Porous Block

[smo17003]

I have had my engine block sleeved back to standard but upon pressure testing it is now found to be porous in one of the bores. The engine reconditioner is now sending the block away for a chemical sealing process. The process is called Ultraseal and there is a web site - ultraseal.co.uk - that explains the process. My question is, does anyone have any experience of this type of repair?. The reconditioner, who has a very good reputation in classic engine repairs, says that the repair is more common on aluminium heads etc., but that he has had a few iron blocks done without any problem. The block is an early, non-L, specimen.

Cheers

Mike

[chrishewett]

Mike,
How oversize were the bores before resleeving? These blocks can't take much boring out. If you paid anything like most engine rebuilders charge for the job you may have been better off buying a good used L block on ebay, there have been a few sold recently. I would consider cutting my losses at this stage, I don't think I would trust putting the block back in the car.
Sorry to be depressing.
Chris

[GrUmPyBoDgEr]

Hi Mike,

Ultraseal is a very well known process & widely used in the Automotive industry, even on new aluminium castings, to reduce porosity.
I can see no reason why it should not also work on iron parts.
I expect that the block will be properly cleaned & degreased prior to Ultrasealing.

Good luck
John

[types26/36]

I have had my engine block sleeved back to standard but upon pressure testing it is now found to be porous in one of the bores. Mike

Mike,
I dont quite understand what you are saying, if you have had new sleeves fitted into the block (to bring it back to standard) then why would the new sleeves be porous? ....the new sleeves should be thick enough to allow at least one more rebore after finishing to the original size (82.55)
The block is bored to suit the outside diameter of the new sleeve, the sleeve is then pressed in and sealed at the top and bottom, are you saying that the actual bore is porous or the top or bottom of the sleeve is not sealing?

[denicholls2]

If your (brand new?) sleeves are bad, the corrective action is to replace them with good ones, not to rely on a chemical process to fix a fault that shouldn't be there. From your description, the sleever botched his job. If he makes it right, you have no need to worry about sealing.

I for one would not let him fix his bad work other than by redoing it, or paying someone else who knows how to do it correctly.

If, on the other hand, your porosity is in the head to sleeve seal, that's another matter. But it isn't what you implied, and it would involve the alumin(i)um head and not the iron sleeves.

[smo17003]

OK, the reason for sleeving the block is that it was already on +40 and so a sleeve job and a set of standard pistons (?40.00) from Miles Wilkins seemed more cost effective than finding another block (?250.00?) and a set of overpriced pistons (?400.00?).
I won't name the reconditioner, but I will say that they have - according to their web site - many happy customers who drive Bugatti's and Aston Martin's. Slightly more exotic than a simple "Ford" lump. They specialise in head work and actually do T/C heads for some of the more well known Lotus "specialists".
The reason I use them is because I get a very good price due to my trade connections.
When I mentioned your "concerns" to the guy today he explained that it is a parent bore that is porous at the top or the bottom - this is all new to me as well so I don't profess to fully understanding his explanation - and not through the new sleeve. It is their standard proceedure to re-pressure test after fitting new sleeves.
At the end of the day, the block might still come back from Ultraseal and be no good; but my view is if these guys are experts, let them do what they think is best. If he wasn't confident that the process works he would have asked me to find a better block. If it works, then we've all learnt something.
I must repeat that this company - not a one man band - has a very good reputation to uphold and to do a botch job is not in their interest.
But just in case I'll look out for another block at Stoneleigh.

[StressCraxx]

I have had this sealing process done to a 711 block in my Formula Ford. No issues at all.

Cast iron is thermally and dimensionally much more stable than aluminium.

[chrishewett]

I have a "one man band" do my engine work and I can most certainly say that the work is second to non. My block was already bored +60 and relined very succesfully. As it is a big valve head, Miles Wilkins standard pistons are no good so it was bored for oversize pistons straight away. The job was properly done and if there had been any problems due to the engine rebuilder he would have taken responsibility and not tried to take more money from me to put the job right in another way. There is only one way to do any job.
Engine work on Bugattis and Astons is no different to the " humble Ford lump".
My advice ( I am sure it is not wanted) is, find another engine rebuilder.
Chris

[smo17003]

Chris,

Please tell me why Miles Wilkins pistons should not be used? Quite a few people on here have said that Miles does these pistons at ?10.00 each. I've yet to see a post saying "don't touch these pistons with a barge pole".
I used the phrase "one man band" because I got the impression that you guys thought that I was using an amatuer repairer. I did not intend to imply that the smaller workshops did anything less than a good job.

Mike

[chrishewett]

Mike,
I looked at the Miles Wilkins pistons and there is nothing wrong with them, he bought 500 sets from Lotus when they cleared their old stock. However, they are for the standard engine not the big valve. My engine man said he may be able to machine them to clear the valves but this would involve assembling, measuring, stripping, machining and reassembling. Even then he may have had to take off to much metal. Reluctantly I decided to go for the much more expensive oversize pistons from QED.
Incidently, I understand that QED have shut their workshop and are not rebuilding twincams anymore. Miles Wilkins charges ?5000 for a rebuild. It really is getting more difficult to find a good man to do the job.
It makes the rebuilt twincam on ebay going for ?2500 a good deal.
Chris

[tdafforn]

Hi chris,
Was there any particular reasoning behind choosing QED pistons above others such as burtons?
I'm embarking on rebuiling a 711M bottom end and the next purchase is pistons. Burtons seem to do a good range, including one set designed for a 1700 711m conversions, but i have no idea of which type to go for!
cheers
tim

[smo17003]

Chris,

My head is the standard variety so, hopefully, the pistons will be OK.

?5000 does seem a lot for a engine rebuild. Is this to standard spec. or something special? The engine on Ebay has now gone above ?3K. At these prices dropping in a Zetec or similar does seem more attractive, especially if you intend to use the car as a daily driver. I know that this is probably sacreligeous, but I can see some owners having to take that route when faced with paying ?5K for an engine that will probably either do minimal mileage i.e. a show car, or an engine that will need another rebuild at 50K miles.
Personally, I've always assembled my own engines myself after having the machining done, which obviously keeps the costs down. It also gives you immense satisfaction when it's up and running OK.

Mike

[steveww]

If QED are no longer doing lotus twin cam engines there are still plenty of other good engine builders around. There are still plenty of twincs running in classic racing.

Try http://www.wilcoxengines.demon.co.uk/ who specialises in historic racing engines. I like the idea of his 2.2 twinc in my S4

[chrishewett]

Tim,
No reason except that my man always uses them and I didn't bother to look around. He has my 1700 711m conversion in at the moment for a strip down to assess what needs to be done. I am hoping not much. If it needs new pistons I will look at the Burton option. Are they forged?
Mike,
Miles says that his rebuilds will last a lifetime! However, he says you must use a lead additive and that all troubles are caused by people using modern fuel without additives. Who knows what to think.
Steve,
I agree! Very impressive!
Chris

[tdafforn]

Hi Chris,
the pistons are forged from Accralite..117.50 each in VAT (Ouch!)
Only trouble I am worried about is that they claim they give a CR of 11.6:1. Isn't this a bit high?
The comparable OE pistons are cast and 9.5:1 and cost 99.50 each
Otherwise there are Cosworth equivalent forged at 690.00 a set giving a CR of 12.0:1
What do you recon?
Tim