girdle with integrated bearing caps

ppyvabw · Post by **ppyvabw** » Mon Jan 28, 2008 7:29 pm

Just won a new engine on ebay. The first thing i'd like to do to it is, (if fiscally possible) build a girdle.

I probably can't afford to have an integrated one machined. These are probably stupid questions, but I could probably get a mate to make me some bearing caps, and a seperate girdle to fit underneath pretty cheaply.

Would it be feasible, in principle atleast, to weld up the girdle from the individual parts, possible machining afterwards if it warps, and then having the block line honed?

What metal would I use, steel or alloy. Presumably, these things also bolt onto the bottom edge of the block, where the sump goes. Would I bolt this on seperately, with some small bolts countersunk into the girdle, or just not bother, and put the sump bolts straight through? Would the girdle, require a gasket inbetween it and the block?

kiwicar · Post by **kiwicar** » Mon Jan 28, 2008 7:36 pm

what's the engine? rover 302 ford SBC, lexus?
Mike

ppyvabw · Post by **ppyvabw** » Mon Jan 28, 2008 7:39 pm

Oops, sorry, that's kind of a vital piece of info. Am too excited about the prospect of building another engine

3.9L rover

kiwicar · Post by **kiwicar** » Mon Jan 28, 2008 8:12 pm

The rover is a y block so it extends beyond the bearing caps, the simplest thing to do would be to make up long caps that come flush with the bottom of the block (in ally) and then make up a plate to go across the whole of the bottom of the engine (someone posted photos of one they made up on here) and use long studs to bolt the caps through the plate. You will have to get the caps machined perfectly flat with the lower surface of the block though which will be tricky. If you extend the plate an inch each side past the sides of the block and put more and/ or bigger diamiter studs in place of the sump fixing bolts it will make the whole bottom end very stiff. I wouldn't try and weld the caps on, The heat will warp the whole thing.
Mike

ppyvabw · Post by **ppyvabw** » Mon Jan 28, 2008 8:21 pm

So will the bottom plate need a gasket, presumably yes, which means the caps have to ever so slightly proud of the bottom of the block, yes, or just one whole gasket on the whole thing?

So what about the sump, that will need new fixing holes drilling in the plate yeah? They will be in the same place as the studs holding the plate on. Are you suggesting moding the sump, to fit on these 1inch extensions past the edges of the block?

From where would I get longer studs. Have them made?

I will have a good look for these photos you mention, are they in the engine forum?

ppyvabw · Post by **ppyvabw** » Mon Jan 28, 2008 8:24 pm

found em, Christ alive

kiwicar · Post by **kiwicar** » Mon Jan 28, 2008 11:10 pm

Hi
the bottom plate will have no gasket, it will have to be flat like the bottom of the block, put a gasket in there then it will all flex, properly flat and lapped to a good surface and all you will need will be a very thin film of silicon (probably not even that). You will need longer studs for the sump (with a gasket here, it's only bent tin) but between each sump fixing hole you will probably want one maybe two bolts holding the plate to the block, tapped into the block and counterbored into the plate.
Use the standard sump and sump fixing holes as described above, the extension is to give extra resistance to twisting think of it making the sides of the block into the half an I beam.
Studs will be from ARP or similar, they make studs in many lengths, they sell them as kits for engines to make them easy to sell.
You will probably have to make cutouts on the outside flange bit for starter and oil filter but armed with the photos and a block you will be away.
Best regards
Mike

ppyvabw · Post by **ppyvabw** » Mon Jan 28, 2008 11:24 pm

outstanding, that makes sense, thanks mate I can probably start the plate bit myself just for the price of the ally which is something I can be doing whilst I have not a lot of dosh.

Been a while since i built my first rover engine. There's gonna be some drain holes at the front isn't there, looking at those pics, an extension to the oil pick up thingy and if I want a good surface to surface contact, maybe having the bottom of the block skimmed slightly to clean it up, yes no?

Wotland · Post by **Wotland** » Tue Jan 29, 2008 11:37 am

Hello,
I made one girdle plate last year.
http://www.v-8.org.uk/forum/viewtopic.php?t=2182

chodjinn · Post by **chodjinn** » Tue Jan 29, 2008 12:30 pm

That's an absolute beast Dimitri! I had forgotten all about that.

Tell me, how did you address the issues of the mains caps/flushness with the bottom of the block as mentioned above?

I was thinking you could just extend the girdle slightly in the required places @ the mains cap areas - this would also aid in stiffness.

Does the offer still stand to make more of these? I'm more interested since I got myself of a 4.6 engine!

cheers

olly

kiwicar · Post by **kiwicar** » Tue Jan 29, 2008 3:57 pm

he is cross bolted, here all he really needs to do is shim the existing caps to make them flush with the bottom of the plate, the sides of the caps are held in place by the block directly so the plate and the studs are not all that is holding the bearings in line. It will still seriously stiffen things though! Making the plate more closley fit around the crank and rods and extending it out to form a flange (especially along those loverly big webs by the starter) around the bottom of the block would make it really ridged.
Mike

chodjinn · Post by **chodjinn** » Tue Jan 29, 2008 5:10 pm

Sorry I'm a bit confused here - shim the mains caps? How?!

HairbearTE · Post by **HairbearTE** » Tue Jan 29, 2008 9:01 pm

You need to measure the distance between the bolt surface of the caps and the newly made girdle and shimm accordingly. In an ideal world the girdle will be heat-treated then milled flat on both sides too.. Mike talked me through this procedure and wisely pointed out that gasket crush must be considered when measuring for the shims, something that could be overlooked.

ppyvabw · Post by **ppyvabw** » Tue Jan 29, 2008 9:21 pm

another very silly question....

I am going to drill and tap new holes in the bottom of the block to take bolts, yes? And studs for the sump bolts. The counter sink holes must be big enough to get a socket down to do them up. This will mean the sump gasket won't seal properly. Hope that makes sense.

kiwicar · Post by **kiwicar** » Tue Jan 29, 2008 9:56 pm

shouldn't be a problem sealing it, you won't be using big bolts between the existing sump fixing holes, M5 may be M6, use an allen cap bolt in a close fit counter bore in the plate then when you put the sump on over it the sump gasket will cover them. If this doesn't do the job then cap the counter bores with ally bar plugs and a dash of silicon sealer and the sump gasket will do the rest.
Mike
PS I would still make new caps and machine them flush with the bottom of the block, shimming can be done and made to work but not as stable as an exact machined fit.