Second shipment from TA Performance has arrived...just gotta go get it. Roller cam, SFI approved flexplate, new front cover with adjustable oil pump, and gaskets. Still no word from Scott about the pistons. (I'm guessing anther week or two.) Also waiting for the JW 9 1/2" converter. (Same...week or two) Will wait until everything is accounted for and then make a trip down to Montana.
Got a reply from Scott Brown on the pistons. He should get them tomorrow, so they should be shipped out in the next day or two.
Latest update on what seems to be the "Murphy's Law" engine build: -pistons were shipped with no pins, but Scott had them shipped faster then a speeding bullet! Absolutely AWESOME customer service from him. Service after the sale! Thank you Scott Brown! -shop finished honing the cylinders to the pistons. -shop installed main bearings, and crank, then the pistons on the four corners......here is where the **** hits the fan... -shop measures the piston to deck heights on the four corners...finds the front two pistons are 0.030"/0.031" down the holes...and the back two are....wait for it........0.041"/0.043" down the hole. Now first thing is when we ordered the pistons, we stated we wanted a compression height of 1.750", and Scott changed that to 1.725" I mentioned it in an email, saying that if he thought that was safer for the street, I trust him with his decision. (I believe his decision was based on a standard height block) So if our block was at minimum stock block height, we would have had the front two pistons down in the hole only 0.005"...and if the crank was ground correctly, all of them would be 0.005" down into the holes...but, the crank was ground progressively worse from front to back, ending at 0.012" off, on the last two throws. Here's more to the story...if you have followed along, you know that the crank went to another shop to be ground after the first shop could not get it done. (They took the crank over to the other shop, as they deal with them "all the time".) I can say for 110% certain, that if I try to go back to the shop that ground the crank, I will be told to take a flying leap at a donut. And there is no way I would trust them to do it right the second time either... I sent Sean a text explaining everything, and he called me to talk about it... We are faced with a couple options: -find another virgin crank, and have a quality shop stroke it for us. (We could gain even more stroke because it's a standard crank, and not a 0.010" under, like the one we used.) Or, -deck the block 0.020" on both sides, and 0.010" off the heads, and live with the 0.012" difference from front to back. (0.004" per cylinder) Compression would be 10.61 on the front two, 10.51 on the next, 10.41 and the back two would be 10.31:1 (As per Scotts measurements) Or, Skip the block machining, and just use steel head gaskets. (We are using head studs)
Don't use any crank that deviates more than .002" stroke, period. How you handle the aftermath of that debacle is up to you (I would have the shop source you a core, at least) A crank shop should have a stroke checker (custom V block with indicator for spot checking) or check from centers to verify. Do this before accepting the part. Maybe have someone trustworthy ship you a finished crank and the one that F'd up buy your crank back. If not done, make sure your block is decked parallel. Gotta pay to play.
Yes, to the mains. Looks like the shop used your crank as a setup piece! The second one would probably come out right.
Deck is within 0.001" front to back on both sides. It was 0.005" taller on one side, but they corrected it. Waiting to hear back from Sean about the crank he has squirrelled away, and if he knows a competent crank grinder that can do the work. Derek! Are you out there? What would you charge to find a crank, and offset grind it for us?
The shop had already done a line hone after the main studs were installed. They flipped the crank end for end, and the measurements followed the crank...so the crank is at fault. Like I said, there is absolutely no way I will take anything to either of the two shops ever again.
Ivan, Looks like Derek is off line, but I sent him an email for you, told him you may need some assistance! He may even have an already stroked crank of Andy's, that might be for sale.
Are you sure the deck is parallel to the mains? If the block is being measured with the factory machining then it could be off that far from the factory! Some Mopar engines from back in the day were up to .040" off from to back of the deck from the factory! Is the shop you are using able to measure the actual deck height? The best way is with a spacer the same diameter as the main bearing housing installed in the mains so that some of that diameter is reachable down in from the deck through a piston bore. I think I already know the answer from the above question being no. If they could measure the deck height you would of had them parallel cut the deck, have them measure it, then order the pistons to end up where they needed to be. The spacer I referenced above would be for there block decking mill so they can parallel mill the deck to the mains. If they don't have that for their machine, it gets more challenging to measure the deck height and impossible to square the deck to the mains without "mocking up the build" to measure the four corners. I would trust the crank's stroke for being more consistent than the uncut factory deck or even a cut deck from a shop that needs to "mock up the 4 corners" to be able to measure the deck height. If they "mocked up" to the reground factory crank to cut the deck to the first place and used 4 different factory rods and pistons that aren't held to today's standard tolerances could be why the deck is off .012"? Or if its the same on both sides they could of used the same 2 factory rods and pistons and stuck the same ones in the front and the same in the back? Either way, not an accurate way to do things. Another way to measure the deck height would be to use a depth micrometer that is from 8" to 9" because 10.188" - half the diameter of the housing bore diameter of 3.1875", which would be 10.188" - 1.59375" = 8.59425" is what it would measure from the top of the diameter to the deck if the deck height was the factory spec, which they're usually around +.030" or more. So take your set of depth micrometers and set the flat part to be as close to being on the center of the main saddle on a 45* angle as possible while measuring to the deck. Use a flat piece of metal to bridge across the bore diameter you chose to measure through to. Take that number and half the diameter of the housing bore and add them together, now subtract about .005" because the width of the mics make them sit up higher than the point that needs to be measured to because the bottom of the mics are flat and the main saddle is round. This should get you within plus or minus .003" and repeatable for all 4 corners! The better way would be to have someone that owns a lathe to make a diameter the same size as the main housing bore to bolt up in the main saddle and mic from the deck down to the top of the diameter. Have the 3.1875" diameter made at least 2 x the main saddle width so when bolted in it sticks out far enough to measure down to, probably 4" to 6" would be perfect. Would be even better if you could get that diameter as long as the crank to bolt in with all 5 mains to be able to measure down from all 4 corners would be the most accurate way should be able to measure within .0005" if your mics are good. Derek
I was here writing a reply. The machine used to grind the crank must really be worn out to not be able to hold the stroke from front to back! So how did they measure the deck height? Seems odd if they "parallel milled" the deck why did they order the pistons so short? With the rods you have and the pistons you ordered, you should of been able to order the pistons so they went all the way up to at least .005" in the hole. And Andy does have an extra crank but it is only a 3.975" stroke if that works for you? You would have to get a hold of Alec96 I think his avatar is here and ask if he wants to sell it. The guy that did Andy's cranks is semi retired and not doing any cranks bigger than a 4 cylinder unless its from a motorcycle. I have been waiting to see what Dave's new guy would charge to make a sbb stroker crank but I think Dave keeps forgetting to ask. I haven't really been in a hurry to find out either so not all Dave's fault but really haven't had a reason to make that a priority. Derek
Derek, They had measured the four corners for piston to deck height. Then they flipped the crank end for end, and checked them again, and the measurements were the same, only reversed. The two shops I was referring to in the earlier post was the original shop I took the crank to, and the shop it ended up at. The block height was measured at 10.200 something this afternoon. (I don't remember the exact number.) Scott Brown changed the CH from the 1.750" that we asked for, to 1.725" after he heard we had decked the block to square it up. The shop that suggested the CH of 1.750" gave a 0.005" safety....just to be safe. (So the pistons would be 0.005" down, if everything went perfect.) I think Scott may have assumed the block to be at factory spec of 10.187", and changed the CH to 1.725" The shop also installed all the pistons, and checked the heights to see if it was just the back two throws, or if it was a gradual increase in error...and it was. Front two are good, next two are 0.004", then 0.008" and the back two are 0.012". These measurements repeated when the crank was flipped around, only that they were now reversed....high at the back, and low at the front. (If it was the block, the measurements would not change when the crank was flipped end for end.)
Yes, if Scott didn't change the CH from 1.750" to 1.725", and the crank WAS ground straight, the pistons would have been 0.005" down in the hole. But because Scott changed the CH, the front two are down 0.030" Just read the email from Scott, and he based his calculations off of a deck height of 10.160" He usually goes by 10.170" but knew the block was decked 0.010" so he went with 10.160"
You don't let Scott decide what compression distance you need, you tell him after the machine shop measures your deck height! That way if he changes anything on you, he has to have them remade for you. I still don't understand why he changed what you ordered? You subtract the rod length and half of the stroke from the actual deck height and that would tell you what you would need to get to zero deck. Then if you wanted .005" more in the hole, you subtract that from the zero deck height dimension and there ya go. Where the flock is he getting his info from? All the reference material I have even found for the sbb 350 says it has a 10.188" or 10.187" deck height, even though most are around +.030" of that. So your actual deck height is 10.190" it looks like. Derek
Yes, I've seen a couple in which both ends don't center up along the same axis. I put a bid on one with that same problem a few years ago. The funny thing is to think about how they would have to dress the wheel to not see such a heavy taper when grinding. Even funnier is the damage that does to the local economy in regards to customer relations and trust. A bad shop can completely burn a marketplace.
Yeah, you just don't know how competent a shop is until you get something done from them. I'm sorry this isn't going as smooth as it should go up there in the Great White North. I helped someone else find to crank shop in San Antonio TX without hardly even trying that said they could grind a stroker crank. Of coarse the same thing applies with those shops as well, you don't know until you go. I have been spoiled working with Dave from Engine Craft all these years, I have him trained pretty good. Derek
Update: I called the crank grinder today, and explained what the other shop found. He naturally said no way it could happen, and started to explain how he sets up, etc. He then said he knew my shops manager, the guy I deal with, and that he would call him. The crank grinder called me back after about 10 minutes, and basically said, whatever you wanna do, let me know...if you want me to grind another crank for you, no problem. But I don't really want to try another crank with him. Because if it's something with his grinder/lathe...btw it's an old Strom or Storm unit, and my shop said he had the bed scraped about a year ago. (Whatever that means...) Spoke to my guy again afterwards, and he clarified a few things: -they used the same piston and rod on each cylinder when they measured the piston height on each hole initially. (Stock) -they used the same Nascar rod and tool they made up, to get the compression height for the custom pistons. -they used the same new piston, and Nascar rod to measured the heights afterwards on each hole. -they flipped the crank end for end, and again, used the same setup, and got the same measurements, only reversed. I spoke with Sean a lot today, and in the end, he sold me his virgin crank, and is taking it to a very reputable shop on Monday, and having it stroked. Hope it is perfect, and they can get even more stroke out of it. I spoke to the shop who is doing the work, and they said if it's dropped off Monday, you can pick it up on Friday, no problem. I asked what kind of machine they use, and he replied, it's a new Burko. (However its spelt) So, here is a huge Thank You! to Sean for helping us once again, and looking forward to meeting you next Friday.
Thanks for the kind words Ivan.... It is super cool to see a father son project so I will continue to do anything I can to help out!
