Update on 315 exploding engines.

I did my apprenticeship in 1996 and at that time I still don't think there was much torque to yield stuff around then. Since my last post the supplier for the big end bolt has cancelled my order as there are no bolts in the country. I contacted the dealership and they have only some of the bolts I needed at $15 each out of Melbourne. They even wanted $208 for a rear main oil seal (with housing). According to the WIS, the bolts for the mains and big ends can be used if they do not exceed 63.8mm for mains (Big ends I would need to look up again) My bolts are around 63.2mm on average but Im not going to risk using them again. Now I am likely to have my bearings delivered tomorrow and no bolts. The search continues
 

Midwestdrifter

Engineer In Residence
I cannot understand why they fixed something that was not broken with the introduction of torque to yield bolts
Because they are superior in every way. But if you enjoy a head gasket job every 5 years, go for it. The other method is too inconsistent for engines that make 100hp per liter.
 

blackjackmac

New member
There is a place in Taree with mountains of fixings. If you dont find it on Google i will find it for you. Cubic inches is the safe way for performance, with every part built to take the load.
 

blackjackmac

New member
Head bolts yes where there is compression of gasket and aluminium head. I would rather high tensile self locking bolts of same diameter where cap and block are solid. As you point out these engines are delivering sledge hammer blows on either side of intermediate brgs. I dont think bolts designed to yield can take that punishment without going up in diameter.
 
I did manage to get the bolts that I needed but had to go genuine. I got new main cap bolts and conrod bolts which cost me around $180. Although the crank measured OK I had it ground undersize by. 25mm due to pitting on the bearing surfaces. I have since put the engine back together ready to go back into the van. I ended up changing the front crank seal, oil pressure relief valve, rear main, and timing case seals along with the oil cooler seals. The pistons were all replaced which was the due to original issue. Hopefully with only 160k on the original build I should have lots of life left in it yet.
 

Attachments

blackjackmac

New member
I bet you miss working on those steam engines
Steam???. that was just coming into vogue after my retirement. I can offer you my understanding of the Carnot principle. My tribe could not come to grips with turning reciprocating motion into rotary motion. that lead us to inventing the wheel.
 

blackjackmac

New member
I did manage to get the bolts that I needed but had to go genuine. I got new main cap bolts and conrod bolts which cost me around $180. Although the crank measured OK I had it ground undersize by. 25mm due to pitting on the bearing surfaces. I have since put the engine back together ready to go back into the van. I ended up changing the front crank seal, oil pressure relief valve, rear main, and timing case seals along with the oil cooler seals. The pistons were all replaced which was the due to original issue. Hopefully with only 160k on the original build I should have lots of life left in it yet.
 

Top Bottom