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Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1877765 07/25/15 11:18 AM 07/25/15 11:18 AM
Joined: Feb 2005 Posts: 4,321 Prospect, PA BSB67 master
BSB67 master Joined: Feb 2005 Posts: 4,321 Prospect, PA	Is this what you are referring too? 70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas 9.87 @ 136. If so, seems like it might be a bit more than 600 hp? Last edited by BSB67; 07/25/15 11:19 AM.

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1877767 07/25/15 11:19 AM 07/25/15 11:19 AM
Joined: Mar 2012 Posts: 220 J Jerry Kathe enthusiast
Jerry Kathe enthusiast J Joined: Mar 2012 Posts: 220	Sorry to see that. I think you should just stop messing with these money pits and sell me the roller - lol. In all seriousness though - 1. Do you run stock firing order? 2. If so, can you post up a few photo's of the mating surfaces, both the block and cap of the #4 main. Thanks.

Re: Cracked Mains W/ Aluminum Caps [Re: BSB67] #1877787 07/25/15 12:08 PM 07/25/15 12:08 PM
Joined: Jul 2010 Posts: 1,491 Oologah, Oklahoma Big Squeeze pro stock
Big Squeeze pro stock Joined: Jul 2010 Posts: 1,491 Oologah, Oklahoma	Originally Posted By BSB67 Is this what you are referring too? 70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas 9.87 @ 136. If so, seems like it might be a bit more than 600 hp? The car must weigh 3,000 race ready. If you can't handle the truth, you're living a lie.......

Re: Cracked Mains W/ Aluminum Caps [Re: sr4440] #1877794 07/25/15 12:19 PM 07/25/15 12:19 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Originally Posted By sr4440 I would be interested in knowing what the max timing was on the blocks that cracked. the reason i ask is i run 843HP (corrected) on my 400 (aluminum caps and griddle) and we put a blower on one and made 1240 hp but kept cracking upper cylinder walls (that block was cross bolted and had a griddle on it also) I run 31 degrees of timing. Joe They are cracking for one reason... detonation... to SR4440 31* is a lot on a blower... but other factors also come into play... fuel, wall thickness.. and cam.. and more... to the OP... did you put the alum caps on at day 1 of that build and what was the timing, fuel and cranking pressure

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1877815 07/25/15 12:57 PM 07/25/15 12:57 PM
Joined: Jan 2003 Posts: 31,078 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 31,078 Oregon	If you have more 440 blocks and all of your parts are for RB engines then I'd build another 440. You might just think hard about ways to reduce detonation and reduce problems for the bottom end. Aluminum rods might help, double check the balance job on the rotating assembly, careful look at the tops of the pistons and the combustion chambers, double check your AF numbers, etc. You might have a distribution problem and maybe one cylinder is running lean and you don't know it. 6bbl systems are fairly famous for having problems like that.

Re: Cracked Mains W/ Aluminum Caps [Re: BSB67] #1877819 07/25/15 01:02 PM 07/25/15 01:02 PM
Joined: Jan 2003 Posts: 3,842 N.E. Ohio 6bblFLASH OP master
6bblFLASH OP master Joined: Jan 2003 Posts: 3,842 N.E. Ohio	Originally Posted By BSB67 Is this what you are referring too? 70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas 9.87 @ 136. If so, seems like it might be a bit more than 600 hp? Yes 70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas 9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ! 2013 StickShift Challenge Winner@ Mopar Nationals!

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1877821 07/25/15 01:09 PM 07/25/15 01:09 PM
Joined: Jan 2003 Posts: 3,842 N.E. Ohio 6bblFLASH OP master
6bblFLASH OP master Joined: Jan 2003 Posts: 3,842 N.E. Ohio	Detonation and general abuse are the most likely culprits. I have proof that #4 cyl has seen detonation over the years. Flow in the intake is pretty bad on#4. I`m wanting a bigger cube and less compression like 10.5 or so. Any opinion on 383 blocks? 70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas 9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ! 2013 StickShift Challenge Winner@ Mopar Nationals!

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1877838 07/25/15 01:37 PM 07/25/15 01:37 PM
Joined: Jan 2003 Posts: 31,078 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 31,078 Oregon	440 blocks are usually stronger than 383 blocks but 400 blocks might be better than either. Hard to say really with any certainty. This stuff is all 40+ years old. More cubes and less compression might be the ticket. A 4.25 crank in a 440 builds a 505. With 6.80 or 7.10 rods you have a super nice bottom end and plenty of room for a dished piston to get you to 10.5 compression. You can change the gearing and run lower engine speed while still having the same basic power and same ET.

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1877842 07/25/15 01:52 PM 07/25/15 01:52 PM
Joined: Jan 2003 Posts: 17,926 Akron, Ohio ProSport I Live Here
ProSport I Live Here Joined: Jan 2003 Posts: 17,926 Akron, Ohio	Many years ago when I was just learning, someone told me that if I want to make it live I needed to go with a 400 block with aluminum caps and no girdle. So I tried it, and made 9 second passes for about 7 years, then ran that same type of combo in another 9 second car for 5 years. Everyone has their own opinions, I'm just telling you what worked for me. I don't know why, but all my friends that have blown up their motors over the years, have all been RB blocks. But alot of guys here on Moparts run them every weekend. 1970 Challenger, all aluminum 528 Hemi, HDK suspension, Tremec 5 speed manual

Re: Cracked Mains W/ Aluminum Caps [Re: MR_P_BODY] #1877868 07/25/15 02:32 PM 07/25/15 02:32 PM
Joined: Feb 2008 Posts: 715 Central TEXAS!!!! sr4440 super stock
sr4440 super stock Joined: Feb 2008 Posts: 715 Central TEXAS!!!!	Originally Posted By MR_P_BODY Originally Posted By sr4440 I would be interested in knowing what the max timing was on the blocks that cracked. the reason i ask is i run 843HP (corrected) on my 400 (aluminum caps and griddle) and we put a blower on one and made 1240 hp but kept cracking upper cylinder walls (that block was cross bolted and had a griddle on it also) I run 31 degrees of timing. Joe They are cracking for one reason... detonation... to SR4440 31* is a lot on a blower... but other factors also come into play... fuel, wall thickness.. and cam.. and more... to the OP... did you put the alum caps on at day 1 of that build and what was the timing, fuel and cranking pressure I am sorry, 31 was on my NA junk. I think we were around 21-22 with 10 PSI of boost on the blower. Joe Without Data, you’re just another guy with an opinion.

Re: Cracked Mains W/ Aluminum Caps [Re: AndyF] #1877887 07/25/15 03:26 PM 07/25/15 03:26 PM
Joined: Jan 2005 Posts: 176 Sterling Heights, MI John_T_Brown member
John_T_Brown member Joined: Jan 2005 Posts: 176 Sterling Heights, MI	Originally Posted By AndyF If you have more 440 blocks and all of your parts are for RB engines then I'd build another 440. You might just think hard about ways to reduce detonation and reduce problems for the bottom end. Aluminum rods might help, double check the balance job on the rotating assembly, careful look at the tops of the pistons and the combustion chambers, double check your AF numbers, etc. You might have a distribution problem and maybe one cylinder is running lean and you don't know it. 6bbl systems are fairly famous for having problems like that. +1 The major problem with stock block main problems are with balance, anything that disrupts that (bob weight, fuel mixture, timing, etc.) will cause the bottom end to do ugly things. Here is an excellent article on the subject Engine Balance Last edited by John_T_Brown; 07/25/15 03:34 PM. If it ain't broke fix it anyway!

Re: Cracked Mains W/ Aluminum Caps [Re: John_T_Brown] #1877895 07/25/15 03:43 PM 07/25/15 03:43 PM
Joined: Aug 2003 Posts: 43,308 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,308 Bend,OR USA	All three RB blocks(1 426 M.W., two 440) I've seen up until now that cracked the main webs where under #1 and #3 cylinders up towards the cylinder walls I've seen other GM blocks crack the mains like the one pictured here, me thanks that is mainly weakness in the castings and design Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: Cracked Mains W/ Aluminum Caps [Re: sr4440] #1877950 07/25/15 05:54 PM 07/25/15 05:54 PM
Joined: Aug 2006 Posts: 2,141 junction city oregon V viperblue72 top fuel
viperblue72 top fuel V Joined: Aug 2006 Posts: 2,141 junction city oregon	Originally Posted By sr4440 Originally Posted By MR_P_BODY Originally Posted By sr4440 I would be interested in knowing what the max timing was on the blocks that cracked. the reason i ask is i run 843HP (corrected) on my 400 (aluminum caps and griddle) and we put a blower on one and made 1240 hp but kept cracking upper cylinder walls (that block was cross bolted and had a griddle on it also) I run 31 degrees of timing. Joe They are cracking for one reason... detonation... to SR4440 31* is a lot on a blower... but other factors also come into play... fuel, wall thickness.. and cam.. and more... to the OP... did you put the alum caps on at day 1 of that build and what was the timing, fuel and cranking pressure I am sorry, 31 was on my NA junk. I think we were around 21-22 with 10 PSI of boost on the blower. Joe A 400 block is a different ball game. Much more rigid block.

Re: Cracked Mains W/ Aluminum Caps [Re: sr4440] #1877970 07/25/15 06:29 PM 07/25/15 06:29 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Originally Posted By sr4440 Originally Posted By MR_P_BODY Originally Posted By sr4440 I would be interested in knowing what the max timing was on the blocks that cracked. the reason i ask is i run 843HP (corrected) on my 400 (aluminum caps and griddle) and we put a blower on one and made 1240 hp but kept cracking upper cylinder walls (that block was cross bolted and had a griddle on it also) I run 31 degrees of timing. Joe They are cracking for one reason... detonation... to SR4440 31* is a lot on a blower... but other factors also come into play... fuel, wall thickness.. and cam.. and more... to the OP... did you put the alum caps on at day 1 of that build and what was the timing, fuel and cranking pressure I am sorry, 31 was on my NA junk. I think we were around 21-22 with 10 PSI of boost on the blower. Joe Years ago I ran a 383 block but with a destroked engine that turned some high rpm...everything was light and it was a tunnel ram.. I measured EGT on all cyls just to see if the flow balance was decent... that engine lasted till I sold the car and it was still running.. of course this was before the 400 blocks

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1880087 07/28/15 03:16 PM 07/28/15 03:16 PM
Joined: Jan 2003 Posts: 75,095 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,095 A Banana Republic near you.	Originally Posted By 6bblFLASH I can clearly see I got away with a potential disaster. Block was not "fresh" and really have no record of its history. So now the debate in my head,,,,,lots of empty space for a debate in there.... Low deck or another RB. I was looking at some of those 383 strokers. I DO have 3 virgin 383 blocks and 3 virgin 440`s Don`t want more power,just a little more confidence in my engine.... Opinions I would say build a low deck , but get a 400 ... this is coming from the guy that is building 383's, but if you go with a 440 use a late block .

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1880117 07/28/15 04:02 PM 07/28/15 04:02 PM
Joined: Nov 2004 Posts: 6,890 North Alabama M Monte_Smith master
Monte_Smith master M Joined: Nov 2004 Posts: 6,890 North Alabama	My advice would be to buy a good block........which would likely eliminate the chance of you being here in a 150 more passes with the same type pictures, asking for opinions on what to do. You guys can talk about detonation, balance and all this other stuff. Doesn't change the fact that the blocks are weak there and any 30 year old block to be used as a race block is a serious crap shoot. Even if it is out of your one owner, 67 model grandma car that only has a few thousand miles and never driven over 30mph............Still don't mean a damn thing..........it's a stock block.

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1880122 07/28/15 04:09 PM 07/28/15 04:09 PM
Joined: Jan 2003 Posts: 19,384 Las Vegas Al_Alguire I Live Here
Al_Alguire I Live Here Joined: Jan 2003 Posts: 19,384 Las Vegas	Agree the only true solution is an aftermarket block. That is another can of worms for sure. Best bandaid IMO is aluminum caps, aluminum rods, and keep the bobweight as low as possible. Low deck in generally considered stronger than a tall deck deal and will be a lighter bobweight. Detonation will certainly speed up the demise of either one for sure. So your choice. Spend the money on a stock block and cross your fingers or pony up for an aluminum block as that is all that's out there except for those of us hoarding steel ones "I am not ashamed to confess I am ignorant of what I do not know." "It's never wrong to do the right thing"

Re: Cracked Mains W/ Aluminum Caps [Re: Monte_Smith] #1880124 07/28/15 04:11 PM 07/28/15 04:11 PM
Joined: Aug 2003 Posts: 43,308 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,308 Bend,OR USA	Originally Posted By Monte_Smith My advice would be to buy a good block........which would likely eliminate the chance of you being here in a 150 more passes with the same type pictures, asking for opinions on what to do. You guys can talk about detonation, balance and all this other stuff. Doesn't change the fact that the blocks are weak there and any 30 year old block to be used as a race block is a serious crap shoot. Even if it is out of your one owner, 67 model grandma car that only has a few thousand miles and never driven over 30mph............Still don't mean a damn thing..........it's a stock block. I talked to Ken Black last week about one of his street wedge blocks, costs, time and options. I'll use the 400 block supply up that I have for most not all out builds and use the Koleno and World blocks I have for the serious builds Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: Cracked Mains W/ Aluminum Caps [Re: Cab_Burge] #1880153 07/28/15 04:57 PM 07/28/15 04:57 PM
Joined: Jan 2003 Posts: 3,842 N.E. Ohio 6bblFLASH OP master
6bblFLASH OP master Joined: Jan 2003 Posts: 3,842 N.E. Ohio	Lots of ideas to ponder,,,,, thanks for the advise. Simple math is an aftermarket block is out of the question. Last 5 years I`ve probably only made 100 passes. Only go zero to 5 times a year anymore. In all likelyhood it will be summer 2016 before it makes another pass. I have the stuff already to build the same+.030 block,crank etc... Want something better......... Like the idea of a 400 stroker more cubes less compression. I`ll get some pictures of the parting line 70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas 9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ! 2013 StickShift Challenge Winner@ Mopar Nationals!

Re: Cracked Mains W/ Aluminum Caps [Re: 6bblFLASH] #1880167 07/28/15 05:13 PM 07/28/15 05:13 PM
Joined: Sep 2014 Posts: 4,457 Washington M madscientist master
madscientist master M Joined: Sep 2014 Posts: 4,457 Washington	Some how we have gotten to the point where guys making 600 real HP (as the OP says he is) don't think they need an aftermarket block. Not only is reliabilty down using P car blocks so is your HP. Your tune up window is significantly reduced, so a minor tuning error will cost you big time. If you can't afford/want an aftermarket block, think about a reduction in HP and RPM. What you are using was never designed to have done to it what you are doing. All the tricks in the world won't help that. Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston

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