TurboRaider@work

For a 2†diameter valve this is how I would figure the area: 3.14 times the radius squared. 1 x 1 X 3.14 = 3.14 sq inches. Also be the time the intake is closing you are getting a pressure buildup in the cylinder since it has been filing and the piston is now coming up. Not saying boost is not a factor, but I am saying it’s a bit less than you think.

No, didn't see a need to. Saw no need to. I believe the journals are where it counts, and they are still stock spec. FYI- There is a SQ out there making very high numbers that has a knife-edged crank. That is 88whiteStarion's 456hp car. Good to hear that others have had sucess with the weight reduction. Since the stock turbo crank was salt bath nitrided from the factory your right, no need to do it. I used a caravan crank because I was having a hard time finding a good used Starion crank. The down side is the caravan crank is not hardened. I chose ion nitriding because it less likly to distort the part, I only have one crank to heat treat and if it comes out wrong I'm SOL. The surface came out super hard, I am very pleased with the results. Kevin

I got the crank nitrided at Accurate ion http://accurateiontechnologies.com/default.asp There are crank shops near the nitrider that can grind, nitride and polish your crank. The total cost of having them do the work is usually less than dealing directly with the nitrider. Try Velesco crankshafts. I think I posted info on them before. Kevin

The balance will still be ok ( or close to it ) because the counter weights are opposed to each other by 180º. What was removed off of one side of the crank was removed off the other. 4 Cyl cranks are not balanced using any bob weights, they just spin the crank, it will look fine on the balancer. However the counter weight at each rod journal does isolate forces locally, It’s there to counteract the weight of the rod / piston assembly. Since a good part of that is now gone more of the force to balance out the mass of one piston going down will be another piston going up. There is no reason this can’t work, but the mains bearings will be taking more of a load, as will the crank itself. A way to get some balance back is to drill out the id of the rod journals. If you look at some race cranks you can see how much they hollow out that area. Some counter weight removal is good esp with the lighter forged pistons. Kevin C

That I can help you on... I have shims to adjust the preload. Just drop the unit off and and its a 30 min fix. The 4X4 units I am building eliminate most of the the preloald so they have better manners on the road in snow and ice. The idea is that with less preload and more plates the unit will act as an LSD once pre-loaded against the brakes. This is a common trick with LSD units when off road to get extra traction. The reason I want less prelaod is that this will be going into the front diff. So far its just an experiment. I will post results when I get the unit together. For the back, you want the preload. Also too much LSD additive makes the unit feel loose. Try buying Redline without the additive and add it seperatly. Add just enough to get rid of any chatter. BTW the axle spline are differant from 87 vs - 88-89. Kevin

I am building an LSD unit for the front of my TurboRaider and need a doner unit for extra clutch plates. A complete LSD or just some clutch plates would be great! Thanks, Kevin

1/2 qt in the filter, 1/2 in the oil cooler (hard to change that 1/2 qt) and four quarts in the pan. The pan spacer puts 1 exta qt where it really counts, in the pan. Kevin

Dad, Can you let me know the pin height and dish volume? Thanks, Kevin

The nice thing about ion nitriding is the growth is about .0002 after trating and is only needs a polishing before being used. http://accurateiontechnologies.com/default.asp These are the guys I used, I can look up what I hardened my crank to when I get home. Kevin

Yes, A decent overheat will / can anneal your heat-treating. If the journal got blue it is suspect and should be hardness checked. That was why I was looking for a undamaged crank, but most used ones I looked at have gotten hot from a failed rod bearing. Kevin

The test the nitriders need is the alloy content of the metal so they know how long process the part and at what power level. To get that you need to send them a metal sample to be put in a mass spectrometer or something along that line. The guys at advanced ion just stuck mine in and let it run. Some alloys are designed to allow deeper and faster hardening when nitrided so you don’t need to run them as long or you get better results. Kevin

Velesco in cali will harden and polish a caraven crank for about $150. Kevin

My experience was that the passenger car crank / non turbo, (as your testing shows) is not hardened. I was able to find a used passenger car crank that had never had a spun bearing a lot easier than a decent turbo crank core. The only issue was getting it hardened. I sent mine out to accurate ion nitriding and I am very happy with the results. Shops can get a decent price on repeat orders. There are some shops that are close to the nitrider that will grind, polish, nitride and final polish for about $150 per crank. It’s tough to find a nitrider willing to do small orders and or they want a lab test of the metal before they run your part. Accurate was decent to deal with and gave me a generic setting to specify with my order that worked very well. They are the shop that hardens a lot of the custom billet cranks from grinders in California (my crank got run with a batch of SCAT cranks) . Ion does not tend to warp the crank like a salt bath process. I can mike the crank and not worry about leaving a mark on it. The new motor gets test fired this weekend. BTW, unless the rods I got used were not starion rods they are not nitrided. Kevin C

Eric is great to work with. After getting parts from others (esp on E bay) that were poorly packed, the wrong part, took weeks to ship and or had inflated shipping charges its great to deal with someone who properly packs parts and ships quickly. Excellent to do business with, Thanks, Kevin

Don’t want to get into a bolt war…. But I do want present what I have learned about fasteners and materials in general. Under normal conditions the head bolts wont permanently deform. If they are over tightened that might, or if the head gets really hot on an over tightened fastener they can deform… Most times the head gasket crushes. Torque to yield fasteners cant be reused because they yield point keeps getting higher and there is no easy way to know when they are properly tightened once they have been used. If you could directly measure their clamping force they would be fine to use again. Also your standard 2.6 bolts won’t lose strength from being used. If they are over stresses and permanently deform, even if necked down the yield strength will actually increase up until the neck down is very noticeable. This is because the bolts are work hardening and the strength is actually increasing. I know this may not seem believable that even as the fastener necks down it gets stronger but its true. If you want to learn more get a materials science book and look at the tensile testing section for steel. What can happen to fasteners is the thread friction increases with usage. This can and will reduce the clamping force. This is why its so important to make cure the threads are clean and well oiled (washers too). This is where new can be better … If the friction is less. A side note note…. Your head gasket will hold its best on a warmed up motor. Since the head expands more than the bolts as the engine gets warm the clamping force goes up. So save your 25 psi boost for when the motor is completely warmed up. Kevin C