspeeco]

All the machine shops I deal with mark the pistons 1 through 8. They then bore each cylinder to each corresponding numbered piston for that hole. This has NOTHING to do with balancing. The external sizes are only measured without any machining to remove material. Then each piston is weighed. The lightest number is found & the rest are machined INTERNALLY to match that number. Same for the rods. All the small ends are weighed, them machined/ ground until the small ends all weigh the same as the lightest one. Then each rod is weighed. The weight of the lightest is noted & the rest are machined/ground on the BIG end until they all weigh the same. Now all the pistons weigh the same & all the rods weigh the same. One rod, one piston, one ring set, one pair of bearings, a pair of retainer clips on floating pistons, and one pin ( they are checked but generally come within a fraction of a gram so no work is needed ) for the bob weight.. As I said before, the file fitting changes the weight only a fraction of a gram so that is not factored in the weights. I would check with the machine shop to see where A through H fit. If it differs from where you put them, verify the numbers with the shop by taking it back. Let them measure each piston to see that it is in the correct hole for correct clearances. A lot of work, but they should want to show they did it correctly without hesitation. Ross will give a +/- tolerance for clearance, usually about .0005. If you are still not satisfied take it elsewhere to have another shop check. The second will probably charge at least an hour but peace of mind is priceless. Do not switch the ring sets from the hole where you file fitted it. If you already put them in a wrong piston hole take them off & reinstall correctly. If any cylinder needs to be honed more than an additional .0005th, you will have to get another ring set for that cylinder. An additional .001 changes the gap about .0045 t0 .005 , actually .005113, on a 4.03 bore. .005 over individual sets are available. If you can't find them I will help. If any holes are too big for the pistons, you are screwed, blued, & tatood!!! A set that is bigger will need to be purchased. Buddy