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Paging John V or Thomas F

swedefiend

swedefiend

...
Joined
Jul 30, 2004
I could rant for a minute, but I think I'm too tired for that...

I'll just stick to the task at hand.

I'm putting together a 91 b230 with mostly stock parts.

Everything was going good until I went to put the pistons on the rods.

I cannot get the clips from Venolia to seat with the pin installed. It looks like I need to take .001-.003" off of the length of the factory pin to get them seated.

I know the factory pin is tapered and that it would be important to keep them that way. Will it be okay to just lightly work each end with a flat file? Like slowly and carefully work each end just enough (trying ever so earnestly to keep the file perpendicular to the end of the pin) to get the length just right for the clips to seat?

Also, when fitting the pistons to the rods - do the arrows face forward on the factory pistons? I'm pretty sure they do but the Bentley just says to make sure the "notch" on the piston crown is aligned with the identification # stamped on the rod. I'm guessing that the notch must be on the earlier engines, because I've not seen one yet (and all of the engines I have scattered were 87+).

Anyway, the pin bosses are offset and I believe they need the fat side of the piston to face the starter side of the engine. I just want to make sure I get this right.

---

The rant would have to do with paying a machine shop to check things like this to make sure I don't discover them at midnight on Saturday night. Then me being naive enough to think that they would have checked the end clearances on the wrist pins.

Now I have a tweaked circlip and will have to work this out on my own after I order a few extra clips from Venolia on Monday. :roll:

The good news is that all of the ring gap clearances and rod/ crank clearances are exactly down the middle :-D

I have been plastigauging my heart out because I am a little nervous now after all of the incidents with my "alternate" machine shop (read - not $90/ hr labor rate) although it appears it may have been wiser to shell out that dough.

Anyway, thanks in advance.
 
Some of what you describe is not clear.

The factory [mahle] pistons are either notched or stamped with an arrow indicating "to the front" of the block positioning. And that is because the wristpins are offset to the thrust side...the right side of the block...AKA the oil filter side of the block. Installing the pistons with the notch [or arrow] towards the front of the block thusly locates the pistons correctly: the wristpins will be offset towards the oil filter side.

The con rods...the factory rods...also have a 'direction of position': the stamped numbers indicating which cylinder [stamped on the rod and on the cap] are all supposed to be towards one side of the block as well: the oil filter side of the block.

What is not clear:
...you are using factory wristpins? replacement pins that duplicate factory pins?
...you are using factory type wristpin circlips? round wire types
...or circlips supplied by Venolia? probably flat wire types; probably tapered/beveled on one side....meaning that you can install them backwards; with disastrous consequences.

You do not file wristpins. You do not file on wristpins.

What is the axial clearance for the wristpins to the circlips on the pistons supposed to be? zero? or a couple of thou? or less than zero? I can't see how it could be less than zero; or zero: that would prevent the pin from being able to rotate.

The volvo wristpins are full floaters: they rotate in the piston and in the rod bushing. They are beveled on the ends: to assist in keeping the round wire circlips in the grooves.

You need to discuss this with Venolia. They should know, and be able to tell you what the axial clearance should be on those pins...in their pistons. And how the circlips are to be installed.

HTH

Thomas Fritz
...the stealth FTi
 
stealthfti said:
Some of what you describe is not clear.

The factory [mahle] pistons are either notched or stamped with an arrow indicating "to the front" of the block positioning. And that is because the wristpins are offset to the thrust side...the right side of the block...AKA the oil filter side of the block. Installing the pistons with the notch [or arrow] towards the front of the block thusly locates the pistons correctly: the wristpins will be offset towards the oil filter side.

The con rods...the factory rods...also have a 'direction of position': the stamped numbers indicating which cylinder [stamped on the rod and on the cap] are all supposed to be towards one side of the block as well: the oil filter side of the block.
Click to expand...

This is inline with what I noticed. The "fat side of the piston" being oriented towards the starter side indeed indicates the offset being oriented towards the oil filter.

stealthfti said:
What is not clear:
...you are using factory wristpins? replacement pins that duplicate factory pins?
...you are using factory type wristpin circlips? round wire types
...or circlips supplied by Venolia? probably flat wire types; probably tapered/beveled on one side....meaning that you can install them backwards; with disastrous consequences.
Click to expand...

The circlips are provided by Venolia. They may be tapered. This could be the reason I am having a problem. I did not notice them being tapered, but I will definitely take a second look (unfortunately, I have little else to do but sit and look at it at the moment)

stealthfti said:
You do not file wristpins. You do not file on wristpins.
Click to expand...

I didn't think it would be okay. They seem to be of similar construction to the cam lobe surface. I believe they have been carburized or treated in some other similar fashion. It was a silly question posed from sheer desperation.

stealthfti said:
What is the axial clearance for the wristpins to the circlips on the pistons supposed to be? zero? or a couple of thou? or less than zero? I can't see how it could be less than zero; or zero: that would prevent the pin from being able to rotate.

The volvo wristpins are full floaters: they rotate in the piston and in the rod bushing. They are beveled on the ends: to assist in keeping the round wire circlips in the grooves.
Click to expand...

Should be a couple of thousands, but I couldn't swear to that. I am sure it shouldn't be zero, but unfortunately the clearance is less than zero. Tis more than frustrating. I really need to get this thing running ASAP.

stealthfti said:
You need to discuss this with Venolia. They should know, and be able to tell you what the axial clearance should be on those pins...in their pistons. And how the circlips are to be installed.

HTH

Thomas Fritz
...the stealth FTi
Click to expand...

Yeah, it seems at this point that I should just pack it all up and ship it off to Venolia and have them do this part for me. I didn't think that I would have this much trouble since the Venolia slugs I ordered were pretty much just copies of the OEM piston. Even though spending more money on this engine at this point makes me cringe, I think the difficulty that I am facing right now indicates that someone with more experience should take the lead for a second.

As usual Thomas, thanks for the reply.
 
You're welcome.

And I understand the frustration. I did not think that you were really serious about taking a file to the wristpins; but their not fitting in there and letting the circlips seat would be irritating as hell.

Just what it is that is not right is still not quite clear.

As I can visualize it, a couple of possibilities come to mind:
...the circlips, if they are of a flattened wire look, should have a bevelled edge, or be convex [or concave] on one side. This is to help 'push' them into their grooves when the pin slides over and touches the circlip. I realize that I may not be describing that well or accurately; but the point being that the circlips likely have a front and back that are different, so as to allow for a little added seating pressure.
...it might be possible that the grooves cut for the circlips are off size; i.e., not quite far enough apart.
...it may be that the wristpins themselves were not faced on the ends correctly, either to the final length dimension spec'd, or that the correct shape of bevel was not machined onto the ends of the wristpins to match the circlips supplied to you.

Was there a dimension and specs sheet supplied with the piston set? And did/does it have the wristpin dimensions and circlips specifications listed?

Comparing the writpins and the circlips to the spec sheet might help identify the culprit.

It is possible that you have not done something correctly. And it is possible that Venolia did not do something correctly.

If you can eliminate the error-on-your-part possibility, then that leaves Venolia holding the bag.

Small comfort, for sure. But at least you would know where the problem is.

And if the error is theirs, then the cost of correction should also be theirs.

TF
 
Gone... Back to Cali.

Next day there, next day back.

Dale says he's gonna "fix me up". Hope they're back here before the weekend :x:
 
Well I'm a bit confused where you say "factory" wristpins.

-----> Are you meaning OEM Mahle 24mm pins???

They're chambfered on their ends so any tendancy to escape will have their leading edge below the circlip and the taper will push the clip into the groove.

If you mean the Venolia pins??

What sort of locks?
Round wire locks? What diameter?
"True Arc" circlips??
"Spiro-Locs"

True -Arcs have a slightly rounded side and a straight side as a result of the stamping process, the straight side MUST go outwards.
Spiro-Locs are interchangeable with True-arcs and can go either way.
But since you didn't swear worse than me or mention lots of BLOOD,
I'll guess you didn't choose Spirol-locs.

So even tho you sent the things back, others may be or someday be in so telll us what you HAD.
 
Yeah, factory pins.

Flat wire clips.

There was quite a bit of swearing getting the buggers in the hole.

Then I found out that the other side was impossible to seat. If Ben hadn't been there calling me a p*ssy for being so lit up, then there probably would have been blood. Or tears...

But, I can only hope for the best when they return.
 
swedefiend said:
Yeah, factory pins.

Flat wire clips.

There was quite a bit of swearing getting the buggers in the hole.

Then I found out that the other side was impossible to seat. If Ben hadn't been there calling me a p*ssy for being so lit up, then there probably would have been blood. Or tears...

But, I can only hope for the best when they return.
Click to expand...

OK you better call the MFG and tell them the pin you're using came in a piston with ROUND WIRE LOCKS.

You probably should send in a sample of the pin so they could measure it accurately.

4 pins, with flat ground ends in fawkin 24mm should cost about 24~~~ ea and that may be the smartest solution, and maybe a set of "Tru-Arcs" which have ears with holes like a common internal snapring. $2 each and 5 seconds a clip.

To the rest of you and especially all you guys lining up in your dozens for the 6.3 rods:

Whatever else you do make sure you specify "Round Wire locks", and also now you see why I choose a common off the shhelf pin diameter and length.

Lots of luck Svenskarnasfiende
 
Now, things are clearer.

When you sent in a sample piston, did you include a wristpin and the round wire retainers?

And when you say stock, referring to a 91 B230, then that should mean stock 152mm C-to-C rods, with wristpins that are 23mm x 65mm. The B21/23s used wristpins that are 24mm x 72mm. And both the B21/23s and the B230s use round wire retainer clips. Which also means that the wristpins are chamfered on the ends so that the wristpin can actually extend a bit over the circlip, not just up against it.

If you did not include sample wristpin and circlips with the sample piston, then that could explain the problem. Just going by the dimensions of a sample piston, and cutting the retainer clip grooves the same distance apart in the pin bores, and then ASSuming that the wristpins are flat on the ends...for flattened wire retainers...would explain why you could not seat the retainers on one side. The grooves inside the pin bosses are less than 65mm apart, because the wristpins are chamfered on the ends.

If you did include pins and circlips, then Venolia messed up a bit: they did not doublecheck what you sent them and "see" the chamferred pin ends, and then redistance the retainer clip grooves so that the flattened wire clips would fit in there with that 65mm long wristpin.

From what you have described as the problem, the above scenario appears likely. When you get the pistons back, let us know what was done to correct the clearance problem.

TF
 
stealthfti said:
From what you have described as the problem, the above scenario appears likely.
Click to expand...

100%

50/50 on the fault though :)

Thanks for the replys!
 
Last edited:
Picture_008b.jpg


This brings me much pleasure :-D
 
stealthfti said:
When you get the pistons back, let us know what was done to correct the clearance problem.

TF
Click to expand...

They machined the ends of the pins. I wouldn't think it would be an ideal situation, but they were very smooth when I got them in my hands. I turned them over and over hoping not to find any ridges or burrs. You do this hoping not to find a splinter or cut ;-)

Anyway, they were as smooth as a baby's rear and I learned a trick for putting in the circlips. (John, maybe they are "Tru-arcs" - I keep forgetting to ask.) Using a snap ring plier only to set the clip in the hole and then using a "pocket stick" shaped like a C to ease the tension while I used my thumbnail to push the clip into its seat.

Anyway, they're in there now and I gotta wait to get the rest done. I have to strip parts from my other engine and I need a few more parts from the junkyard. Hopefully by Tuesday next week, this thing will be in the car.
 
I'm glad it worked out. And it should be perfectly fine. Cool.

Good luck with the rest of the build.

TF
 
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