std rods:shotpeening and ARP bolt question

[Jobi Joba]

STOOOOOOOOOOOOOP.

Firts,read my posts:I said,it SEEMS that the noise I heard was due to the side clearance of the rods...Here is why I say that:
- no bend valve (double checked)
- rocker arm clearance ok (reshimed to the best spec)
- piston pin play ok,no excessive at all
- cylinders rebored
- brand new pistons
- brand new camshafts
- oil pressure really good and no play on the crank

So,IMHO,it can only be due to the side play of the rod,OR to the radial clearance between rod and crankshaft, i.e. the big end diameter of PAR rods is 51.025 (bigger than std Nissan spec) which makes me choose the grade 2 for the rod bearings.But even with this spec,the radial clearance is 0.062mm (std is 0.030 to 0.055mm and limit is 0.09mm).The only way to match the std spec is to grind the crankshaft...

Now,here is a lil' report of all the problems I had with PAR rods
- piston pin bushing inner diameter:too small...had to rebore it of about 0.05mm
- thickness of the small end of the rod:too wide for the piston gap.Had to machine the sides of the small end of 0.8mm or something on each side
- PAR connecting rod big end inner diameter:51.025mm.Std spec is 51.000mm to 51.013mm...(really dunno why...)
- thickness of the big end:thinner than std rods...side clearance is out of limit (std is 0.2 to 0.35mm,limit is 0.5mm,clearance with PAR rods is 0.55mm)
- weight difference of 4g between lighter and heavier rod (but I do consider this is not really important as I managed to match everything when fitting heaviest rods with lightest piston and removing the extra weight from the heaviest rod/piston couple)

Who has built your engine?? Did you put it together or did a 'professional' engine builder? Whoever did put the engine together did not do their job properly and you deserved anything that could go wrong to the engine to go wrong. But please don't put blame on anyone else. It might sound harsh but is true.

I built my engine...cause I don't trust anyone else.I want more from myself than from anyone else.

It doesn't matter who built and put the engine together, the fact of the matter is that the engine was NOT blueprinted during the assembly stage. Yes, blueprinting does take more time but it will find any small defects early on which could then be addressed.

If my engine is not blueprinted,then no one is... :roll:

It doesn't matter that items are made for a specific engine you still need to blueprint and double check the items that are going together.

Everything is even triple checked,trust me...I knew I was out of spec for the side play of the rods...but I asked several guys developping engines all day long and they told me it SHOULD be ok...and now it SEEMS it was not.

I don't know what work you do but sandpapering the piston pin (gudgeon pin) bush in the small end of the conrod is a vary bad idea and not professional at all. I'm sure you have heard of honing the cylinder walls, this is the same method that should be used to hone and remove a smidgen of material from the piston pin bush.

Ok,ok...now I know what honing means (I didn't know before,had to search...),I can tell you that I used this technic to rebore my piston pin...I used the word sandpapering cause I thought it was the best word to describe the operation...In France,the translation of honing would be something like "stoning" (from "stone")...and I thought this was not the proper word,so I used the one I thought was clear enough to make everyone understand.

I personally don't use the PAR rods in my engine as they weren't avaialable when i needed forged conrods, i went with ARGO connrods. These too don't have the oil hole from the big end, you will find that most forged conrods won't have them either.

So what?Never said that it was a problem...I was surprised PAR rods don't have this lubricating hole,but it seems that it's a common fact and that it doesn't change anything for the reliability of the engine...So no problem for me...

Oh and did you expect that all conrods are made the same? Did you ask for the weights of the rods before purchasing them? You mentioned they were heavy in your post. My ARGO rods are 120grams lighter than the stock rods for comparison.

Lucky boy!!PAR are only about 15g lighter than std rods if I remember well...But I didn't bought them to have lightweight rods but to have stronger rods...so I was not really upset about their weight.

The piston pin bush is deliberately made slightly smaller so that the engine builder can hone the bush to the exact specs to fit the piston pin being used.

Ok,so Nissan says the std bush is: 22.000 to 22.012mm (when installed in rods).
That's why piston manufacturers produce piston pins which give a clearance of 0.005 to 0.017mm...because they just want their piston pin to fit the std rods...
So tell me how people who buy PAR rods should have strange piston pins?
Catch my drift?
Ok,blueprinting...but I hope all engine builders can use 3 dimension measurement machine (as I did) to check all the specs with an accuracy of 0.001mm...but I doubt it.



BTW,as someone asked:
- PAR rods are not all the same width...I saw a difference of 0.09mm between the thinnest rod and the widest rod of my set...
- PAR rods are thinner than std rods...from 0.005mm to 0.015mm I'd like to know why...and it's possible to blueprint a part if you have to remove metal from the part...not if you have to add some.

But I will only blame PAR if I don't hear the noise I heard before when I start the engine again with std rods which is not sure.

Just one thing to conclude:a forged part should NEVER be machined as it will break the metal fiber.And forged parts are so strong because the fiber of the metal is not broken,as it is on machined parts...
It was just to add an important point of view about state of the art engineering (we're talking about that,aren't we?) and how hard blueprinting is with forged parts... :roll:

 

[campbellju]

:lol: :lol: :lol: :lol: :lol: :lol:

That was an e-mail and a half Jobi.

"sandpapering" :shock: ....not surprised as my French only goes as far as buying a beer, not talking about machining engine components. :lol:

Again.. I appreciate the efforts you have gone too and the detail you have put into your post to help other members. My engine is still at the machine shop so I am still none the wiser but will confirm any findings I have when I have them.

Jim.

 

[campbellju]

This is now getting silly :evil: :evil:

A part from one of the rods being thinner, the internal diameters of one of the big end is also too small and will need to be machined. Specification is 51.000 - 51.013, actual is 50.846.

It gets worse, but the details are sketchy at the mo. My engine builder reckons the "slots for the shell bearings are in the wrong place" so we'll need to machine new grooves for them to fit in.

He mentioned there was a lip or something on one of the rods and the shell bearings protruded from the rod as well but he started rambling at this point so I said I'd go and see him.

He's going back to the machine shop again soon to get a quote for getting this lot fixed. His estimate was around £200!!!!!!!! This is why he called me to see if PAR could help out or something else about rods, shoving and a**es This will take the total maching bill to nearly £300 :x

Blue printing is one thing, DIY after market parts is another.

I believe from other peoples experience around the forum that PAR service is not great. I've not checked yet but I wouldn't expect much. I can understand why in some ways as if I were PAR, I would want to see the part before I made any comment as to whether it was their mistake or not. This would probably mean me posting the rods back at my expense and waiting more months to get the engine back together.

In reality I have little choice as I've already sold my old rods and to buy some from another manufacturer would take weeks and cost too much now.

Ivan, I don't know if you're reading this but I would appreciate any advice as like Jobi before me I am finding it difficult to remain objective and I want to know if anyone has fitted these rods successfully before I continue to spend (waste) more money.


Jim

 

[zia]

jim if your machiner is in doubt about these rod then the best bet would be get another standard set!!, if any thing save your self future hassle if the rods end up being the weal link in the engine :?


zia

 

[Edd]

i can get you a set of std rods if you need them as my mate has set spare, pm me if you want, sorry to hear of your problems :evil:

 

[R-Type]

In the August 2004 edition of Jap Performance mag there is a 400 bhp impreza P1 which is using a Par box. If you read the article you will find the owner had a few 'issues' with the fitment of the gearset & resorted to sending it back to Par for 'sorting out'.
It SEEMS Pulsars are not the only cars afflicted with quality issues from PAR.

 

[campbellju]

Thanks for the support gents. I feel better after my rant.

 

[Websnowbo]

If the grooves for the shells are in the wrong place then i find it hard to believe they are even the correct rods!

A the end of the day, why would PAR manufacture a rod that was different to standard (Apart from material).

 

[Odin]

A the end of the day, why would PAR manufacture a rod that was different to standard (Apart from material).

That's a question we would all like the answer to mate :? :roll: .

There's to many people haveing to many problem's for them all to be wrong, And what do we get from Par silence :evil: .


rob

 

[campbellju]

Got this off the PAR website about their con rods :lol: :

Strict attention is paid to detail and finish. Set weights matched to ± 1.5 grams. Big and small ends finished to ± .001mm of bottom sizes, which allows the professional engine builder to set the right clearances for the intended use of the engine.

:lol: :lol: :lol: :lol:

I also picked up they only give a 6 month warranty from purchase so I doubt they will be very helpful. I'll try though to give them the benefit of the doubt once I've got all my info together.

Anyone dealt with these guys :

www.lateralperformance.co.uk
166, Merryhill Road.
Bushey, Herts.
WD23 1DG

Apparently they are the UK distributor for PAR.

 

[Odin]

just got this from Par.




Hi Robert, Greetings.

In regards to weight, all our rods are matched in relation to weight. What
needs to be understood is that the rods cannot just be weighed statically on
a set of scales since they are dynamic within a working engine. In an engine
the rods rotate as well as reciprocate, and in turn the rods need to be
balanced in this way also. The neck or beam of the rod is in reciprocation
in an engine and the big end is in rotation, therefore the rod needs to be
balanced in 2 sections, 1. the beam and 2. the big end. This is what we do,
we match all the rods to within 2.5 grams on the big ends which is what is
most critical in engine balancing and within 4.5 grams on the beam of the
rod. These are all tested and proven tolerances. If the rods needed
balancing we would list this in our instructions.
What is listed in our instructions and what is most critical by far in a
performance engine is clearances. Par supply a rod on bottom size both in
the small end and big end diameters. This is the way we police the sizing of
the rods to the right clearances. We are sure your engine builder knows how
to size rods, I.e crank journal + bearings being used and piston pin
manufacturer.
On to the most important issue, Unless you have a very short compression
height piston or very thick crowned piston, we cannot understand how the rod
will not rise up high enough to slide the pin in, since the small end
outside dia. is similar to standard rods. We suggest you source a different
type of piston in order to use the rods since these are the best rod you can
use in your engine, which is proven by whoo is using them. On the other hand
if the rod is too wide, we do this to put the pin in shear and not in
bending and allow for more bush area to prevent wear, if this is the case
why you cannot install the pin we suggest you modify the piston before the
rods.
Please feel free to post this information as it may assist & help other
persons as well.
Any further information please feel free to contact my self.
Best regards

Norrie Anderson

rob

 

[Odin]

and this:

Rob, Please read the email again, I think you missed the bit about
balancing. It is not about the over all weight on a set of scales. It is the
small end apposed to the big end as these preform different functions. If
you are still concerned please take my 1st email to your engine builder
before removing any material as this is not required.
Best regards,
Norrie

and this:

Rob, These are manufactured in batches of 4 from the same batch of material.
The end static weight over all is not technically important, this is only a
concern from a non engineering point of view.
Regards,
Norrie


rob

 

[Anonymous]

i cant wait to get the par gearset into my r..

i know there wont be any problems.

 

[campbellju]

1. the beam and 2. the big end. This is what we do,
we match all the rods to within 2.5 grams on the big ends which is what is
most critical in engine balancing and within 4.5 grams on the beam of the
rod. rob

So exactly what is matched to ± 1.5 grams!

We suggest you source a different type of piston in order to use the rods since these are the best rod you can use in your engine, which is proven by whoo is using them. On the other hand if the rod is too wide, we do this to put the pin in shear and not in bending and allow for more bush area to prevent wear, if this is the case why you cannot install the pin we suggest you modify the piston before the rods.

1. Who else with a Gti-R is using them?
2. First they say the rod can't be too wide but if it is...... we designed it like this so modify the piston.

He sounds like a nice helpful bloke but seems to completely ignoe the possibility of a quality issue. Just wait 'til I get my engineers report!!

Sorry to hear you're having a different nightmare to me at the moment. It looks more tempting to bin them again but I'm just getting done £140 of work to make the bearings fit and resize the bottom end. :roll:

Jim

 

[Odin]

I hope there ok Jim .



rob

 

[Nad]

just got this from Par.

We suggest you source a different
type of piston in order to use the rods since these are the best rod you can
use in your engine, which is proven by whoo is using them.
Norrie Anderson

Yes and thats why I am using Tomei stuff which was all spot on when tested at the engineers that balanced it and because it is balanced at Tomei's factory to a clutch of my choice for no extra cost. There was exactly 0% difference between any of the rods, now thats quality assurance. Lets just hope PAR dont start making cranks. TBH I have got fed up with the bull that comes out. Even the best gearbox builders in the UK have had to machine the gearsets.....oh but ur meant to, as its probably in the instructions because every standard gearbox is different :roll: ....

It would be nice for them to take someone to court, because then we will actually find out who is lieing.....and it certantly aint the customers. How many engineers reports will it actually take to convince someone...

Nad

 

[Jobi Joba]

A part from one of the rods being thinner, the internal diameters of one of the big end is also too small and will need to be machined. Specification is 51.000 - 51.013, actual is 50.846.

U lucky boy...mine were 51.025mm... :? At least I reckon they were ALL 51.025mm.But when too wide,u can't do anything.It seems their production is not really accuratene batch 50.846mm,another one 51.025mm :roll:

About the weight balancing,there was a difference of 4g between the lightest and heaviest rod of my set...

 

[campbellju]

Anyone who's attempted to fit the PAR rods had problems with centre to Centre distance? We thought we should have checked this before we pressed the pistons on but it is too late now unless I want to spend more money taking it apart again and checknig the rod.

Vpulsar, I noticed you had a problem in fitting the pistons, have you sorted this out yet and did you find out what it was? Was it the outside diameter of the little end?

Anymore "clearance gap" issues? How are people getting on?

Cheers,
Jim.

 

[skiddusmarkus]

Jim-my cas is at ADR motorsport in Chesterfield-you could ring and ask them what issues(if any)they had with fitting mine).

 

[campbellju]

Have you got a number handy for ADR? (Idf not I can probably find them myself)
and can you PM your real name so I don't ask for skidusmarkus car.

Slightly off topic (and a wild stab in the dark) but did you used to do track days in an MR2?

Jim