Re: What main caps to use w/out a girdle?
[Re: birdtracker]
#3035853
04/21/22 10:06 PM
04/21/22 10:06 PM
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Joined: Jan 2004
Posts: 8,356 fredericksburg,va
cudaman1969
master
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master
Joined: Jan 2004
Posts: 8,356
fredericksburg,va
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I have had 2 cast iron block motors. The 474 was a 400 block with the factory caps and an offset ground factory crank, It had 600 passes and I wore out the cylinders. I had a 440 cast block with aluminum caps that had a 4.375 stroker crank. It had a ton of passes. I put 300 on it and traded it to a guy who ran it to. My opinion since I have ran both is it doesn't matter as long as you have a straight line bore and good crank and the right bearing clearance. Birdtracker But it’s not as cool!
Last edited by cudaman1969; 04/21/22 10:07 PM.
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Re: What main caps to use w/out a girdle?
[Re: birdtracker]
#3035867
04/21/22 11:18 PM
04/21/22 11:18 PM
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Joined: Aug 2003
Posts: 43,315 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,315
Bend,OR USA
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I have had 2 cast iron block motors. The 474 was a 400 block with the factory caps and an offset ground factory crank, It had 600 passes and I wore out the cylinders. I had a 440 cast block with aluminum caps that had a 4.375 stroker crank. It had a ton of passes. I put 300 on it and traded it to a guy who ran it to. My opinion since I have ran both is it doesn't matter as long as you have a straight line bore and good crank and the right bearing clearance. Birdtracker I've built a bunch of BB Mopar stroker motors (pump gas street and strip and drag race only on race gas) with stock 400 and 440 block as well as few with after market race blocks, skip the girdles and use a set of after market main caps, ductile iron, aluminum and maybe even steel caps now that you can't buy the ductile iron main cap kit from Mopar anymore Make sure and use a good set of studs and have the block aligned hone to get the new caps to fit properly I've made over 820+ HP on race gas with a 440 block prepped(526C.I. with CNC ported 440-1 heads 440-3 single four cast aluminum intake manifold and a older Holley list #9375 1050 CFM Dominator carb on 112 octane race gas) that way years and years ago, it is still running with no issues according to the owner I sold it to If you look at the stock BB Mopars and Gen 2 hemi blocks they have a lot of stock cast in main bearing support hanging down to the oil pan rail, no girdle or 4 bolt main caps needed EDITED, use a good 400 block after having it sonic tested first for all out high HP(700+) and higher RPM, above 6000 RPM due to the stock 440 blocks and the other stock RB blocks cracking the main webbing above the main bearings up to the bottom of the cylinder walls, don't ask me how I know about this Buy a new race block is the best choice to start with if you can swing it
Last edited by Cab_Burge; 04/21/22 11:22 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: What main caps to use w/out a girdle?
[Re: GTXMEX]
#3035876
04/22/22 12:08 AM
04/22/22 12:08 AM
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Joined: Nov 2015
Posts: 884 Missouri
jwb123
super stock
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super stock
Joined: Nov 2015
Posts: 884
Missouri
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I had Herb McCandless tell me that a high HP stock block either needed aluminum rods or aluminum main caps to survive. On a stock block original main caps at the HP levels you are asking about, my experience is it will break number 2 main cap, not if but when. Never had an aluminum main cap fail. When I used a girdle I went with steel main caps, as with a girdle you are trying to make everything ridged as possible. I have used 440 source steel main caps with no problems. With steel main caps and a girdle I hod one engine barrel the cylinders, and it had block filler in it, the cylinders pushed so hard it cracked the block between the freeze plugs, about 500 passes on it. The next one cracked the webbing between the number 2 main and the cam journal, never blew up just found it on a freshen. Bought an after market block, best investment I ever made, take it apart after 300 runs looks like brand new. I know they are expensive but no way I would ever try and make 700HP with a stock block again, not worth the risk of blowing an engine and wrecking the car. Back when I was doing it nobody made an after market block.
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Re: What main caps to use w/out a girdle?
[Re: quickd100]
#3035894
04/22/22 06:33 AM
04/22/22 06:33 AM
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Joined: Jan 2003
Posts: 10,021 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,021
Frostbitefalls MN (Rocky&Bullw...
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There is one very IMPORTANT item nobody has mentioned. Keep the motor from DETONATION! Nothing will kill it faster!! And to add to that bit of esential info, here is what i would build. 400 block, aluminum main caps, studs, aluminum BME396 forging rods, and pistons with . 043 rings. Fill the block part way with Hardblock. Geting the bob weight very light will help a great deal. An expensive investment, but one that will take a lot of stress out of the short block is a center counter weighted crank. That evens out the loads on the main bearings, greatly reducing stress on the block. I would consider going hbeam rods to save $$ toward the expensive CCW crank. I have been running the same CCW Crower crank since 2005.
Last edited by gregsdart; 04/22/22 06:58 AM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: What main caps to use w/out a girdle?
[Re: GTXMEX]
#3035997
04/22/22 12:27 PM
04/22/22 12:27 PM
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Joined: Jan 2003
Posts: 75,098 A Banana Republic near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,098
A Banana Republic near you.
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Expect engine will have 620 - 700 HP. Milodon's new main cap offering shows long wait time. What else to go with? What block are you working with ?
running up my post count some more .
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Re: What main caps to use w/out a girdle?
[Re: JohnRR]
#3036021
04/22/22 01:06 PM
04/22/22 01:06 PM
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Joined: Jan 2003
Posts: 19,385 Las Vegas
Al_Alguire
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 19,385
Las Vegas
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Studs and aluminum caps, keep it out of detonation and let her rip.
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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