Dexta Block

[Super D]

All - been offered a Dexta block can someone confirm that this block can be used as basis to ''build'' a Super Dexta engine. My Super Engine has a crack in usual place.

Also what's acceptable price to pay for block / engine

Thanks

[YorkshireDextaMan]

Have to leave the value to someone else. But i am fairly sure a Dexta block will re-sleave to make it Super spec.
Perhaps this is not relavant, but make sure it is a Dexta block, and not a 3cyl Perkins block as fitted to MF 35 s and some others. because the rear main bearing cap is different and a Dexta sump may not fit. Think i am right on that ???? . Jim

[Jerry Coles]

IMHO A dexta block can be re-sleeved to 3.152 size (I think thats the only option available in sleeve size/rebuild kits nowadays) from a 3.144. Its the thickness of the sleeve wall that denotes capacity.
I bought a 'Dexta' block from Agriline and after contacting them regarding the non-fitting sump they said that it was in fact a MF/Perkins block which required '"some work" to make it Dexta compatible. This I quote from their managing director who I manged to speak to. Apparently "I should have been informed" when the purchase was made. I was offered the chance to return the item but when you have spent time painting, fitting camshaft, timing covers and gears etc and doing the work listed below you don't want to end up back at square one without an engine so I bit the bullet.
This entailed removing some mass off the rear Main Bearing cap to allow the Dexta sump to fit. Some time with an angle grinder and a good clean down after and it's OK. It is a pain having to keep offering a quite heavy sump up to the underside of the engine to check clearance.
The other problems were:
A Having to blank off the end of the camshaft where a MF has the tacho drive pick up fitted.
B Blanking off the side port where the camshaft drives the MF fuel lift pump
C Fitting bolts/plugs to tapped points in the lower front of the block oil gallery
These task were not difficult, just the frustration of not quite getting what one assumed was as advertised in the catalogue.
This was my experience and the engine starts and runs fine giving a new lease of life to my Dexta.
Just the brake cross shaft seals to replace now and she's nearly leak free!

Jerry
Bath
UK

[GERRY]

Regarding price for block , new block in around £400 used block which is over 40 years old
between £50 and £150 depending on bargining skills, not forgetting one that hasnt cracked is
stlll prone to , remembering it is only worth what the buyer is prepared to pay and
how much you want or need it, also having no come back if something goes wrong with it'
just my half a cent worth GERRY

[Tubal Cain]

The outside diameter of the Super Dexta liners is a few thou larger than those for the Dexta, so the block would require to be bored out after removing the old liners; plus the new liners will require to be fitted and finish bored. An expensive exercise.

I have a sound Dexta block which I wish to use as a replacement for a cracked Super Dexta block. My intention is to have the Dexta block bored out to suit the larger pistons which will eliminate the cost of removing the old liners and fitting the new. The only give away will be the engine serial number, as Dexta engines start 14xxxxx whilst Super Dexta engines start 16xxxxx.

Jerry came up with some interesting revelations regarding the replacement blocks! Considering their cost and the fact that they require to be modified in order to fit the sump, it may be a viable option to have the four damaged blocks which I have and intended to scrap, repaired by metal stitching.

Gerald

[YorkshireDextaMan]

Gerald, you said. "The outside diameter of the Super Dexta liners is a few thou larger than those for the Dexta, so the block would require to be bored out after removing the old liners;" Well thats news to me, mine was a standard Dexta block, and no one bored the block out on it to fit Super Dexta sleaves. the new sleaves have to be honed for the new pistons, but that was it. As a post script , the old Dexta liners whilst remaining in the block, can be bored to SD size , perhaps this is what you mean ??
Jim

[Tubal Cain]

Jim,

Iwas quoting from the engine spec. sheet which shows that the outside diameters of the liners are different. It also states that the unfinished liners require some 0.040” to be removed after fitting to give a bore of 3.600” which would require more than just honing. The replacement liners supplied by one of the major suppliers have an unfinished bore of 3.570”! Which suggests that the liners fitted to your engine were already bored to size.

I did state in my post that it was my intention to have a Dexta block bored out to accept Super Dexta Pistons. By which I meant that the liners would be bored out to 3.600” to accept the larger pistons.

Gerald