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Engine Specific Info and Questions => IDI Engine => Topic started by: subsonic on March 07, 2008, 12:02:11 pm
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After hearing about Daves suspected bent stock connecting rod, I decided it would be wise to look at upgrades.
I can have a reputable speed shop near my house polish all 4 connecting rods and then shot peen them for about $120.00. From what I have been reading, this in itself will not strengthen the rods, but make them more reliable. What it will do is remove any area's for potential micro cracks and stress relieve the newly polished rods. All good things.
A new set of H-Beam connecting rods would come polished, stress relieved and balanced. They would also offer additional strength, something that polished stock connecting rods would not.
The choice would seem obvious. The problem is that in the real world, the best choice is not always available. The only 4340 H-Beam connecting rods I have seen are Pauter and go for about $700 bucks. Way out of my price range with everything else I am spending money on.
When I have asked around about the high price I am told it is because the 1.6TD rods are not that common, thus the higher price.
Are there other H-Beam connecting rods out there that are used for more common applications ( cheaper) that could be made to work in the 1.6TD with modification that will not compromise the strength?
I mean I see SBC H-Beam 4340 connecting rods for sale starting down at $350 for 8 of them! Why the hell do I see conecting rods listed as VW / SBC ???? Do small blocks and VW's share a common dimension?
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Probably the SBC/VW H-beam rods you are seeing are for Aircooled engines. It's a pretty popular upgrade when building a drag-prepped Aircooled VW to have a modified crank and pistons that will accept SBC rods. (in stock form the dimensions are pretty close)
Depends on what you are building I guess. Unless you are putting maximum stress on the engine, I'd go with the polish/peen job, as the 1.6 rods are pretty stout. (from what I've heard, better than the 1.9 rods)
Good luck!
Brendan
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That would explain all the SBC references. Anyone else have any info?
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Hellooooo....... (echo.........echo.........) :wink:
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Wouldn't it be a better idea to get/make a Passenger Performance style intake. I believe the reason behind the bent rod was that #2 and 3 cylinders recieve the majority of the air, blah blah, resulting in the rod failure. The redesigned intake would solve the problem at the source making the altered rods unnecessary. Hopefully someone with more experience could chime in. :roll:
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From Passenger Performances post on the Franken:
I had a chance to ride in it, last weekend. It is a MONSTER, we hit 200km/h+ no problem and was still pulling hard when Dave let out, this was only 22psi, as he was having some other boost issues at the normal 28psi that is usually run. It drives around off boost about as quick as a stock TD with boost. Perfectly comfortable for daily driving. I'm sure once Dave gets all moved in and caught up with his orders he will make a video. There are still a few more tweeks that need to be done. Cam, exhaust mani, and probably a different turbo as this one surges bad past 28psi. Dave and I both suspect at least one bent rod as well. This would hold true for approx hp with Andy2's findings when he bent his rods as well.
That was with the high speed intake manifold. I will have one as well.
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I believe heat treating the rods helps with strength. All the hi-po stock Chevy rods were heat treated and polished.
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I know heat treating will impart a harder surface on the metal. Shot peening is supossed to stress relieve the part.
I found this really neat article and movie about a new process called laser peening. They claim it offers 4 times the benefit of standard shot peening.
The first link has a movie explaining standard shoot peening.
http://www.metalimprovement.com/shot_peening.php
This second link is for the laser peening.
http://www.metalimprovement.com/laserpeening.php
http://
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maybe Eagle rods would made you cheaper rod if you send them dimensions?
http://www.eaglerod.com/
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What needs to be done to the connecting rods prior to having them polished and shot peened?
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Not a whole lot of info out there I guess.
I dropped my connecting rods off this morning. They will be magnafluxed, polished and then shot peened. The shop may hold off on the shot peening until the balance job is done. If they have to remove any material, it would wreck the shot peening in that area.
I will be having the rotating assembly balanced at this shop as well. Crank, pistons, pins, rings, rods, rod bearings, flywheel and bolts etc.
It is going to run me about 220.00. The guys at the shop were cool with me coming in and shooting video of the balancing. Some time in the next few weeks. Will post pictures of the polished rods before the get shot peened.
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very cool
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$220 for the whole treatment to all 4 rods? Not a bad deal if you ask me.
Would love to see pics of the process.
Brendan
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Slight change in plans with the connecting rods. They are going to be polished and then shot peened. I am then going to bring them back to my bud at the machine shop. I will have the new ARP bolts put in, and then have the big end resized. I will also have the new bushings pressed in on the small end. (anyone recommend one brand over the other?)
After this is done it will be back to the speed shop for balancing. The guys there said that they could take material off the connecting rods for balance purposes in areas that will not effect the shot peening.
Just dropped off the crank. All nice and clean, had the journals polished, still came out standard, nice. Pistons, pins rings and clips are there as well. Need to sort out what I am going to do for the flywheel, and than get the appropriate preasure plate, bolts etc. Have to go through my box of new parts and find the bearings for the rods. Moving forward.
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$220 for the whole treatment to all 4 rods? Not a bad deal if you ask me.
Would love to see pics of the process.
Brendan
It's 220.00ish for the balance on the rotating assembly.
Getting the work done on the rods:
22.00 each for polishing.
9.50 each for shot peening.
6.50 each to magnaflux.
90.00 for new ARP con-rod bolts.
20.00 for new con-rod bearings.
10.00 for new wrist pin bushings.
So now I'm up to 272.00
Resizing the big end would be about 16.00 each. I get the good buddy discount so I don't need to cover that, but if I did, I would be up to
356.00
Thats half way to a set of Puater H-Beam Rods.
Jeez, this adds up quick!
272.00 to do the rods.
260.00 for pistons
150.00 for ceramic coating the pistons.
$682.00 just into the connecting rods and pistons!
:shock: :shock: :shock:
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Well, I spoke with Dave this morning, and he had pulled the head after the alternator bracket broke and knocked out the water pump, the motor got kinda hot, so he pulled the head just to be safe.
The head was flat, and all rods and pistons were in good shape, and there were NO BENT RODS!! It looks like one of the valves has made contact with the piston, it was checked over was straight no damage to the piston or the valve, so it was put back in and the valve spring was checked over. Now if you have been following the franken motor thread you will know that the big limiting factor to this point was that the turbo was surging above 26psi so Dave custom machined an anti-surge compressor housing for it and now can run 35psi, however above 32psi it just flutters now as the external gate spring is to soft, so Dave is going to get a harder spring, and attempt to re-dyno it this weekend. Both with the stock injector's and then with some 1.9 dual springs with some merc nozzles. It still needs an equal length exhaust manifold, and a cam, but it is getting there. :wink:
Subsonic I am looking forward to the results of your build.
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Oh... The point of my last post...
I think that stock rods appear to still be holding just fine. :wink:
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That is just fricking music to my ears Brett! I was really worried about the rods, thought about it all the damn time!
"I'll never be able to run full boost!" :cry:
I am glad to know I will have a little buffer with the polish and peen and balance.
How the hell did valve contact happen? Think it happened at max rpm? Float?
I wonder if that piston is a hair above the other ones on piston projection?
I sent those injectors to Dave! Those are the one I will be using in my build. I don't need them yet so run em hard :twisted: I will be interested in seeing if the Merc nozzle route was worth it. I hope they can put enough extra fuel out to get past his 200hp goal.
What's this here new fangled anti-surge compressor look like?
I don't think I am going to be able to put up numbers like Dave with my turbo selection. I think it will spool faster, but I will get spanked in the top end.
.48 A/R Turbine
.42 A/R Compressor
45 Trim
Here is the turbo map for it.
(http://www.not2fast.com/turbo/maps/t3-45.gif)
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I'm not sure what the compressor cover looks like, as I just spoke with him on the phone about it. I would "assume" that it is a gun drilled style, vs slots, as it is a lot easier to machine, but then again Dave isn't known for taking the easy way.
That turbo is about 5/8 the size of what Dave is running.
As far as the valves, I really don't know we talked about it a bit, but didn't come up with anything concrete. It has HD valve springs, and only one hit, and not hard enough to bend the valve... So???
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I went and picked up my connecting rods this morning. They certainly look different. I will get some pictures up later today. After the polish, each rod came out 1 ounce lighter. Still need to swap out the old bolts for the ARP's and have the big ends resized. That should happen in the next week or so.
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What do you think? I thought that the sides would have been done as well, but the guy at the shop said that would take a lot more time and the real benefit is on the sides. I still think the look pretty cool :twisted:
(http://i239.photobucket.com/albums/ff120/subsonic44/DSCN0361.jpg)
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Those do look cool. How much (if any) was removed from the end cap? Do you know the total weight of each rod after the work?
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I do not have the starting weight. I was told the they are all approx. 1 ounce lighter than in stock form. If I go digging in the attic and set up my reloading scale, I could get a current weight. The weight will change though when the stock bolts are replaced with the ARP bolts, the big end is resized, and the pin bushings replaced. There was no material removed from the big end that I can see. To me, it looks like if you spent some time on them, you could clean up the sides and the top to achieve a much smoother overall product, might lighten them up around another 1/4 ounce or so. On the small end, the 3 clamping surfaces have been removed. That is where the majority of the weight came off I believe. If anyone has a picture of a stock 1.6TD rod, I will post it next to one of these for comparison.
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Just dropped off the rods, new ARP con-rod bolts, and bearings to my friends shop. Old bolts are coming out, new ARP's are going in, and the big end is going to be resized if neccesary. New pin bushings should be delivered in a week or so and then they will be installed.
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New ARP rod bolts are in! Rod was .0001 out after installation. Resized it to perfection 8)
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Wrist pin bushings are in. The wrong ones were sent the first time. Brand new Mahle one will be going in the next day or so.