Title: Main bearing strengtheners, Main Cap Bridges ??? Post by: spinach on August 23, 2003, 12:06:46 AM Hi Guys....
1 more thing to ask while I'm killing some time at work, I've been reading some of the threads/posts about performance and I keep coming across these strengtheners and bridges. I've asked a mechanic mate of mine if he knew what they were and he came up blank. I saw a photo somewhere that had these bridges circled, but cant find the thing for the life of me. I've tried the search function trying a few different variations but I still cant find the photo. Could someone please explain to me in a bit of detail how I'd go about putting these onto my bottom end? Or if anyone has that photo could they please post it again for me? thanks in advance. spin. ps- once this grey motor im building is complete a friend has promised me some dyno time in exchange for a carton of corona's, im curious to see how many poines the old girl has under the bonnet. Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: Ed on August 23, 2003, 03:35:10 AM Hi Spin,
Strengthened main caps are usually redesigned to have more meat (hence stronger) and can be 1 bolt on either side (2 bolt main) or 2 bolts on either side (4 bolt main). Usually required if u have substantially more torque and ur std bottom threatens to throw itself away. Depending on what's available you may have to re-drill ur exisiting main cap threads (in your block) for larger diameter bolts. Or have your block machined to the correct height for bigger 4 bolt mains and all associated drilling etc. I've got photos of various V8 main caps to give u an idea if u like, but prob not much use for the grey. Some of the go-fast-grey-guys in here may know some relatively easy fixes for stronger main caps, or good donor parts required. I had a bit of engine machining done by a guy who loves his Early Holden stuff and had stroked greys using a Buick crank. After all this rambling, I re-read ur post and u didn't even mention which motor.. I'm presuming grey? OF course if you're sticking with the good old home grown Holden V8 there is plenty of gear to give those Chev guys a scare... and beat em too! :P 383 stroker in a FE is sounding nice..mmmm *snap* back to reality.. up to painting wasn't I? ::) hope this helps. Email me if u want the details for a good machine shop in Sydney who knows grey motors. PS he was making repro rocker arms too. Cheers Ed Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: spinach on August 23, 2003, 04:43:35 AM cheers ed, its a grey for now but.....dreams of a forced induction ford eating 5litre still play in my head.
can I grab the details of that machine shop please? I'd be willing to fork over for transport to find a place with ye olde holden experience. now a stroked grey, that would be classic spin. Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: Ed on August 23, 2003, 04:50:45 AM Hi Spin,
Dont see much harm in posting these details despite crap privacy laws. ( these are in the white pages anyway) Dominator Engines 9681 3462 Guildford NSW Speak to Terry. Cheers Ed Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: FE_225 on August 23, 2003, 08:56:21 AM Hi Spin
I've got a set for grey, I can measure them up for you if you want to knock up your own. They're not hard to make. You'll find a pic of them here.... http://photo.starblvd.net/~IhadaV8/1-2-3.jpg?i=1034820279 Cheers Tony Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: spinach on August 23, 2003, 11:56:51 AM Tony if you did that I would seriously fill out a nomination form to make you australian of the year. I really really want this grey motor to hum. if you could give me the rough measurements mate it would be much appreciated.
thanks spin. Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: normd on August 23, 2003, 02:18:16 PM Hey Guys
Another thing to watch is the big-ends on the rods when beefing up the motor, I have a "trophy" in my shed , pulled the bottom out of the big-end . Bolts were still in the rods but "PLENTY" of little bits & pieces in the sump and a "whackin'" great hole in the side of the block >:( >:( :o. Guess who needed a complete new long motor , (did the head in as well) the piston still has the imprint of the head on it . :-/ Norm Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: FE_225 on August 24, 2003, 10:09:14 AM Hey Spin
Australian of the year? your too kind ;D Here's those measurements and another pic Main bar is 4 1/4" long, 1" wide and 3/4" thick, with a hole dead centre for the grub screws. The spacers are 22/32" in diameter and 13/32" high The 2 grub screws are 3/8" by 1/2" The main cap bolts need to be 1 3/16" longer than standard. When you go to fit them, remove the original cap bolts and fit the bridge as per the other pic, using the longer bolts. Torque down to standard specs. You'll then notice a small gap between the bottom of the bridge and the top of the main cap, that's normal. Drop in the first grub screw and screw it thru until it just touches the top of the main cap, then nip it up a little so it fits snuggly against the main cap. Drop in the second grub screw and tighten it up nice and tight. This one just locks the first one in place so it can't come loose. Simply, hey! (http://photo.starblvd.net/~IhadaV8/1-3-1.jpg) Cheers Tony Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: spinach on August 26, 2003, 06:38:32 AM tony, cheers again mate. ive passed on a good word to the queen about ya and chances are you'll be knighted before the years out.
spin. Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: Effie C on August 26, 2003, 07:17:30 AM Or at least crowned by your missus, Tony ;)
John M Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: spinach on August 27, 2003, 09:34:48 PM if ya dont mind tony, i've just got a couple more q's. I gave the photo and the measurements to a fitter and turner friend of mine, and he told me to ask a few things. I need the standard bolt length, I've had a look in my old holden book, but I cant seem to find a specified length. Also the diamater of the stock used to make the bolts... (see photo)
(http://photo.starblvd.net/~spinach/1-1-1.jpg?i=1064608502) Are the bolts made of 1 piece of stock? the diamater of the holes drilled in the flat bar for the bolts? 1 more i promise, just the distance from the edge to drill the holes for the bolts. (http://photo.starblvd.net/~spinach/1-1-2.jpg?i=1064610858) sorry for all the questions, really appreciate all your help. spin. Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: 4hammers on August 27, 2003, 10:03:07 PM Hi Spin
If you like, I have a NOS set that I can send you up so you can copy. As long as I can get them back as soon as you have finished with them. Let me know, Regards, Rob J Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: spinach on August 27, 2003, 10:43:59 PM REALLY!!!?? Mate if you could send 1 up to copy I would be in your debt, I would have it back to you asap. Just long enough to get every possible measuerment off it. I could deposit some cash in your account as insurance if you like, it's hard to prove your honest over the internet!
spin. Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: 4hammers on August 28, 2003, 01:17:04 AM Hi Spin.
That's cool, no debt. I will get you to send me your address via email if you can & I will get one off to you. Don't worry about the cash, if you use this forum, you must be OK. One tip that I will give you guys, is that when tightening the grub screws down, don't go too hard. We have a fella in the club here who just did it & the mechanic has torqued them down, with the grub screws sticking out too far. This has caused the the caps to warp & looks like it has scored his brand new balanced crank. :-/ my email is: r2t2@bigpond.com.au Regards, Rob J Title: Re: Main bearing strengtheners, Main Cap Bridges ? Post by: spinach on August 28, 2003, 02:39:54 AM cheers rob, emailed you my details. thanks again to all for the help, thanks for the photos and measurements tony, just going by those alone a mate of mine has already knocked up 6 of the pieces of bar with the centre hole drilled and enough grub screws to fit 10 of 'em.
spin aka luke. Title: Re: Main bearing strengtheners, Main Cap Bridges ??? Post by: Old_Mt_Isa_Boy on May 02, 2010, 08:55:17 AM Hi Spinach how did you go making the strengtheners and bridges? Have you got any photo's
Regards Wayne |