smoke on over run :-(

gelmonkey · Post by **gelmonkey** » Sun Mar 14, 2010 10:43 am

Tony
Have only just seen the damage to your motor and can do nothing to help you right now but can totally understand how you are feeling.
I spent two years rebuilding my car in a former guise and the first time out it caught fire and destroyed the front end.This was down to an expert? who had set up the carbs and the throttle linkages.Strange but I never went back to him
If I can help you in any way possible just give me a shout and I will do my very best.
DON'T GIVE UP MATE.
We're all feeling for you.
cheers
Paul

DEVONMAN · Post by **DEVONMAN** » Sun Mar 14, 2010 10:51 am

thev8kid wrote:Hi Denis,
looks like i was told an expensive porky then,

cant remember there being any arrows on the crowns, but will double check later,
but looks like we have found the problem though,
thanks mate.
werid why its only 2 cylinders and not all 8 that have picked up on the pin.

looking at getting the block relinered on the buggered two,
and hunt down another set of 4.0 pistons and a set of 4.6 rods,
oh the fun never ends eh

Could be that the pins in no 4 & 8 were not pressed in to exactly the centre of the rod.
It is unlikely the the pins have moved in the rods as they are a megga interference fit. ( unless someone has abused them in the past)

It will be interesting to see if the big end bearings of no 4 & 8 show any signs of a side uneven loading.
Cheers Denis

bclancy · Post by **bclancy** » Sun Mar 14, 2010 11:00 am

Hey coops

I'm pretty sure it wont be any good to you, but I will have a spare 3.9 block/crank rods in a few weeks once I pull it out. The block seems to be fine, no overheating but cant inspect as still in car at the moment. I was going to use it to play with but if any bits or all of it could be cobbled together to get you going for now with the salvageable parts from yours your welcome to it gratis. Sure we can find a way of getting it to you somehow? Anyone else got any spare bits?

Best wishes

Brian

Post by **katanaman** » Sun Mar 14, 2010 11:31 am

Sorry to see this T that's a real PITA. I would tend to agree with Denis, it does look like two of the pins aren't pressed in properly. Course there would need to be something else involved to make the rods want to sit so far to the side as well I think. A fill strip down will reveal all no doubt.

Post by **Coops** » Sun Mar 14, 2010 12:09 pm

cheers m,
Just checked ALL arows on crowns are facing the front, will upload pics when home,
So pistons are the right way round, phew... Was doubting myself then

DEVONMAN · Post by **DEVONMAN** » Sun Mar 14, 2010 2:22 pm

thev8kid wrote:cheers m,
Just checked ALL arows on crowns are facing the front, will upload pics when home,
So pistons are the right way round, phew... Was doubting myself then

Before you unbolt the big ends check that the con rod is central in the piston.
Cheers Denis

Post by **Coops** » Sun Mar 14, 2010 3:41 pm

ok will do mate.

Post by **Coops** » Sun Mar 14, 2010 7:49 pm

Hi Denis,
checked the conrod and indeed it was central within a few thou,

i will let the following pictures explain what we found

Side 1 of piston 4,

Side 2 of piston 4:

This what happened to piston 8 when we removed it,
the pin fellout on its own,

Shite pic of the bores,

another shite pic of the fooked bores,

DR JONES · Post by **DR JONES** » Sun Mar 14, 2010 7:56 pm

hi, who fitted the rod's &pistons?

Post by **Coops** » Sun Mar 14, 2010 8:09 pm

I bought them off a member on here who had them done,
im not going to make the company name public as im not like that,
I can only take the sellers word that the said company did them,

ppyvabw · Post by **ppyvabw** » Sun Mar 14, 2010 8:14 pm

Has it shagged the pistons mate?

Would you get away with a couple of new liners (or even all eight top hats) and some new rods/pins, whichever is at fault?

Post by **Coops** » Sun Mar 14, 2010 8:21 pm

pistons seem fine,
pins shagged, and it looks like the pin end also shagged on rods,

im thinking about getting another set of 4.0 pistons and getting the reliefs cut proper this time,
i have my old rods that came with the new engine when we got it,
so we could use the rods and pins from there if need be,

Ian Anderson · Post by **Ian Anderson** » Sun Mar 14, 2010 8:44 pm

Were there not circlips in the pistons to stop that happening?

Ian

topcatcustom · Post by **topcatcustom** » Sun Mar 14, 2010 9:06 pm

Ian Anderson wrote:Were there not circlips in the pistons to stop that happening?

Is that not only with floating pistons?

DEVONMAN · Post by **DEVONMAN** » Sun Mar 14, 2010 11:15 pm

Ian Anderson wrote:Were there not circlips in the pistons to stop that happening?

Ian

RV8 pistons don't have circlips as the pin is a tight interference fit in the rod end. In the case of Tony's rods the interference fit was inadequate and the pins drifted off centre and damaged the bore. Who knows what the history of these rod is but all 8 will need chucking to ensure a non repeat of the problem. Maybe the rod end has cracked due to overheating and sudden cooling during pin installation but I am guessing here.
Cheers Denis