Jimbo's 855 T-5R Project

Jamest5r_

Well update time, was having a problem with excessive pressure in my block and it wasn't the pcv so after a compression test cold was good but hot was less, not good, pointing to a ring problem so strip down time, yes it might have been easier to remove the block from the car but I knew it could be done insitu so challenge accepted. Took me the best part of 10hrs to get to this point and I'll remove the pistons tomorrow. Looks like #1is burnt.

Jamest5r_

jamesinc

@Jamest5r_ is your bottom end stock?

Jamest5r_

jamesinc;c-160092 wrote@Jamest5r_ is your bottom end stock?

No forged rods and 81.4mm pistons

Ex850R

Jamest5r_;c-160093 wrote
jamesinc;c-160092 wrote@Jamest5r_ is your bottom end stock?
No forged rods and 81.4mm pistons

What CCs then?

Jamest5r_

If it was I would of just swapped enginge

Ex850R;c-160101 wrote
Jamest5r_;c-160093 wrote
jamesinc;c-160092 wrote@Jamest5r_ is your bottom end stock?
No forged rods and 81.4mm pistons
What CCs then?

2.3,plus a tiny bit more ?

360cf

Very impressive build Jimbo. The car looks great

Jamest5r_

Pistons are out and no obvious damage to rings or bores, which I suppose is a good thing but in a way I was hoping to see something broken to as why I had high crankcase pressure, head dropped off to be checked and new valve guides done, I'll await the results

360cf

Jamest5r_;c-160222 wrotePistons are out and no obvious damage to rings or bores, which I suppose is a good thing but in a way I was hoping to see something broken to as why I had high crankcase pressure, head dropped off to be checked and new valve guides done, I'll await the results

what ring gap are you running James? It looks like you are getting some blow-by past the top compression rings

Jamest5r_

360cf;c-160253 wrote
Jamest5r_;c-160222 wrotePistons are out and no obvious damage to rings or bores, which I suppose is a good thing but in a way I was hoping to see something broken to as why I had high crankcase pressure, head dropped off to be checked and new valve guides done, I'll await the results

what ring gap are you running James? It looks like you are getting some blow-by past the top compression rings

That's the least of my worries mate....

Bores 1&5 are cracked so that's a scrap block.

Time to build this one up with the h beam rods.

Ex850R

Are you sleeving the liners next build?

360cf

I find it amazing how vulnerable these blocks are considering they were designed for high cylinder pressures

Jamest5r_

Ex850R;c-160266 wroteAre you sleeving the liners next build?

Nope

Jamest5r_

360cf;c-160267 wroteI find it amazing how vulnerable these blocks are considering they were designed for high cylinder pressures

I had a fuel pump issue back in the UK, it ran lean a couple of times, I thought I'd got away with it but obviously not, they are strong blocks but very susceptible to heat

Jamest5r_

360cf;c-160267 wroteI find it amazing how vulnerable these blocks are considering they were designed for high cylinder pressures

The weakest point is the standard chocolate rods, they will bend with ease with too much torque under 3k rpm, my engine survived 7yrs of 28psi on a mbc and 30ks, most on the 1/4 mile and some hill climbs, it had a hard but fun life

360cf

Jamest5r_;c-160270 wrote
360cf;c-160267 wroteI find it amazing how vulnerable these blocks are considering they were designed for high cylinder pressures
The weakest point is the standard chocolate rods, they will bend with ease with too much torque under 3k rpm, my engine survived 7yrs of 28psi on a mbc and 30ks, most on the 1/4 mile and some hill climbs, it had a hard but fun life

Yes you did well. I've owned 3 volvos and all had cylinder head/ gasket issues with the exception of my current (forth). Those were all unmodified and well maintained. If you browse through Gumtree etc you will find one Volvo after another with "suspected blown head gasket". I agree regarding the rods, and high cylinder pressures at low rpm will bend rods and bust gaskets, so in their wisdom they used weak rods, very thin sleeves and a turbo designed for peak boost at 2,000rpm. Your motor did well, but they can be frustrating

P.S, perhaps that is why I was seeing blowby on your top rings...the cracks in the bores

Jamest5r_

360cf;c-160272 wrote
Jamest5r_;c-160270 wrote
360cf;c-160267 wroteI find it amazing how vulnerable these blocks are considering they were designed for high cylinder pressures
The weakest point is the standard chocolate rods, they will bend with ease with too much torque under 3k rpm, my engine survived 7yrs of 28psi on a mbc and 30ks, most on the 1/4 mile and some hill climbs, it had a hard but fun life
Yes you did well. I've owned 3 volvos and all had cylinder head/ gasket issues with the exception of my current (forth). Those were all unmodified and well maintained. If you browse through Gumtree etc you will find one Volvo after another with "suspected blown head gasket". I agree regarding the rods, and high cylinder pressures at low rpm will bend rods and bust gaskets, so in their wisdom they used weak rods, very thin sleeves and a turbo designed for peak boost at 2,000rpm. Your motor did well, but they can be frustrating

P.S, perhaps that is why I was seeing blowby on your top rings...the cracks in the bores

Maybe re the rings, I haven't pulled them off yet to see it the cylinder is cracked underneath, funny that alot of the blocks here suffer head gasket failure it's not as nearly as common in the UK don't know why maybe the ambient temps has something to do with it and pushed them over the edge?

Samman88

Interesting tear-down!
I have no personal experience in doing this but I've read of people having good, cheap success using some shim stock between the bores on these blocks. Perhaps less of a thing with the 2.3 than it is with the 2.5.

Jamest5r_

Samman88;c-160275 wroteInteresting tear-down!
I have no personal experience in doing this but I've read of people having good, cheap success using some shim stock between the bores on these blocks. Perhaps less of a thing with the 2.3 than it is with the 2.5.

Not necessary on the 2.3 blocks, I just unlucky with it running lean.

timbo

Its probably worth throwing some shims in as its cheap and you have the head off anyway.
Im surprised it wasn't spewing coolant out of the coolant tank under boost with 2 cracked liners was your coolant level dropping at all?

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