Dexta liners

[DextaJim]

Hi, Little bit of a Redneck question this, So, two years ago I rebuilt a Dexta engine and had an engineer shop remove and refit the dry liners, it was quite expensive and took a long time for them to get round to do the job, My question is are the "Finished liners" like the ones that Agriline stock, ok to use without the need to hone them after fitting, so the pistons will fit straight away, (assuming I can get the old ones out without too much trouble) wonder as well if anyone has done this,
Cheers Jim,

[Brian]

The "finished" liners are not really Dexta liners but are for the later engines. They do not press in tightly and are retained by a rim at the top so your block will still have to be machined/bored to take them then machined at the top of the bore for the retaining rim. They may still need honing when fitted.

Back in the mists of time, when we first started this board, one of the biggest problems we used to get was on Dexta and Super Dextas where liners had been fitted and not honed. I lost count of the number of engines that seized due to not being honed to size. My own feeling is get a machine shop to do the job whether you go for the later liner or retain the original style.

The reason for boring is to bring the liner back to size after it has been pressed into the parent bore. To hold it in place it has to be a very tight fit and the inner bore deforms as this is done.

[DextaJim]

Thanks Brian. that's the way I did my first Dexta, I thought with this one I could get away with just fitting new rings, Rings were bought which was when I realised that this engine had at some time been re-bored and over sized pistons fitted. I didn't realize people did that on these engines, I just thought they fitted new liners and pistons. ( so I have now in fact three sets of rings to fit a 3-144, ) ( and will get new pistons and liners) I asked the question because some, talk of using a bead of weld in the old liner to make it easy to get out and putting the new liner in a deep freezer to make it easy to get new ones in, am not a bodger so will have it done in the proper way, Thanks for the push Jim.

[russelm]

That is a reasonable method for removal/refit (need to heat the block and construct something to press the liners in) and if you are able to do it then it would save you money.

Once fitted they still need boring to final size and honing though plus also possibly the block decking to ensure the liners do not sit excessively proud of the block casting.

[DextaJim]

Thanks, I have been in touch with an engineer at Hull and they quoted £180 including vat and a turn round of 2 days, I think rather that try a DIY I will let them do it. I have to get the liners and was thinking Sparex, from Malpas. last time I had a Dexta block done the other engineers kept it 5 weeks. "well naft off I was"
not cheap these renavations on Dexta , lol. Cheers Jim.

[russelm]

Thanks, I have been in touch with an engineer at Hull and they quoted £180 including vat and a turn round of 2 days, I think rather that try a DIY I will let them do it. I have to get the liners and was thinking Sparex, from Malpas. last time I had a Dexta block done the other engineers kept it 5 weeks. "well naft off I was"
not cheap these renavations on Dexta , lol. Cheers Jim.

I got my engine kit from EMMMARK and was very pleased with it but, the bits all come from pretty much the same factories.