A tire spinning 10.8ET @ 125MPH. With the weight of the car & the MPH with good traction should really be somewhere around a 10.5-10.6ET. Of course like most others we're looking to go faster yet with the installation of the Hilborn set-up. Need to do some fine tuning yet before we can go out. But, may not go faster as Bob is in the mode of returning the car back to stock. Adding the side glass & ALL the mechanisms, heater, wipers, etc. Glad I talked him out of tubing it then it would have been much harder to return to stock.
I dropped off the block and crank at the machine shop a few weeks back and after discussing options we decided to oven clean the block, essentially baking the grease off and pressure testing the block for cracks. I also asked them to check the cylinder bore measurements and crank journals. The good news is that the block has no cracks and they believe the crank will clean up with a little polishing. In addition, they would not recommend aligning the mains as all looked good to them. The bad news is that the one cylinder I was questioning is going to need a .030" overbore to cleanup and even at that overbore they are not sure it will be right. They explained that there is one spot in the cylinder which is causing the issue. I asked for the measurements, but they had not written them down. They will recheck and get me the measurements. They felt that there was possibly a broken ring in that cylinder. That is the only cylinder which had a broken ring when I removed the piston. I thought I broke the ring removing the piston as that cylinder had the biggest ridge. All the other rings on all cylinders came out whole. They felt all of the other cylinders would easily cleanup with .020" overbore. The mentioned they saw standard replacement pistons up to .060", but recommended we install a sleeve in the one cylinder and bore everything over .020". The cost of the sleeve install would be $83 plus the cost of the sleeve. I have never had to sleeve a block before and am a little uncomfortable with the idea. I know it is common practice, but for some reason I would rather not go down that path unless it is the last resort. I could look for another block, but this is the numbers matching block for the car. Although I am not doing a stock rebuild, I would like to maintain the numbers matching status for resale reasons. As an alternative I asked if they could sonic test all of the cylinders to see if we could go over .030" on all cylinders; to avoid sleeving the one cylinder. I am ordering custom pistons, so I assume I could get whatever size I need, even if it is not a standard replacement size. I also plan on filling the water jackets up to the freeze plugs which will add more strength when I bore it. I assume I might still end up with the sleeve option if the sonic testing does not prove there is enough meat on the cylinders. What do you all think? Should I just go with the recommended sleeve? Is my sleeve-a-phobia ridiculous? Anyone know how much a sleeve costs? Thanks
I would keep the bore as small as possible,, sleeve the cyl.... and go on building the engine.....:Brow: :Brow:
Thanks Doc, I always thought of sleeving as a last resort. So it would be better to sleeve and not unnecessarily bore the remaining cylinders larger?
That's what I thought too. Boring is cheaper, at least if you have to do 8 cylinders. If one cylinder had to go 0.040"+, and the others were ok at 0.030", then I might consider sleeving one. I'd suggest going 0.030" on all of them if the sonic test results are good AND that troublesome cylinder will clean up at 0.030"
In my younger days, I didn't think anything at all about milling heads or boring engines the max at the first rattle out of the box.... ou: but,,, then I decided that engines and nailhead engines are not getting more plentifull.... so it is best to make them last as long as possible... lets face it a head can only be milled so many times, and a block can be bored just so many times.... :Smarty: so in the interest of making things last ,,,, I do the minimum,,, that will clean up... back in the 60's we would do ''blueprint '' machining,,, but,,, I soon realised that ,, that approach was for all out competition... not street cars.... :Brow:
Walt, I think that is the problem. The machine shop is not sure the bad cylinder will clean up at .030". My thought was if .040" would do it and the sonic check showed enough meat on all cylinders to go .040" then that would be the option I went with. I am ordering custom forged pistons anyway, so I assumed I can get them at .040". My sense was that this was a better option then sleeving the one cylinder and going .020" on all, but now I am wavering based on Doc's advice, as I do agree removing as little metal as possible is a good option. For some reason I am hung up on the thought of sleeving a cylinder.
Our engine dropped a valve and broke a piston. During the rebuild the cylinder with broken piston got sleeved. We've had zero problems with the sleeve since. Oh, and all this happened in 1975, 36 years ago!! My vote: Sleeve It!:TU: :TU:
Only problem I see at .040" over is rings. There is a gap with 5/64" rings & 1/16" rings availability. The gap is from 4.22", an overbore of .030" on a 401, and 4.250". I have had good luck/results boring to 4.250" but I filled the block with Epoxy higher than the bottom of the big freeze plugs on the side. The last .040"/401 I did I had to have Hastings make the rings. .030" rings had a ring end gap of .040"+. Yeah, I know they make oversize pistons at .040"-.060" but the oversize rings aren't off the shelf ready. Just something else to ponder. Tom T.
Thanks Tom, I did not even consider ring availability. After reading all these posts, I am convinced that the sleeve is the right direction. Anyone know the average cost of a sleeve for a 401, I could not find anything online? If I sleeve the one cylinder and bore all cylinders to .020" will I have any issue with finding a set of rings or should I go out to .030", since parts would be more readily available? In addition, if I go out .030" should I sonic check the other cylinders; I was not planning on this step at 0.20". Thanks
Go 0.040" or sleeve one for 0.020??? ...Flip a coin! Nice to have some extra metal in case a repair is needed in the future. A Moper 413 shares the Buick 401's 4 3/16" bore size.... an eBay search shows rings avail in 020, 030, 040, 060 from Hastings.... better verify what's on the shelf! I went with 0.020" over on my last build with Hastings moly rings. Full listing of rings by bore size here: http://www.hastingsmfg.com/RingFinderIndividualRings.aspx Tom, is it worth using narrower rings for performance use? (custom pistons) That seems to be the trend... less tension and drag = more hp.
These are the 0.020" rings I used: Hastings # 2M437 http://www.ebay.com/itm/Dodge-Chrys...Parts_Accessories&vxp=mtr&hash=item4cfd265657
Thanks Walt Since rings at .020" are available, I am going to go with the theory of removing as little metal as possible and sleeve and bore to .020". Since I am planning on filling the water jackets up to the freeze plugs, should this be done before the sleeve or after? I know no boring should occur until after the fill, but was not sure how the sleeve fits into the steps. I am also going to skip on the sonic testing as it does not appear necessary at .020"; plus I can use that money for the cost of sleeving Thanks to all for the advice
In many instances sonic testing only costs between $75.00-$125.00 depending on who you use/find. This ring availability has the same gap for metric rings also even if you are having custom made pistons. Who will you be using for pistons??? For the added insurance & just to know I would perform this testing, then you KNOW. Yes, thinner rings make for more HP because of less "Drag". Years back the way to go was 1/16th. top 1/16th. second & 1/8th. oil. Today much is now metric. Also ALL rings can be low drag. Metric rings are available in 2mm, 1.5mm, 1mm, etc. Most all use 3/16ths. for oil control. Stocker type rebuilds I would use 1/16th. at .0625" or 1.5mm at .0595". These are just my opinion. Others may vary for any number of reasons. Install the sleeve, bolt in & torque mains, then add filler, then bore. Make SURE the sleeve has a step top & bottom to hold in place or pin it. Don't ask how I & the machine shop know. This shop had been around for a LONG time & knew what they were doing. It can & DOES happen. Been there, done that. I would rather take the precaution now than have the sleeve move with the resulting carnage. Tom T.
Thanks Tom Not sure what you mean by step top and bottom. I have seen sleeves with a flange at the top, which I thought kept the sleeve in place. With the top flange the sleeve can't move down and the head resting on the flange keeps it from moving up. Do you mean leave a step at the bottom of the cylinder for the sleeve to rest on; wouldn't this do the same as the flange at the top? And I have not heard of pinning the sleeve.
Repair sleeves are not flanged they require a machined step at the bottom of the bore to install against and the top of the sleeve is then machined off flush to deck pretty much a standard machine shop operation just pay and go.Done every day at a reputable shop.They are sold by size not application specific. W
After boring for the sleeve the bottom part of the block gets VERY THIN. Just a step at the bottom & it will break off. Look down there & you will see what I'm talking about. The boring has to be done to enlarge so that the sleeve has kind of press fit. Don't forget the sleeve will be at least 1/16th. inch thick & then you are going to bore that to the proper size needed. Having a step at the top also is just ADDED INSURANCE. It's up to you to do with the advice given. Don't forget, I'VE BEEN THERE & DONE THAT.
