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#1 Casting block
Posted: Wed Jan 10, 2024 11:56 am
by heathcot

Hi
I have managed to obtain a short stud block for my 66 roadster which has the original head but a later long stud block.
It is in excellent condition standard bores, crank etc but in certain lights there appears to be a raised patch(no stitch marks) giving the impression of a slight crack. There is a mirror image although not as raised on the front too. I have poured evaporated into the water jackets and there have been no leakage.
Do you think these are casting marks or signs of a previous repair? Can I get the block pressure tested?
Thanks for reading
Regards
Paul
#2 Re: Casting block
Posted: Wed Jan 10, 2024 2:11 pm
by bitsobrits
I believe those marks are simply remnants from the casting process, but I understand your concern. I would always recommend magnaflux crack testing for parts of unknown provenance before using them in a build. It's fairly inexpensive, but a bit of hassle to get the block to/from a shop. Alternatively, there are various crack testing kits available for DIY use, though I've no experience with them.
#3 Re: Casting block
Posted: Wed Jan 10, 2024 3:30 pm
by DWW
Initially you can grind it down with a brass wire brush either manually or on a drill to get a clearer picture of what you are looking at under the surface rust/crud.
#4 Re: Casting block
Posted: Wed Jan 10, 2024 6:39 pm
by heathcot
Thank you for your replies. It was odd as it seemed raised and I wondered if there were examples of this block type cracking at these points.
The whole engine was exceptionally clean and kept as a spare for at least 20 years by the po
I will look into the test suggested
#5 Re: Casting block
Posted: Fri Jan 12, 2024 12:59 pm
by heathcot
Well some bad news…..only in certain lights a crack shows up along the edge of the head/water jacket
Not sure how deep but definitely some attempted repair in the past
Tried to contact stitchweld but it appears they are no longer in business?
Anyone seen anything like this before?
Cheers Paul

#6 Re: Casting block
Posted: Fri Jan 12, 2024 2:49 pm
by JerryL770
I should think Surelock (now part of Project Heaven) could fix that.
www.castingrepairs.com
#7 Re: Casting block
Posted: Fri Jan 12, 2024 7:45 pm
by Phil P
Hi Paul,
I had my block laser welded by Harrison Laser Technology at Scunthorpe. The crack was in the bore revealed once the liner had been removed and access for a stitching process wasn't possible. Unlike conventional welding of cast irons that require high pre and post heats and inevitable lead to significant distortion, laser welding heats such a small volume due to its intensity that distortion isn't an issue. They also did a great job on my brass quarter light. The last time I was there they had a Triumph Gloria which was having a crack in its block repaired in-situ. It might be worth considering if Surelock can't do it; although I suspect they will be able to repair the crack shown in your photo. You might ask them if it's Ok to stitch on a sealing surface. Following the welding I had my block impregnated as a belt and braces measure.
https://harrisonslasertech.co.uk
Yours,
Phil
#8 Re: Casting block
Posted: Sun Jan 14, 2024 4:16 pm
by astonman
Got any more info on the cost of laser welding and impregnating the block?
Who did you use for the impregnation process? ultraseal?
#9 Re: Casting block
Posted: Sun Jan 14, 2024 6:23 pm
by sulzeruk
I just had my 65 FHC blockl acid dipped to clean out the waterways, when i got it back there was 2 patches either side of the centre core plug that looks like where the casting sprues have been ground off. Looks to be in the same place as your engine.
#10 Re: Casting block
Posted: Sun Jan 14, 2024 6:32 pm
by bitsobrits
Paul,
That crack almost has to be from a freezing incident, as it would be extremely unlikely for that fracture to occur in normal service or as a result of an original casting issue. That suggests to me that a full professional cleaning and inspection of the block is warranted before spending money on repairs.
#11 Re: Casting block
Posted: Tue Jan 16, 2024 9:57 pm
by heathcot
It’s going for an X-ray tomorrow, Wednesday
Had a quote of 3k estimate for fusion welding which seems high to me
Thanks for replies
#12 Re: Casting block
Posted: Wed Jan 17, 2024 7:28 pm
by Phil P
Hi Paul,
I think the orientation of the crack may mean that X Ray may not show much. Mag particle would be better and possibly ultrasound. £3k seems an enormous price for the welding; my laser welding cost £500.
Yours,
Phil
#13 Re: Casting block
Posted: Sun Jan 21, 2024 1:32 pm
by Mark Gordon
I had never heard of laser welding until I read this thread. I looked it up and was interested in finding out which laser and what settings (wattage, pulsed vs. continuous wave, etc.) are used for welding. Interestingly, the Nd:YAG laser is the generating source. As I'm sure all on this forum know wavelength (1064 nm for the Nd:YAG) and power output (wattage) are the main determinants of what the laser will do. By adjusting those and other factors, the Nd:YAG can be used to tack down a detached retina, selectively remove unhealthy gum tissue while leaving the healthy tissue unaffected (my area of expertise), welding metals or even as a military weapon like the US Navy is developing for shooting down various aircraft. Amazing stuff.
#14 Re: Casting block
Posted: Sun Jan 21, 2024 3:11 pm
by paydase
The big advantage of laser welding is that it can be more focused than TIG. Hence useful for very localised repairs.
Its relative disadvantage is that it costs more to get the same power and that more power may be reflected/non absorbed by metal compared to TIG. So usually a tool used/owned by professionals.
#15 Re: Casting block
Posted: Sat Feb 03, 2024 12:28 pm
by heathcot
Just to inform you of the progress
The block has been Magnafluxed and bitsobrits was spot on in the fact that both the original photos were casting marks (also pointed out by sulzeruk) and an (older, experienced) engineer's assessment is the top cracks are the result of freezing not overheatingH
He had seen this damage on xk blocks before and said stitch locking was quite sufficient to repair it. He felt that welding was not a good idea due to the heat impact on the rest of the block. No doubt a high tech solution could mitigate the heat issue
Will keep you informed of the outcome. Thanks again for your interest and comments
Paul