Author Topic: 1.6td connecting rods, polish and peen or h-beam? Pictures! (Read 11182 times)

subsonic · « **on:** March 07, 2008, 12:02:11 pm »

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?

lord_verminaard · « **Reply #1 on:** March 07, 2008, 12:30:31 pm »

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

subsonic · « **Reply #2 on:** March 08, 2008, 06:52:03 am »

That would explain all the SBC references. Anyone else have any info?

subsonic · « **Reply #3 on:** March 08, 2008, 11:00:30 am »

Hellooooo....... (echo.........echo.........) :wink:

rallydiesel · « **Reply #4 on:** March 08, 2008, 11:24:56 am »

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:

subsonic · « **Reply #5 on:** March 08, 2008, 11:54:38 am »

From Passenger Performances post on the Franken:

Quote from: "DVST8R"

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.

jimfoo · « **Reply #6 on:** March 08, 2008, 01:29:17 pm »

I believe heat treating the rods helps with strength. All the hi-po stock Chevy rods were heat treated and polished.

subsonic · « **Reply #7 on:** March 08, 2008, 02:29:07 pm »

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://

zaprzal · « **Reply #8 on:** March 09, 2008, 12:55:03 am »

maybe Eagle rods would made you cheaper rod if you send them dimensions?
http://www.eaglerod.com/

subsonic · « **Reply #9 on:** March 09, 2008, 08:27:27 pm »

What needs to be done to the connecting rods prior to having them polished and shot peened?

subsonic · « **Reply #10 on:** March 10, 2008, 07:39:31 am »

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.

burn_your_money · « **Reply #11 on:** March 10, 2008, 07:41:08 am »

very cool

lord_verminaard · « **Reply #12 on:** March 11, 2008, 01:39:21 pm »

$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

subsonic · « **Reply #13 on:** March 12, 2008, 11:46:36 am »

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.

subsonic · « **Reply #14 on:** March 12, 2008, 12:35:18 pm »

Quote from: "lord_verminaard"

$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: