×

Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Open deck liner measurements

General Engine Building Discussion

Forum Posts

Courses

Blog

Tech Articles

Talk about engine building here. New products, tricky questions or showcase your work - If it's engine building related it's welcome here.

= Resolved threads

Author
191 Views

Hello,

I am building an engine with an open deck with wet liners. I measured the new liners using a dial bore gauge and I had out of round measurements varying from 0.0005” to 0.002” across the 4 cylinders. They were fitted into the block and gently clamped down to stop them from coming out.

Due to it being an open deck (aluminium block), using a torque plate or the cylinder head, I can’t imagine it pulling the cylinder out out shape as the bolts are not in direct contact. The liners do protrude out of the deck, would clamping them down with a head, possibly bring them back into shape.

Would you say it is worth torquing the head on and measuring the liners from underneath to see if it pulls the liners round? Or would I be wasting my time and they just need re honing?

Also, when using torque plates or temporarily fitting the head for these measurements. I would want to use the head gasket and bolts I would be using on the final assembly. But I would not want to compress the head gasket and stretch the head bolts and not be able to use them again. Would you recommend using older bolts of the same spec and a head gasket that has already been used?

Thanks in advance!

I was hoping someone with relevant experience would have commented 'fore now, but as that hasn't happened, my 5p worth - which may be about what it's worth.

It's not clear where the liners are out of round, but I would have 100% expected the liners to be manufactured so they were actually round - especially if they were supposed to be finished to size. Was it just installed they were out of round, or when they were free standing off the engine?

If it was the former, it may be the block that's a little out of shape - have you tried them with the main bearing caps installed and torqued, as that may move things around a little and possible correct things - or not?

If it was the latter, or both, there's little that can be done other than trying to return them for "round" liners or machining/honing them to round - or at least so the minimum diameters match the clearance(s) for the pistons.

As you surmise, as they're 'free standing' the bolts/studs used for the head will not distort the liners as there's no contact, and a torque plate/fitting the head shouldn't have any affect either, as they'd be loading in line with the liners. Actually, IIRC, the old air-cooled VW beetle engines had a recess in the heat the liners slipped into, which 'might' affect things if it was an interference fit.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?