flexplate differences between oem turbo motors and non-turbo motors.
- Thread starter towcat
- Start date
compensating for something....larger wrist pins perhaps?
Interesting information. I just looked at the picture of one of my flexplates. I assumed it was from a factory n/a motor. According to your pictures, it is with one difference. Mine only had 2 balance holes drilled in it. Now I want to get home and look at my other one that was in my truck when I got it. Thanks!
The question now is, why the difference? They are all internally balanced engines right?
The question now is, why the difference? They are all internally balanced engines right?
icanfixall
Official GMM hand model
When I built my turbo engine I don't recall any of those holes nor the balance weights on the flexplate I got from BTS. Not saying they were not there. Just don't recall seeing them. I recall the guy doing my balancing mentioned the weight he had to add to one end and the mid plain to balance the complete rotating element including the flexplate.. And the only differance was the new pistons. This was after the engine melted down too. I had the first rotating elements balanced. I can't see the reasons for adding so much weight only because of a differant set of pistonns. After the first shops work nothing was really out of the question for the work I got. Thinking back I really got screwed on what I got.. No reach around or even a kiss... Just screwed... Nice pics too...
bingo.
since there isn't any difference in the cranks, there has to be compensation somewhere else in the rotating mass.
only reason why I posted the pics was there was a question at one time about the differences between the two. I just happened to have both handy for the pic opportunity.
idiabuse
Full Access Member
balancers are different too for Turbo and N/A I am searching now for the pic I took.
Javier
Javier
good to know.
i have a two oem turbo motors here that is going to find a new home shortly. one motor is sickly and the other one in good shape, neither will find a home in any of my trucks.
icanfixall
Official GMM hand model
I recall way back in the last century somewhere around the late 97 or 98 years someone posted about turbos on the small wrist pin na engines. The posting claimed the turbo would add so much pressure on the pistons that it would stick the piston to the pin thus ruin the engine. I actually never read anty post where that happened. I ran my na engine with a Banks turbo boosting to 12 lbs for many hundred thousand miles. Not one wrist pin was damaged. Now I have a na engine that I built up with the same turbo and this engine has the large wrist pins in it. I did balance everything that rotates down to 1/4 to 1/3 gram differance in weight on each piston. The flexplate and the dampner was part of the balance calcuations too. The only part that was not measured was the main bearings because they do not rotate.. I do read where many large wrist pin engines are grenading too but really don't know why thats happeneing. Everyone knows I wont red line my engine. I understand these engines have a design built into them to run on the rev limiter all day long and as long as they have oil, fuel and coolant they will take that and continue fine. So whats wrong with the "turbo" engines throwing rods. Or are we looking closely at this and running with it. Compared to the number of na engines to "factory turbo engines any blown turbo engines will be a larger % than a blown na engine. So we can't use those numbers. I'm not worried about my na engine thats running the large turbo wrist pin rods either.. Just wondering what the deal is with the engines. There even is some printed information from Franklin that the turbo block main webs are 110 thousands wider than the non turbo blocks... Well I have not seen that yet and they both use the same width bearings. So where is this increased web width.. I really don't think it igsists myself... Also Franklin said not to run a turbo on the na blocks.. It wont work very well or for very long... Well thats right up off the stable floor. None of the big three turbo makers could be so sucessful selling the turbo kits for the simple na engines without lots of law suites... We really need to talk with an engineer that was in on the design of these engines both na and turbo..
HiHorse
Full Access Member
Thanks for the info. I have been looking for used parts but have not located one for the 94 turbo engine yet. I really want to be working on this crew cab, however, I will have to replace the engine in my payloader first! Bad timing too, started knocking and lost all power right before we got 22" of wet, heavy snow!!
pics are worth a 1000 words. besides, I'm too lazy to type.
1) the non-turbo motors have balance holes drilled into the flexplate.
2) the oem turbo motor has additional balance weights added to the motor side of the flexplate.
Gary,
My?about turbo engines throwing rods would be WHERE, main end or wrist pin end? Are the larger rods just machined out MORE for larger wrist pins thus making thinner heads or are the heads where wrist pins fit larger too?
My?about turbo engines throwing rods would be WHERE, main end or wrist pin end? Are the larger rods just machined out MORE for larger wrist pins thus making thinner heads or are the heads where wrist pins fit larger too?
icanfixall
Official GMM hand model
Well Al I have laid the turbo rods and non turbo rods side by side. They are not simpley drilled out with less meat around the pin location.. Same with the pistons. So from what I'm seeing is the rods and pistons are designed to handle the size and weight. Its just in valuable information coming to this forum thru trusted members with plenty of hands on experiance that causes me to ask questions. I respect the findings of both of these long time members but want to know more about why the turbo engines throw rods. The reasons have so far escaped me. Adding meat to handle the added weight of a larger wrist pin mechanically tells me then added weight is not a facter for throwing rods. The actuall engine I'm running turbo rods in now had thrown number 5 rod. It broke just above the rod bearing but never left the crank so the oil pressure didn't drop. I have no idea how long the guy ran that engine before shutting it down.. He didn't seem like he knew what the hell he was doing.. But he sure knew how to cover the 1/2 cut in the oil pan with mud and dirt so nobody could see the hole. That was a simple tig weld repair too. I saw the engine was sitting outside in the desert back yard where I got it from so I knew full well the cylinders were going to be wet.. They sure wqere but I had no idea it thru a rod till I had cranked it and found out it would not go 360 degrees. Then I saw number 5 piston had not moved.. Thats when I got pissed off. But I had a 120 mile road trip and the cost of the engine was only $87.50 off ebay so I made out ok. Just don't like being lied too.
racer30
Full Access Member
Hey old bull, That is the first gen psd rod, It says DIT Not IDIT. I just checked my Turbo rods and NA rods They are the same 1.1 inch wide with .880 wide bearings.
trust me on this. they are physically different. if you need proof by video teardown, just say the word.
i can supply photos, video will take a little longer.
does that mean I need to make a road trip? to bring the sick one to the northern hospital
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