josh817 Posted April 25, 2008 Share Posted April 25, 2008 Well the deed has been set in stone. My initial spendings have been placed and the turbo setup has been sold for the most part (I admit I'll miss it). My plans were to rebuild a dying motor but I only had $700 to work with. Forged pistons, bearings, gasket sets, blah blah blah weren't within my range. I had the MS built but not installed. A guy down in Houston offered to install it and have it tuned in a weekend, and while doing so he could put proper piping and wiring in. Yet another expense. But then I got to thinking about it and here in Keller, Texas V8's are popular, turbo's are popular, but a stroker? Nah. I had bought the Z wanting a unique first car, no Honda Delsol for me, no Corvette, I wanted something that would stand out in the school parking lot, even though I'm not sure that was the brightest idea... So onwards with being unique and having a limited budget! Strokers aren't cheap apparently but I have the luxury of my dad owning a shop. He has just about any tool you can think of and the inventory is still growing even after 20+ years. He's an "exracer", did Triumph endurance racing across the country and then went to strictly Spitfire in a sprint racing club (Corinthian Racing). He has a lot of experience, a lot of knowledge and trick things to do to motors, and he isn't racing anymore as of now (has a 1932 Midget, aka death capsule) so he builds race motors and does restorations for the Triumph guys. Luckily Triumph isn't the most reliable engineering so he keeps himself within only 15 customers I'm betting which always come back to get something else done. Having that said I will learn and perform a lot of the machine work myself and before you snuff out the idea as a bad one I think its important to learn how everything is built and not to rely on others. Plus Dad will be standing over my side to say (yah you FUBR'd that one dude...) My plans: -F54 block bored to 89mm (I hate it being 3.1 but 3.2 with 90mm I read may have potential problems with cylinder walls) -P90 head ported/polished up to the gasket (by me) -KA24E dished pistons -L24 rods that are balanced (by me) I don't have the money to balance the entire rotating assembly but its only a street application so I figured half balanced is fine. Then again, I think balancing is either all or nothing so half doesn't count... -V07 crank -10LB flywheel -MSA Stage IV cam (.495/.290) -6-1 headers -3" exhaust -Choice between .6mm X 91mm, 1mm X 90mm, 2mm X 90mm head gasket -Triple Weber's 40mm I've been told will be fine I thought I was going to need 45's but seeing the price of them I was planning on doing 6 Mikuni bike carbs. Then again... College would be a good option next year rather than drooling over some shiny carbs. -Narrow band to help get me in the general area for carb tuning -MSD This should yield a 10.23:1 CR and I could careless about having to use premium because 10 cents is only ten cents to my teenage mind. This will reveal some of the power that the cam should make. I feel 11-12:1 would be better to open her up but only a street app... and one I would like to last for 5 years or more. I'm looking for power above 3000RPM and no more than 7000RPM. I don't want a smal cam to give me some "Streetable" power. If I need power, I won't be in the lower RPM's anyways but because this is only semi balanced and its a road going car I don't want to linger around 8000 RPM. With the Holset turbo and no tuning, basically just slapped together @ 12psi it threw me back into my seat and made my day while scaring Dad. The dude in Houston said that because of no MS and no tune, I was probably doing in the 200-250HP range, thus my stroker motor needs to have at least that much power to make me cry tears of joy. Same power - wiring/vacuum mess - turbo theology = happy Josh. Now for the stuff that will occur while the car is sitting. I have to set my priorities straight and 1st thing is the motor, 2nd things that will make the car presentable, 3rd things that are cool. Presentables: -Need to fix torn steering rack boots -Mount rear spoiler -Rustoleum paint the car (don't need any feedback on that decission...) -New tires but I have new wheels too so I'll throw those on -Strip out interior and paint truck bed liner in it (we're doing this for my BMW 2002 track car) -While doing the interior fix all lights inside IE: Ebrake light on speedo, stupid little stuff that bugs me -Fix the clunk in the rear before I put a potential HP beast back into it -Broken key in drivers door, 1 key for locks and another for ignition. If any of you dudes know how to pull a broken key in a lock do share rather than me getting a matching lock set. -Fix slight drip from tranny which just pisses me off every time I think I've fixed it. Cool stuff: -Suspension -The list can go on forever, you all know this. I think I'm on the right course. I have my expectations for the motor, what I need to buy, priorities, and spirit to build this thing. The only thing that keeps me going is A: avoid looking at the total cost of everything I put on this car, B: when in the situation of only lent being present in my pockets remember, its only money, and if you don't do it now and you choose to do it in 10 years or something that, the American dollar is going to bend you over and do dirty unmentionable things to you as it will be worth... well.. nothing. Or so it seems. This is more of a learning experience than anything. I've built motors before but only on the sidelines with Dad when I was younger. This is now MY project and the outcome of it will be solely dependent on the quality of MY decisions. Basically, if it kicks ass I will have the pride of saying I did that when I was 17. Even if it doesn't, I will still be prideful. And finally, I am building this car to be as close to track spec as possible while still being legal. As I posted in a previous thread, I am not building this car to enjoy luxuries, I am building it to drive. Damn the A/C, the heater, comfy seats, and being able to hear the radio. If I wanted that stuff I will drive my moms Civic. I'm a true believer on the connection between car and driver but I am like an old 60's F1 racer. I will adjust to the car, not the car to me. If its to loud, get out or get over it. Too hot, shut up and roll your window down even though here in Texas it just makes a convection oven. I get too much slack from people at school saying it needs paint, its loud blah blah blah. You will enjoy you SUV with a DVD player in the back while I will enjoy my well oiled performance man machine. Quote Link to comment Share on other sites More sharing options...
josh817 Posted April 25, 2008 Author Share Posted April 25, 2008 Alright so enough spiritual wisdom talk. Lets get down to business. Any time I do a big improvement, I will post pictures. This is kind of like my diary of events. I will share my progress, business transactions, and business men with you. I want a collection of picture of me with Jose and Bob who do my machine work (not real names), and maybe some video but I only have a camera not a camcorder. Day 1: NOTES: -Satan made wiring, Jesus saved us by creating the wire tuck idea -Tear out wiring anyways -Fix radiator overflow bottle so you don't look poor, because you are -Get more tools, you are very limited -LABEL AND BAG EVERYTHING, you are clumsy -Its ok if your Z Baby is a shelf for now Tomorrow (Friday) I'm going to a swap meet at TMS. One of th biggest in the nation so if you're in North Texas go take a gander. Saturday I will tear down the motor and prepare everything for the machine shop. More pictures will come then. Quote Link to comment Share on other sites More sharing options...
josh817 Posted April 27, 2008 Author Share Posted April 27, 2008 Just came back from the shop. Kind of disappointing. Dad didn't want to give over the engine stand because it has some dudes freshened Detamaso tranny on it which has been there for several months now. It already has been cleaned and serviced and he said the dude is coming to pick it up, a month ago. So basically I had to do my duties on the floor. Took all those horrible things which scavenge the outside of the motor off and jumped into the head. Some surprising things happened then: Head bolts were tighter than hell, had to use a breaker bar with a 3' extension. I thought you only torqued those down to 60-80ftlbs... Same thing happened with the old L24 block but that had collected rust. THEN I went to take the cam sprocket off and its the same way. It was so tight that I broke Dad's Craftsman 19mm socket. Luckily you get a free one if that happens. I'll just leave that for Rick, the machine shop guy before I mess anything else up. So I had to go through the timing cover and thats a whole new escapade of events, being held in with 50 bolds and all... I was also surprised that I didn't have a hole in one of my pistons. I was running lean on 13psi a long time ago, and new I had a compression problems afterwards, plus it burned through oil which is what prompted me to do this. The rings are probably owned though, you could tell it was definitely lean because of the spark plugs being white. NOTES: -If anyone has an idea on how to recognizer if I have solid or hydraulic lifters in my P90A please share. The picture isn't the best unfortunately. -Any idea how to pull the water temperature sensor. I already destroyed mine after it was stuck in the thermostat housing. The little nut came out but the sensor didn't... Hopefully this thread will become popular once I start doing things. Anyone can tear apart a motor so its not that interesting... My goal to finish everything is June 30th. I go to summer camp that day and its about an hours drive so that will be my break in time. Quote Link to comment Share on other sites More sharing options...
pete280z Posted April 27, 2008 Share Posted April 27, 2008 Hey Josh - I don't have a lot to add but it's cool watching you dig in and make progress. Can't wait to see that stroker on the road. Quote Link to comment Share on other sites More sharing options...
wherezmytofu Posted April 27, 2008 Share Posted April 27, 2008 ah, you are doing the whole "no rear bumper" thing. can u post a bunch of pictures from different angles of how your rear end looks thx Quote Link to comment Share on other sites More sharing options...
josh817 Posted April 27, 2008 Author Share Posted April 27, 2008 I do need a bumper. My friend ran into the back of me at 5mph and the only thing that stopped him was the exhaust pipe. >_< Atleast he offered to pay for it but I can just bang it out I think. I would like to buy one but don't have the money. I will probably just make a metal bar and attach it to the bumper mounts. It won't withstand a 30mph hit but if I was stupid and backed into a light pole my tail lights would be safe. Help any? Quote Link to comment Share on other sites More sharing options...
wherezmytofu Posted April 27, 2008 Share Posted April 27, 2008 cool thanx Quote Link to comment Share on other sites More sharing options...
calpoly-z Posted April 28, 2008 Share Posted April 28, 2008 Well P90A means it left the factory with hydraulic lifters. Plus I don't see any nuts or threads in that crappy pic you posted of the valve train so I would say you have hydraulic lifters. If there are studs and two nuts to lock the rockers down then it is solid lifters. If not, then they are hydraulic. By the way, you'll be hard pressed to get the power you could have gotten for $700 through megasquirt and a turbo than with a N/A stroker, but I feel you on the need to be different. Good luck from a fellow young texan. I've been there and you're lucky your dad knows cars. My buddy and I learned the hard way... through lots of failure. Quote Link to comment Share on other sites More sharing options...
Daeron Posted April 28, 2008 Share Posted April 28, 2008 you won't get ALL the way up in your power goals, but a good running set of SU's will let you break in your engine and give it enough fuel to give you some NA fun by all means.... Just a thought, I don't know if you have any SU hardware around or not but if you DO, they WILL work on the stroker. They might want to be re jetted (I am not really a carb person, I am just regurgitating what I have picked up elsewhere) but I know people have run 3.1L with them in the past. You may also be going too aggressive with the camshaft selection.. High lift, high duration camshafts do not just make for more power, they move power up in the band (obviously you already know this) and ALSO DESTROY power lower in RPMs (ie, takeoffs are NOT quick; rolling starts are.) A big, lopey camshaft like that will also kill your fuel mileage, and at $4/gallon the difference between 15MPG and 22 is the difference between paying 270 in gas every 1,000 miles, and 180 in gas every 1,000 miles. (UTTERLY CRAZY when you think about it that way, but I checked my math three times.) I can't tell you those are precise estimates of what MPG you might achieve, but there will be a difference. To REALLY squeeze that power, AND that life expectancy, out of a stroker engine, REALLY requires a top-notch cylinder head, built by the best. Or a reasonable facsimile thereof. Just keep that in mind and read EVERYTHING you can about cylinder heads, and look at lots of pretty pictures of combustion chambers, and unshrouded valves. Building a powerful, naturally aspirated, carbureted engine is a true art form; don't get discouraged if you wind up coming to the conclusion that you have to settle for less than you want right now. This is the reason so many people opt for the turbocharger... With boost comes instant gratification! (well, once the boost kicks in anyhow ) Some of us do still believe in the delayed gratification available in having your throttle instantly available. Quite the dichotomy, eh? Turbo lag comes hand in hand with instant gratification, and discipline, dedication, and perseverance result in instant throttle-up! Quote Link to comment Share on other sites More sharing options...
josh817 Posted April 28, 2008 Author Share Posted April 28, 2008 Actually I figured with some set backs, my RPM range should get back to usual. 3" exhaust doesn't just increase flow but it also pushes the RPM down by a little. That cam should be could up to 7000RPM so thats good too. Not looking for a drag car, more like a track car. I want the Z to be as trackable as a street car can legal be. This way when I get out of college and I lose the BMW, because I KNOW Dad won't want to give it up, all I will have to do is rebuild my spare L24 block and take out some things from the car and I'll be ready. I will also compensate for a slightly dead 0-60 take off by putting in a 4.11 diff. its all good. ! I have the Weber DGV's and Dad says they're good carbs easy maintenance but he is speaking for Triumphs and not Datsun. Most people I hear say they suck and rather go to SU's, as for me, I'll stick with triple 40mm. Gas mileage? Don't care. The turbo motor didn't do any better than 20mpg on VERY nice driving. OK I COULD spend the money on college books but I will work extra hard to get that money. Besides, UT you ride a bike not a car. I understand its not going to be easy to do this project and its not easy to make a high powered NA carb'd motor, especially an old one with non crossflow blah blah blah. But thats what I like. My last post I purposely kept out the sentence "its easy to make power from a V8 or a turbo motor" because I didn't want any arguments but it comes off that way to me. I won't question how easy or how hard it is though. If it was easy to make power with a turbo then I would be keeping it now wouldn't I. I think if time becomes a REAL problem with the BMW (we have been working on it for a year now and the next racing license is this Setember), then I will just have Dad put in a fuel cell and an ok roll cage into the Z and use it as a track car for that weekend. Doesn't tickle my fancy putting it up to those sort of stresses but if we need to it will be done... There are only 2 classes a year so you know... Quote Link to comment Share on other sites More sharing options...
josh817 Posted April 28, 2008 Author Share Posted April 28, 2008 Well P90A means it left the factory with hydraulic lifters. Plus I don't see any nuts or threads in that crappy pic you posted of the valve train so I would say you have hydraulic lifters. If there are studs and two nuts to lock the rockers down then it is solid lifters. If not, then they are hydraulic. By the way, you'll be hard pressed to get the power you could have gotten for $700 through megasquirt and a turbo than with a N/A stroker, but I feel you on the need to be different. Good luck from a fellow young texan. I've been there and you're lucky your dad knows cars. My buddy and I learned the hard way... through lots of failure. Well.. 400hp isn't in my grasp any day. BUT I will be satisfied with 200+ I think. Even with 1psi of boost (tried to keep the turbo all nice so I could sell it) it still felt nice and that CAN'T be a good amount of power... Only reason why I asked about the head is that I was hoping I would get lucky and have an early P90A head which had solids. Otherwise I'm left with trading/buying a P90 or doing the hydraulic to solid conversion that Big-Phil made a video about on Youtube. If I can find the correct hardware then I'll do that. ALSO, if you remember me saying Dad knows a lot of quarky trick **** to do to motors. I saw I have a cylinder head temp sensor on this motor, towards the rear of the head. I also read the cylinder 5 has some cooling issues. Our plan is to have the water temp. and that sensor going into a switch, and then 1 wire from the switch to the water temp gauge. This way I can switch between the 2. Now, I don't know normal head temp. or if it will max out the water temp. gauge but hey, its cool. Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted April 29, 2008 Share Posted April 29, 2008 Lets see, hp goals of 200-250, 3.1L, agressive cam....You SHOULD be able to do it if you assemble everything right and polish up the heads/intake system well. I'm making inside that range at the wheels on my 3.0, but I'm running ~9.8CR and 34-36* of advance, so YMMV. I'm interested to see the results of this though Quote Link to comment Share on other sites More sharing options...
josh817 Posted April 29, 2008 Author Share Posted April 29, 2008 Yah thats another issue, timing. I need to read up on how much advance to run... seems like its been debated so I can't make a clear confident choice. Same goes for degreeing a cam. The sticky'd thread says you should be within 1-2 degrees, but I saw a guy posting his dyno results showing a 2 degree change made like 15+HP. I guess it will take expensive dyno time. I'll just have to wait until the club has another group dyno, or maybe the Z club around here but the latest one was the one with Big Phil's dyno run so there probably won't be another too soon. Quote Link to comment Share on other sites More sharing options...
josh817 Posted May 5, 2008 Author Share Posted May 5, 2008 Alright guys I had to make 2 trips over to the shop this weekend so thats slightly annoying. 30 minutes to and from with idiotic traffic. The block is ready to go to the machine shop! Spent some time tearing it down and this time I used power tools rather than wrenches. On the L24 block I had used wrenches and it took forever to get everything apart. Air rachets and impact driver is the quick way to a tear down. Except... when it came to the main bearings, well that took forever because they're wedged in, especially the rear main seal. I really would like to meet the machine shop man, Rick. Dad's been doing business with him for 20 years so I trust his work, maybe even get a deal or something but I don't expect one. Its his business, and business is business no matter who usually. The crank, pistons, l24 pistons w/ rods, block, and box of stuff to vat are all going this round. The head is later on, he just needs to take it apart and vat it. We will do the porting and polishing and then send it back to be cleaned up and put together. The rods are a similar deal. He will press them out, vat, we will lighten/polish/debur them, send them back to be pressed onto new pistons. This is where I get cheap though and I don't know if its much of a big deal or not... Dad says he'll have the rods shot peened. Well thats cool but I'm on a budget and I feel that Nissan rods were pretty beefy anyways. It can't be too much though and I will probably do it anyways since we are lightening them so that beefy sensation has disappeared. The same goes for balancing. I am only doing rods and pistons rather than the full rotating mass. I feel bad about it but thats a MAJOR expense which is probably worth it but we must remember that this isn't a track car. I heard people say 30-50% of power can be lost from that sort of thing but we'll see. If this motor is a mess up then the next won't be. Live and learn. Hate it. I'm seeing what people mean by aim high for price estimates. I have one price here but after Dad said shot peen, and ceramic coat, well what else... I know I'll have enough money but I split the funds up, body work and motor. Now I'm digging into body work which basically means paint isn't coming anytime soon... Speaking of money... The machine work should take 2 weeks, he's a week behind in work right now. This is good and bad. Good because the guy who bought my turbo setup is out taking care of a stolen car of his. He must not have access to a computer because every time he sends me a message, I reply, by then he's gone and I have to wait another 3 days. Essentially, I don't have funds to cover machine work but I told the guy that I need the money in 2 weeks. I know he will send it but I don't know how long he is going to take. My concerns are having a bill I can't pay not only making me look like a dead beat but my dad's integrity also drops slightly since my work goes through him. We'll see. My other concern is that I won't make my dead line. Not because I can't work that quickly but because of shipping. I do hope MSA ships well because I plan on grabbing one of their cams. I would say order now but... money again... I'm in this pickle because I purchased 40mm carbs with a pump, reg, filter, manual, assorted jets, and How to Rebuild a Datsun Motor for $805. Score baby. During this down time I must build a project for physics. An electric trolley car sort of thing which has to travel 10 meters, then travel back the 10 meters in 30 seconds. The power comes in through 2 cables which are connected from 1 wall to the other, and the car sits or hangs from it. The trick is having it go one direction and then come back and you can't touch any of it. Dad suggested a timer set for 15 seconds, when its up have it reverse the polarity and go the other way. The teacher said about the same thing but instead of a timer just have a switch so when it reaches the end, something will bump into the wall and flip the switch. We'll see. Pictures: NOTES: -Kitty litter works wonders for spills. I used a lot... -If anyone knows the magic number for lightened rod mass that would be great. Unless you just lighten them as much as you can. -Are pulleys interchangeable? I want the L24 pulley on this motor because I'm not running A/C but I don't know if that is going to send balancing out the window by a bunch. Use a Maxima pulley to match the crank? -Donations to the paypal account "gracefullearner04@yahoo.com" would be great Kidding, send your money to Hybridz. Quote Link to comment Share on other sites More sharing options...
josh817 Posted May 24, 2008 Author Share Posted May 24, 2008 Well finally another post. Things have been dead lately due to weekend activities. Here's where I'm at now. Rod preparation. I didn't aim for lightening the rods but I did want to remove any flack or cast marks on them. The concept is a tricky one for me because I would think that removing metal makes them weaker but apparently any sharp edges or corners are stress spots. Cracks and breaks will occur in those areas first so what you do is round them off and grind away the seams. I'm still now done with the rods yet as they need polishing to be perfect but they're good to go for the most part. Balanced them within +-1 gram but that was on Dad's triple beam balance. I'm trying to snag my friends digital postal scale for better results. I received my carbs today and I was very impressed. With the carbs came that "Datsun OHC" book, flipped through it and saw some important things about rods. Mainly, replace the 9mm bolts for 3/8" small block Chevy rod bolts. I don't know if its a little bit of over kill but I'm keeping my eyes peeled for some anyways. More good news on the home front, I found another head with all the works on it for very very cheap. This time I won't let it by me. If I get it, I'll save about $600-$800 depending on how I want the head to be. This money is going to go back to MSD (was going to leave it out until I made more money), tires for the new wheels, refurbish the radiator and get electric fans, and a Supertrapp muffler (if you're in Texas and know if its legal or not please tell me, I think its fine though). Oh and last weekend I went to do some flag work at our club races, took some video although its not the best. The sounds are lovely though, if you have ear plugs, otherwise it just kind of sucked until the end of the day when you didn't care anymore. http://tinypic.com/player.php?v=w5mo0&s=3 Group 4 I think, its either 4 or 7. Porsche's, Z's, BMW's, etc. http://tinypic.com/player.php?v=hs1iz8&s=3 Group 1 Big bore cars. The dude in the front we suspected wasn't following the rules because he had the fastest lap for the weekend, beating the Formula Atlantic cars by 2 seconds. The difference between him and legitiment 2nd place was half a lap after 10 minutes. The funny thing is that he was so quick for all the races except for on Sunday when the points race came up he blew his motor. NOTES: Nothing this time. Quote Link to comment Share on other sites More sharing options...
woldson Posted May 24, 2008 Share Posted May 24, 2008 WOWZERS that's alot of metal. I know what you are saying about edges and points I kinda like to see some of the machineist weigh in on this. I personally considered doing this my self as well, buuutttt. Quote Link to comment Share on other sites More sharing options...
josh817 Posted May 24, 2008 Author Share Posted May 24, 2008 Yah I know. I'm hoping it wasn't a mistake but I trust what Dad says. Just recently he built a hot race motor for a guy and it blew up a piston, literally, the first day he went out and ran it. This wasn't Dad's problem because the guy told him to use stock pistons on 12:1 comp Triumph motor, bad idea. My point is that when we looked at it, the piston was in the oil pan and the pin was still in the rod, which was perfectly fine and Dad did the same thing to the rod. Anyways we'll see I guess right? I don't know how much I took off because our triple beam balance only went up to 570grams or something and it maxed out. We had to take out some washers from under the plate to get it to work. At that point I set them all to 574g but like I said, this 574g isn't REALLY 574 since we had to take 3 of the washers out. This is ok because when balancing mass is only relative from rod to rod. Get your lightest rod and then match all the other to it. I guess to get the real mass of the rod I would weigh the 3 washers and add that number to 574g. Or just use my friends digital scale... Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted May 25, 2008 Share Posted May 25, 2008 In my opinion you need to look for some new rods. Those may work just fine but they may also make thier way through the side of your block. My concern is that you removed material in a very random fashion from what I could see in the pics you posted, by doing it the way you did I feel you probably introduced several new stress points as well as moving the balance points of your rods all over the place. I have done to my rods what you are attempting to do to yours and there is a correct way to do it, but it is also time consuming and difficult. The first thing is to use a fine stone on a bench grinder to remove the casting seams on the sides of the beams VERY IMPORTANT when doing this only work from end to end NOT from side to side, any marks in the beam from the grinder should run up and down the beam only. At the big and small ends of the rods where the grinder wheel can not reach use a 2" or smaller wheel on your grinder to do that part. Across the top and bottom of the rods you have "balance pads" you need to leave enough material on them to balance the rods after you are done with everything else. Now that you have all your rods ground down evenly with your large and small diameter wheels it is time to remove all the grind marks from the rods, the tool for the job is a Cratex rubber grinding wheel like this: Cratex Straight Wheels - Large SizeCratex Large Wheels have found wide application for removing rust, heat marks, tarnish, excess solder, scratches, corrosion...blending in and polishing welded seams after rough grinding...polishing bearing surfaces and raceways...removing burrs and breaking edges...smoothing and polishing castings and punched or sheared pieces...wet sanding of gem castings...wet sanding of gem stones...trimming plastic articles...smoothing glass edges...cleaning before welding or soldering...and for countless other deburring, smoothing, and polishing operations. Hole sizes shown are the minimum diameter recommended for the various wheel sizes listed and wheels will be supplied this way unless larger holes are specified on your order. Wheels with larger holes can be ordered at the same price, providing hole diameter is a multiple of 1/8" and does not exceed 1-1/4". For other hole sizes, request pricing. Maximum Safe Speeds in Revolutions Per Minute: 1-1/2" dia. - 15,000; 2" - 10,500; 2-1/2" - 8,300; 3" - 7,000; 4" - 5,250; 5" - 4,200; 6" - 3,600; 7" - 3,000; 8: - 2,600; 10" - 2,100. These speeds are based on 5,500 Surface Feet Per Minute. Best results are usually obtained at 30% to 80% of Maximum Safe Speed. Use light work pressure. Cratex Wheel Mandrel - Part No. CRA.1342 Cratex Wheel Mandrel No. 1342 has a 1/4" shank and is designed for 1/4" center hole wheels up to 3" diameter by 1/3" thick or less. The maximum safe speeds listed above are for 1/2" overhang or less (exposed mandrel length). For each additional 1/4" of overhang the maximum safe speed is decreased by at least 20%. Cratex Dressing Block - Part No. CRA.6404-2148 The Cratex Dressing Block is ideally suited for truing, dressing, and shaping all Cratex Rubberized Abrasive Wheels. The shape is easy to handle, and the combination of fast cutting abrasive with a hardened bond provides an easy to use, efficient, and long lasting dresser that will enable you to achieve optimum performance from all your Cratex Rubberized Abrasive Wheels. Size: 6" x 1/2" x 1/2" The quote above comes from this website: http://www.newmantools.com/cratex/index.html As you can see you can get these in different sizes, you can also get them with different grits, use the same diameter Cratex wheels as you did grinding wheels and work the beams on the rods with them untill you can no longer see any scratch marks from the grinding wheels. Once you have reached this point balance the rods, if you or your father are not able to do that yourselves pay the two or three dollars each to have them done. On a different note the 40mm carbs may be a little small for the cam you are planning on running. I am running a smaller cam than you in a 3.0 liter stroker with 40mm Mikuni's and I had Dave Robello custom machine some 38mm venturis for them which added about 30 rwhp but a set of 44mm carbs would have been better. Dragonfly Quote Link to comment Share on other sites More sharing options...
josh817 Posted May 25, 2008 Author Share Posted May 25, 2008 Thats what I did. Used a bench grinder with a fine wheel and ground the seems out and rounded the points around cap area. As I said in the post, I'm still not done. The final step is to get the air grinder (whatever you want to call it) with a very fine sanding wheel on it, and get rid of all the scratches and such. All the spots where you see the light reflecting in a different way will be polished out completely. Afterwards check the mass again and you're on your way. I trust my dad and how he does his work on the race motors. Even though he doesn't know the L engine, he knows how to do certain things correctly. The rods of the L series aren't special in any way so I treat them the same as all the other race rods we do... other than lightening that is. The only thing I didn't pay attention to was the direction of grinding BUT hopefully the polishing will take care of that. I was afraid of that with the carbs... I can't find 44's or 45's for a decent price though... My 40's came in just yesterday along with a fuel pump, regulator, some big chrome filter, manual, Datsun OHC book, spare jets, and a water temp sensor that I needed. I guess I'll just deal with it until I get the money to go up a notch... 45's are so expensive though, if I did it I may just go over to ITB's or Mikuni motorcycle carbs. That would be damn sexy. How much were the custom venturis from him? My only doubt is that I won't have a head that flows nearly as well as a Rebello or Sun-whatever (brain fart) head since I'm doing it myself too. I guess while I'm at it, are there any water jackets I have to worry about hitting when I port this thing out? Thanks for the help Dragon Fly. If you have any other good advice please share so I don't hurt myself when its all up and running. XD In my opinion you need to look for some new rods. Those may work just fine but they may also make thier way through the side of your block. My concern is that you removed material in a very random fashion from what I could see in the pics you posted, by doing it the way you did I feel you probably introduced several new stress points as well as moving the balance points of your rods all over the place. I have done to my rods what you are attempting to do to yours and there is a correct way to do it, but it is also time consuming and difficult. The first thing is to use a fine stone on a bench grinder to remove the casting seams on the sides of the beams VERY IMPORTANT when doing this only work from end to end NOT from side to side, any marks in the beam from the grinder should run up and down the beam only. At the big and small ends of the rods where the grinder wheel can not reach use a 2" or smaller wheel on your grinder to do that part. Across the top and bottom of the rods you have "balance pads" you need to leave enough material on them to balance the rods after you are done with everything else. Now that you have all your rods ground down evenly with your large and small diameter wheels it is time to remove all the grind marks from the rods, the tool for the job is a Cratex rubber grinding wheel like this: The quote above comes from this website: http://www.newmantools.com/cratex/index.html As you can see you can get these in different sizes, you can also get them with different grits, use the same diameter Cratex wheels as you did grinding wheels and work the beams on the rods with them untill you can no longer see any scratch marks from the grinding wheels. Once you have reached this point balance the rods, if you or your father are not able to do that yourselves pay the two or three dollars each to have them done. On a different note the 40mm carbs may be a little small for the cam you are planning on running. I am running a smaller cam than you in a 3.0 liter stroker with 40mm Mikuni's and I had Dave Robello custom machine some 38mm venturis for them which added about 30 rwhp but a set of 44mm carbs would have been better. Dragonfly Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted May 25, 2008 Share Posted May 25, 2008 Keep the pics coming... I would like to see the pics of the rods after you are done with them. The cost of having Robello doing the venturi's in the carbs was not that bad, the bad part was how long it took to get them done and back. Here are a few pictures of the venturi's. stock venturi and modified. stock venturi and modified. installed in one of the carbs. Here is the link to Dave Robello's website if you decide to go that route. http://www.rebelloracing.com/ Dragonfly Quote Link to comment Share on other sites More sharing options...
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