Hey guys..right this is my first post on here...i hope i wont get flamed to much as im not acaully a 6/rallye owner..but have signed up to see if i can get any advice / info for my 306...

Just as a quick hello, im basically on several other 306 related sites, and drive a black ph1 D Turbo, fairly well known car on some other sites, have done a fair ammount of work to it engine wise..

Now the reason for signing up, i have recently been pushing things quite hard (hybrid turbo, front mount and lots of fuel pump changes and piper cam makes this very hard to overdo lol...) and basically its thrown a rod out the block...now, alot of people are saying ive just had some freak bad luck, as the xud9 cant take alot of abuse, but i dont want to rebuild it, to see the same happen again.

It would appear that was acaully failed, was the bolts holding the rod to the crank...now what im after, is to see if i can get hold of some arp bolts for this, does anyone know if the bolts are the same on a gti6/s16 as on an XUD?

And does anyone have any advice on how i can avoid this happening again!

Thanks for your time, and a few pics just to show you the car in question..

No...d8b...so shud be safe from dodgy rods in the first place right?

what phill said

I think it was dodgy rod bolts not rods that affected the DHY, though my brothers one is on 160k+, but has been serviced very well and is not tuned.

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Bring on the Trumpets.

Yeah, but they're dropping the static compression so far the car has about as much pull as a pensioner in a miniskirt until it finally comes on boost, and shocking fuel economy to boot, as the mixture has to be immensly rich low down to get it to light off.

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seen a 1.9 td running 100bhp nitrous jets and 100bhp propane jet (extra fuel) with 45psi boost on standard bottom end with no problems. couldn't someone measure a 6 bolt for the guy. or anyone got an engine parts book should be listed in there.

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that car looks sweet , what sort of bhp wos you running before it went bang ?

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Ok, pulled the engine out this evening, and didnt really have time for examination, but can clearly see in one of the huge holes in the block, that the big end is still on the crank, so the bolts did NOT fail...conrod has snapped in 2...faulty rod?

Possible a bad bearing could cause it over time?

To much power acaully able to cause this from it?

What do consider to be "over revving it", i dont genrally rev it past 4500rpm... but it will hapilly pull to 6k with the gov shimmed and the piper cam....

I think you've found the reason why most diesels make loads of torque at 1500-3000rpm and don't rev past 4.5-5k as standard


wonder what the dynamic compression is like with 21.8-1 and 30 psi of boost?


Rich only runs 1 bar for 400 bhp right? at about 8.5-1?

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need a part number? get on here - http://public.servicebox.peugeot.com

Bring on the Trumpets.

Connecting-rod loads - particularly big-end bolt loads -are more a function of RPM than power. The tensile force on the big-end bolts increases in relation to the square of the RPM I think.

For example, if you increase your rev limit from 7000 by 10%, to 7700, the tensile force on the big-end bolts increases by 21%.

I would need to check a book at home but I think that's right, and gives you an idea of what over-revving does to rods.


Having said that, your big-end is intact, so I wouldn't say over-revving is the problem.

Does the big-end still spin freely on the crank, or is it seized / bearing damaged in some way?


If it's seized, the big-end bearing has failied, which would have pre-empted the rod snapping.

If the big-end bearing is OK it will of probably snapped due to fatiguing over time, caused by the shock loadings from the extremely high cylinder pressures, and the 'diesel knock' style combustion which isn't particularly smooth.

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07732 822546

The bearing seems perfect...just snapped in 2...

Stuck with what to do, whats the point in just building it up agen on a new block, itl just happen agen...

Lol, if you knew me, you would know that getting a 6 isnt an option

Nice thread this, good to see no flaming going on, i suspect that is however to do with the excellent first post

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