I am about to have my original engine rebored, I am doing a full renovation on it. I am having the block chemically dipped to remove all the crud, inside and out. My question is:- What sort of primer (if any) is needed prior to repainting in BMC engine green? I once read that the internal galleries were also primed, is this so? I guess the surfaces will need to be treated immediately on removal from the dip, as presumably rust will start setting in?
Any help gratefully received as always!
I would worry about the 'dip' process - why do this ? Just wash it all down with paraffin - and squirt some through the oil galleries. I find the paint binds on to the engine ok (provided properly degreased) - without any fancy priming.
I would worry about the 'dip' process - why do this ?
Reading the spec for a recon engine from one of my suppliers, they mention that the engines are chemically dipped, so I assumed that it would be wise to do likewise and thoroughly clean it all out prior to rebuild. I didn't want to risk having dislodged ancient deposits giving the re-born engine a coronary!
Owns: Skoda Citigo
1968 Morris Minor Convertible[sig]3739[/sig]
It's up to you!! Never found this necessary myself - and never had any problems with paraffin. And I have built many high power and successful A series engines over the years!
Is it rebore AND crank re-grind ? Not that it makes any real difference to the above advice - but pipe cleaners are good for getting any left over grinding gunge out of the crankshaft oilways. Be sure to get a new oil pump - and check/clean the oil pressure relief valve.
It is indeed, the full monty! New cam and followers also. Reckon new pushrods would be a good idea too? Oil pump is already near the top of the list of items to buy!
No - pushrods go on for ever - unless they get bent of course. Are you upgrading the cam ? If so (MG Metro cam is good - needs matching oil pump) consider duplex timing gears and chain - and try to get hold of a crankshaft damper.
If you're spending decent money then don't scrimp by avoiding the dip process. This removes the rust, rot and sludge from the cooling ways and helps bring the block back to a 'new' condition.
Ray. MMOC#47368. Forum moderator.
Jan 06: The Minor SII Africa adventure: http://www.minor-detour.com
Oct 06: back from Dresden with my Trabant 601 Kombi
Jan 07: back from a month thru North Africa (via Timbuktu) in a S3 Landy
June 07 - back from Zwickau Trabi Treffen
Aug 07 & Aug 08 - back from the Lands End to Orkney in 71 pickup
Sept 2010 - finally gave up breaking down in a SII Landy...
where to break down next?
2013... managed to seize my 1275 just by driving it round the block
Although you have been told that new pushrods are not needed, do check the bottom convex faces, as they tend to wear and leave a 'pip' in the middle. In some cases this can be removed with an oilstone if it's not too bad. This pip wears in conjunction with the cam followers and in theory parts that wear together should be replaced together, in good engineering practice. This has to be a balanced view as it can be never ending!
BM I am using a new old stock standard cam, but will be following your earlier advice re using a 4 degree offset key for the cam timing. Duplex chain is planned also.
Ray, I'm still considering the dip, will discuss with my local engineers (Redmans of Fleetwood, very good reputation, seem very knowledgeable too)
Les, I will take your advice re stoning off the pips, though does this remove any localised case hardening? I'm using new cam followers along with the new cam.
If rebuilding an engine I would always give the block a good cleaning whether this is chemical, steam cleaner, presure washer or degreaser and a hose pipe. I always knock out all the oil way plugs and use pipe / bottle cleaners down each one with degreaser. I also use welding rod with cloth on the end.
In my experience a hot chemical wash does not get the oil ways clean and the only way is to do it manually.
If you are spending time and money rebuilding an engine then its not worth the risk of some dirt in there.
I have had no problems pressure washing a block with cold water then blasting with an airline and then spraying WD40 on the machined surfaces.
Cleaning the bores after your bore and hone is also important. My test for a clean block is to pass a clean white cloth down the oil ways and bore, it should come out clean with no trace of brown. It normally takes me around 2 to 3 hours to clean a block AFTER a chemical hot wash.
I normally mask off the block, use a 2 pack chemical etch then engine paint. I do not paint the insides.
I also de burr all the sharp edges.
As mentioned alse where on the forum, buy David Vizards Tuning BL`s A Series engine even if you are doing a stock rebuild, its worth every pound.
just for your interest, the engines were painted inside. Well, my sidevalve anyway. That is red on the inside
Onne van der S. MMOCno 60520 Moderator
2dr 1971 White DAF 55 (with hopefully a 1600cc engine soon)
2dr 1973 Bergina (DAF 44)
2dr Estate 1975 DAF 46 in red
2dr saloon 1972 DAF 44 in Mimosa
If the pushrods have too much of a 'pip' the case hardened surface may suffer, I am not sure how thick the hardening is but if the rest of the surface is still ok then I would think stoning down to that level would be ok. You will have to make a judgement on that one.
