paul "60s Style" brought his rat motor up last week, he had some water get into the oil and it was starting to cause some problems. I knew he was wanting to get it to the GG drags in july so i told him to bring it up to the "little shop of horrors" and we would see if we couldnt get it straightened out. i was curious as to why the water had caused so much of a problem so fast, it seemed that Paul found the problem and corrected it in no time, i knew that this engine had very little time on it since the build last year upon tearing the motor down we started noticing some things that werent right, and it soon became evident that some critical steps had been overlooked in the build i do not know who built the engine, and am not here to slam anybody, but Paul and i talked on the phone and decided to chronicle the rebuild here on the HAMB. in hopes that maybe somone getting ready to rebuild, or have machine work done would not have the problems arise that Paul did. RAFFLE NEWS for everyone who has e-mailed or pm'd about a HAMB drags raffle motor this year: YES, it will be a small block ford, a '68 302 block , using a cherry set of 289 rods and crank i came across. using the 302 block gives a little more cylinder wall down into the block, and will also give us a 6 bolt bell housing bolt pattern- much easier on ****** selection. as soon as Paul's engine is out it becomes number 1 priority. i still need to find a cool induction system and some heads but i am confident that will happen soon. i am personally gonna drive the ****er out to MOKAN in august. now back to our scheduled rebuild.............. the first thing we noticed was that even tho the rods were clearly marked with numbers they were in competely different cylinders than there stampings, this is not completely unheard of in a balanced rotating ***embly, but does show a lack of attention to detail the bearings also showed that they had made contact with the crank upon measuring the mains and rods it was evident that the clearances were way to tight. with the contamination of the oil with water the crank and bearings had made contact wiping out the bearing overlay.not only were they way to tight but the bearing crush did not look right. in the previous build ARP fastners had been installed, both rod bolts and main cap bolts were used. very good stuff, but when you change fastners you need to check the sizing of the rods and the alignment of the main caps. HAVE THIS CHECKED! we found the mainline to be off and the big ends of the rods were not correct, a simple align hone on the main caps and a resizing of the big ends on the rods and we were golden this will bring our bearing clearances back into spec,and bearing crush will be corrected another problem area was the hone, they had installed moly rings but the honing pattern did not look correct for the moly ring,also it was evident that the top ring had not seated, and the second ring was doing all the work, we were able to hone it and still retain proper piston to wall clearance, one hurdle jumped all the bearing material that went thru the motor had attacked the crank, but a polish brought it back nicely, this was great news as this crank had already been turned, was a forged unit, and part of the balanced ***embly. the block was tanked,all oil plugs and freeze plugs pulled,everything flushed out, magnafluxed, new plugs and freeze plugs installed, align honed and honed for moly ring,and the connecting rods resized today i started deburing the block, removing all the casting flash. big block chevys tend to have a lot of this in the valley area, you want to keep it from breaking off or becoming a stress riser and potential crack. it was then ****oned up for tonight, tomorrow it will get washed down and cleaned prior to the start of ***embly more in a day or so
*****in! [ QUOTE ] but when you change fastners you need to check the sizing of the rods and the alignment of the main caps. HAVE THIS CHECKED! [/ QUOTE ] Sizing of the rods??? as in, how wide the big ends are? Were the rods replaced, or the sides milled? Or just re-bored? Thanks, J
Burndup, the big ends were resized, the bolts are also the aligning dowels for the caps. when you change the bolts you usually change the alignment of the cap slightly. same thing on the main bearing caps, if you change the bolts or add studs instead of bolts, you more than likely will change the alignment of the caps.resizing the big ends of the rods and align honing the mains will bring the diameters and alignments back into spec
So exactly what machining gets done to the big ends of the rods to compensate for the caps being offset?
Nice post! Im diggin it. I can't wait for more. The cool thin is you are giving 60's a really cool rebuild s****book of sorts. With his posts and yours on his engine he and the rest of us have a reasonably complete car build. It gives me a good reference point to look at when and where things in the timeline ned to happen.
[ QUOTE ] So exactly what machining gets done to the big ends of the rods to compensate for the caps being offset? [/ QUOTE ] The rods need to be resized AFTER the bolts are changed.
sorry burndup a small amount of material is machined off the cap at the parting line surface. this causes the big end to be out of round when the cap is bolted back up to the rod, it is the same distance across the parting line,but is smaller vertical to the parting line. it is then honed out with a honed designed for this purpose, you will usually do two rods at a time as this helps keep them sqaure in the honing fixture.
Hey! Good stuff on BOTH accounts! First, it looks like Paul will have a properly built Rat motor back in his ride real soon, AND...this year's raffle engine will be a FORD! Great post, Racefab...being one who has purchased a poorly rebuilt engine in the past myself, I can relate to the headaches it causes down the line for the dude who has to FIX it!! Can't wait to see that hot small block FORD, either!!
EXCELLENT tech session. You mention the hone pattern not being correct for the moly rings. What is the difference between the pattern and finish for moly rings versus iron? When doing this at home, what stones would you recommend for the moly vs cast iron rings and could you advise on technique to achieve the best finish. Thanx.
I hate this post!!!! I am now freaking out because I just went through my 289 and put ARP rod bolts and Main Cap bolts in. I figured it was a "bolt-in" deal. Should I pull it apart again and have the caps sized and the line bore done??? I pulled it apart to check things as it was fresh (5,000 mile) rebuild that ran great. I thought the ARP hardware was a good idea while I had it apart. Now I'm not so sure!!!!
Racefab, your work makes me wish I had about 10 grand to send to you along with my 401 nailhead to have all kinds of neat good stuff done to it.
30 tudor; the hone for a moly ring is much smoother and not as "deep"of a cross hatch pattern. if i am doing it at home, say to freshen one up,i use a three stone glaze breaker style hone and use 400 grit. if i were doing a cast ring i would use arond a 260 grit. because i had this into the machine shop to do the mainline, i had them hone it with a torque plate, which distorts the block the same as if a head was bolted on. i really recommend if someone is going to change over to a moly ring,have a machine shop do the hone. born2late= if you had the bolts in the rods changed at a machine shop,i am sure they checked the big ends,and resized if needed. if you use the BFH system yourself at home i would be concerned. like i said before if you change the fasteners on the main caps you should have the align checked. fraz- 10 grand? you must be building a twin mill today i did some cleanup on the motor, and started getting ready for ***embly first i rolled the block outside and scrubbed it inside and out with hot soapy water,i did not get any pics of this as it was raining like hell. as i was cleaning the block , the pistons and rods were getting a good cleaning WARNING,you may want to wait till the wife is shopping before doing the rods and pistons after the block was scrubbed and rinsed, it was moved back inside and blown dry with compressed air looks nice and clean huh? i then take a clean white rag and pour on a little ****** fluid which shows it is not as clean as it looks! i keep wiping out the cylinders with clean rags and trans fluid till they come out looking like they went in after getting all the cylinders cleaned, i spray the entire block down with a protective oil then it is bagged and will only be removed when worked upon. it is at this point where i will no longer be doing any grinding or sanding in the shop until the motor is done, you can not keep the componets to clean when you are in ***embly phase more tomorrow
man Fred, that looks sweet! can we get some numbers? .010 over on the mains, .020 on the rod journals, .030 on the pistons right? and what were the numbers on the cam again? did you get a cc on the heads yet, the hypereutectic(sp) pistons have a slight dome to them, what kind of volume do they displace? that kind of stuff would be interesting to discuss.. maybe even a geuss at expected horsepower and torque, just to let the compe***ion know what they're up against Paul
man i hate crowds, graduations, weddings ,seems everybody figures June is the month,if there is a crowd you can find me standing in the back or outside somewhere got home a little late friday night from some graduation festivities, needed to find some alone time .headed out to the shop turned on the tunes, and emerged early sat morn with this 461 cubic inches of solid shortblock here is how i got there i lined up all my parts.in the back you will see a grease board i write all my specs on, i do this for whatever motor i am working on at the time. a quick glance over and i can see the spec or number i am looking for i started by mocking everthing up with bearings and taking measurements .i then measured the crank and figure the oil clearances, this thing has a healthy .002 oil clearance, instead of the very tight less than .001 that it had when it came in the same thing could have been done with plasti gauge, but this way i only put the crank in when i am ready to install it i laid the bearings in and put a coat of moly base ***embly lube on them, i lightly oiled then installed the rear main seal slightly off center so the parting line wouldnt line up with the parting line on the block/cap i then layed the crank in and did the same with the bearings in the main caps. also off setting the seal in the cap to match the block one i use the ***embly lube because it gives me a better cushion between the crank and bearings while i am ***embling the motor . the motor will be pre oiled prior to fireing it next is the rings on the pistons. lots of guys ask me how can i be sure the rings are in the right place when i am installing the piston. most rebuild manuals have a picture of where the end gaps go. just write it on the top of the piston with a sharpie for quick reference while installing i use 1 for top ring 2 for second ring r for oil ring rails e for oil ring expander i then install a bearing into the rod ,oil up the cylinder wall, oil the rings ,and install the ring compressor.i like the pliers type as i feel it gives me a little better control installing the piston. i had checked the end gaps on the rings the day before and installed them on the pistons, all i had to do today was set the gaps in the right locations and install i then install the rod cap and bearing and torque to spec. i use a stretch gauge, but a torque wrench is fine if you keep the threads clean and use the right lube .these were arp bolts so i used their lube and stretched to their specs now repeat 7 more times the wife came in and snapped a pic as i was sending the last piston /rod ***embly home we now have a very solid short block, i checked the deck height measurements,and started ccing the heads, rough calculations are looking some where around 9.1 maybe a little less i will take some hard numbers tommorrow and start playing with cam senarios on the dyno simulator should have longblock ready to go by the end of the week paul, will spend the next couple of days on the heads
The Jalopy Journal
