@1magnit every Aftermarket rod, steel or Aluminum I've balanced cranks with were withing 2grams, if you think 2 grams makes a difference the how do you compensate for oil under the piston on the up stroke, verses oil under the piston on the down stroke, there are simply to many variables to try for perfection, cause it can never be obtained, I've run a Stewart Warner model 2000 engine balancer since the mid 70s, and had customer's from Oklahoma, Kansas, Arkansas, Louisiana, Texas and New Mexico, I was running 3% over balance long before most even knew what it did, don't over think the balancing, if it's jumping up and down on the machine, you aren't done yet, but spinning one 6000rpm isn't going to give good results, that's why S&W uses around 440rpm, when you spin it faster it will smooth out, but slow it will hop all over the place...
@@ChiefCabioch We're talking about dynamic balance, it's a 60 degree V6. There's about a 100g difference in weight between a stock rod and a cheap china rod.
@1magnit new rods lighter? Or heavier?. If heavier your going to be putting in some heavy metal plugs, but I'm talking about the machine he's using, I don't see that machine is accurate and you have 2 planes of balance, static and dynamic and you need to lock one side while floating the other, I've been balancing engines for 50 years, not much you are going to discuss I haven't dealt with,
Hey man, I appreciate your documentation of the 6G7X family. I'm a enthusiast myself and own a NL Pajero thats being DOHC swapped and a 2nd gen 3000GT VR4. Can you get me your email, whatsapp or any platform we could discuss. TIA
It's not really legal to drive on the road, I'm spending time building bigger engines for backup. A 6G72 with 74 crank and mivec at 3.35 litres, a 6G74, a stroked 6G74 at 3.9 and a 6G75 at 4.4, ish with DOHC mivec . This engine from 2012. I'll max it out on a dyno one day when I'm ready.
I stopped in order to rework the water injection to make it a parallel to the fuel injection. 6 extra injectors for port injection. Work still in progress. As of right now the crank balancing is no 1.
@@1magnit How do you get 4.4 liters with 6G75? Do you have a non-standard crankshaft? Tell us how the supercharged mivec system behaves. I have an engine in a similar configuration in construction, but I do not yet know how it will behave on the road.
There's plenty of good descriptions on youtube, the best one is probably from Steve Morris Engines. He only does V8s and the balance factor isn't the same, he DOES mention though that the bobweights should be concentric but doesn't know why.ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-hjmijDXVNUU.html
Once the factory balance factor has been determined then the next step is to move to another crank that's been both stroked and had the counterweights cut down slightly, check it for balance using the same balance factor of rotating weight and a % of reciprocating weight, then make adjustments to it so it balances correctly. The most important aspect is that it's NOT a V8 crank, it's NOT a 90 degree bank angle and it's NOT a 50% balance factor. If you just put one of these cranks into a shop for rebalancing they'll do it with a 50% balance factor which is wrong, it'll fail prematurely, the first sign being excessive vibration and the 2nd sign, excessive wear on the middle main bearings.
To follow on from this, the bobweights need to be concentric, as in all of the mass distributed evenly around the journal, otherwise the numbers come out all wrong.
I've had a bit of a holdup on the balancing machine. When you mess around with the balance (bob) weights with different geometry, it balances with a different total weight.20g strips of plate don't add up the same as a stack of washers. The crank will balance dynamically at a different total weight. These weights are vectors and need to be added together as vectors and not using addition. The answer is to make new bobweights which are concentric as far as weight distribution goes. I'm using the same big end caps for centres but I've got some used wheel weights which are lead, I've melted them into rods, got some aluminium pipe cut for a mold. I need 2 sets, for 6G72 size and for 6G74 / 75 size. What???? So you think you can just drop off your crank at the local machine shop and they balance it for you by clicking their fingers together. They know what they're doing? It's always done wrong. It's not even close to being a 50% balance factor as used by 90 degree V8s, it's completely wrong. The vid on balancing from Steve Morris is worth watching, he even says the bobweights need to be concentric but doesn't know why. Because weight X plus weight X at 90 deg to each other add up to a lot less than weight 2X, If you're not quite sure what I'm doing here I've got a pretty much virgin 6G72 crank, I've made bobweights to simulate real pistons and conrods and I've got it spinning at about 1200b RPM without jumping around .If you pay to get the job done it'll be done not only wrongly but at maybe 500 RPM. 830g is pretty close but I'm getting closer. What balance factor is that?
The answer to the question is because the mass isn't distributed concentrically and so when you add the extra weights hanging off the ends you've got to add them as vectors.
Hello. I am a Japanese 22 years old. I have a GTO SR and I am thinking of porting a diamante 30m mivec. I am going to ask a GTO custom store to do it instead of doing it personally, but that custom store has never done that porting before and said it looks difficult, so I would like to know (1) how to do it, (2) parts needed, and (3) points to tweak for the store, please. Please reply if you feel up to it. Best regards!
There's a few FB groups associated with porting. Best to join one of those and ask there. If you don't know what you're doing , best to leave it alone. Most of the gains are always at the seat and if you don't have the right tools, you can't do it.
I ran across your channel because I was curious to see if you can dual overhead cam a 6g75. I also see that you possibly work at a machine shop I watch this other channel called I do cars he just tears apart engine cores and throws crankshafts and camshafts and stuff like that in the scrap pile because he does not feel comfortable telling it however I believe you guys both could get something out of this if he sends you free crankshafts and you point him in the directions for engines and stuff like that it would be mutually beneficial for both of you plus your channel could grow
I'm building all sorts of things but this is a machine for dynamically balancing crankshafts. I can recondition crankshafts with the grinding machine and also do offset strokers so this is the next step You can contact me through FB on the GTOperformance site and send a msg. I'm in Wainuiomata.
@@1magnit yeah thats definitely the dayco one it has my allen key in it instead of the grenade pin haha. That belt and water pump I sent should also be dayco ones
What sort of mileage would you expect before you'd need to replace the seal? I only replaced mine because i had to change out the pump due to my own fault. Otherwise the other one was fine on over 370,000 ks.
I only replaced mine when it started leaking, it was quite loose, it had just been pressed in rather than glued with RTV. I use RTV on everything, all gaskets, all seals. No leaks. In fact the one that leaked would have been the original one from 1991
Cold oil is a bit thick for these sorts of tests. Diesel would be better for showing up any defects. I can do a freeflow test and measure the volume flow rate. Can do a zero flow test and measure the pressure set by the relief valve. I can do both tests with oil, then repeat both tests with diesel. I've got 4 pumps on hand right now. One measures like brand new it's done less than 5000Ks. Others have done more but actual is unknown. There's 3 specs to measure. The outside gear to the case. The gears to the cover plate. The tip clearance. Combining all 3 specs then flow ad pressure tests will determine how good any used pump actually is. No guesswork..
@@1magnit I always wondered if the over pressure springs actually work and if people test them. Ive got a 6g72 dohc mivec on the stand, disassembling it lately. No car to put it in yet actually.
@@Michael-lg4wz The non crossover blocks use an 11mm wide gear and the GTOs / Pajeros use a 12mm gear. That's one reason for measuring the flow. One of many reasons. The relief valve , it's supposed to open at about 80 PSI, testing might confirm. The spring for the relief valve, the manual says it's 43.X mm long but mine is 45 mm.
Hey, awesome stuff, really following your content recently. I'm also balancing my engine, but my approach is to write a programme to calculate the balance factor. Lets see how close we get to eachother!
I'm not actually trying to balance it just now, just trying to work out what balance factor was used in the factory. The balance factor isn't ever exact anyway. If you think about it as an x axis balance and a Y axis balance with a single cylinder then what's required with weight is different for each axis. Anywhere in the middle will work. If you get it perfect for the X axis, then it will be a long way out in the Y axis and vice versa. I've now got a display on the scope from sensors but need more work with more and different sensors.
As an example, if you weigh all the required internal parts from various 6G74s, the SOHCs use much lighter pistons than the DOHC pajeros, they're lower CR. The cranks are all the same. The rods are all the same. I'm under the impression that aftermarket dynamic balance is a total waste of time and money if all you're doing is changing pistons and rods.
@@1magnit Hey dude, my programme was being an idiot as it had several bugs. Finally ironed them all out and checked with a crossplane V8. I got an optimum balance factor of 51% for a V8 (this balance factor changes with geometry). It all lines up nicely with reality. Inserting the geometry of our engine (subject to changes/errors as the numbers I got are from the internet) our engine needs a balance factor of 52.5%. I assume a rod length of 141.1mm end to end, 76mm stroke, negligible pin offset.
@@pereduranofcourse How does your programme work for the distribution of the weight? In a V8 you want it all in the ends In a 60 deg V6 you want 1/3 of it in each section.
I had it a bit faster before this vid. It started jumping around quite a lot. It still needs maybe an extra 5g on each bobweight, Maybe more but it's quite close. I've got 3 options here. Make my own crank balancer. Take my cranks to Brian and get him to do it for me. Then no 3. Do both. That's best. He told me a few years ago that 60 deg V6s don't balance like 90 deg V8s. I've got 3 frankenstein cranks, all different to balance plus a stockish one. That's a free add for Brian Howat engineering. The usual formula for balancing a V8 crank is 50% of the reciprocating weight and all of the rotating weight for each of the bobweights which replace the piston and conrod for balancing. Google will usually tell you that for a 60 deg V6 the formula is 30% or even less. It seems to be closer to zero, As in all of the rotating weight and zero of the reciprocating weight. The exact figure, I'll close in on it gradually through lots more testing.
That one might be a bit hard to understand. Going back to basics, if you've got an engine block with all the main bearings in it, You drop the crank into place. With lube on all the bearings, no caps fitted, the crank should turn freely. When they're bent , they have a tight spot every 180 degrees when you turn it. Same thing here except the centre main bearings are not fitted but 2 dial gauges instead on the journals indicating the runout.
What's the easiest way to add up to 3.2 g on these bobweights? Welding wire. I've cut off the right length, wrapped around the bolt between the nuts. They're now all 516g +/- 0.5 g. They're all still just a bit light. but it's time to upgrade the test gear to make a proper DIY balance machine.
The new drill, it's 900W and supposed to be about 800 rpm at no load, So when it's flat out, should be about idle speed .I removed the main bearings no 2 and 3. They're old ones in there, I used the ones most worn to make as loose as pos. Lubed with assembly lube so NO, the crank won't get damaged. I've got to mod the bobweights to make them adjustable.
That's why you don't throw away old parts. I've now used up 2 whole sets of factory rods to make bobweights for all 6 journals .Plus the bearings of course. Otherwise they'll flop around too much.
What tooling did you use ? I have a van Norman bar and was thinking of the same concept. I was going to weld a carbide in a 90° position to the end of the normal carbide holder. What did you end up with ?
Watch the dial gauge really carefully. It was meant to be zeroed but it's sitting 0.02 mm below to start with. After opening and closing the valve the base circle drops to below the starting point.
From the figures, there's one and only one way to set up cams and that's using peak lift. If you try to get the opening and closing points the same, the peak lift will be different and wrong. That's with stock cams, If you're playing with aftermarket cams, there's a very good chance they were made all wrong so it's so much worse.
I can't quite remember the specs on the cams, it's buried somewhere . Normally you'll have 18 to 20 inches vac at 750 ish rpm hot idle. Now I've got about 10 inches vac at over 1000 rpm. I can't slow down the idle speed any more and there doesn't seem to be any leaks Maybe it's the cams? They're extra long duration, close to 300 deg but lowish lift. I only did that to see if it would idle with an AFM because many aftermarket cam suppliers say it won't work even at 280 deg.
@@All_handson_deck Sounds are deceiving. It doesn't drive well at all at 1000 rpm and 30 mph in 5th. Got to cruise in 4th. It's lost a lot of low down torque but revs out really well. The boost used to be 12 PSI but now it's 5 PSI so there's a few things to check up on and diagnose, But for 5 PSI it pulls well . I've got another set of cams to swap in but want to get more data on these ones first. The next ones are a bit shorter duration and more lift. Plus it's winter here and I'll leave big jobs for warmer weather.
If you want to re torque the head, ????? One bolt at a time. Clean the head of it. Use white paint, mark the front of it. Back it off. If it's still tight , take it out and lube it. Put it back in. Use a beam type torque wrench to torque back to original position and mark the number. Then retorque to spec and note the difference., Both the difference in torque as well as the difference in position. Then you're nearly a pro.
The cooling system always has lots of pressure in it once hot. I stripped the inside of one of the head bolts many years ago. Can't retorque that one nor get it out. I've tried a few things but don't want to over heat any of the valve springs It'll do until I get a new engine together for it. It's just a stock 91 TT with cast iron crank. Going back over 3 years I cooked it quite bad on the hill. I retorqued both heads, they all took an extra 90 deg, all except the stripped one. It hasn't overheated since but neither has it used a lot of fuel. It'll get to the beach and back without losing any coolant.
And 13Gs, increased wg preload runs a safe 12 pounds on 95 RON. There's a second set of injectors installed but no fuel lines yet. The wiring is there for them as well as wiring for 3 more coils.
