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Re: which rod for a bracket motor [Re: rebel] #2190193
11/05/16 06:44 PM
11/05/16 06:44 PM
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Posts: 20,116
PA.
pittsburghracer Offline
"Little"John
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"Little"John

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PA.
Honestly there aren't a lot of 900 horesepower 8000 rpm engines on this site. Then subtract the dyno queens, show cars, and cruisers or many can give you good info. Asking for total passes instead of years is the only way you will get good feedback. Forty years plus of racing for me an I hope to have my first 900 horsepower engine next year


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: which rod for a bracket motor [Re: rebel] #2190194
11/05/16 06:49 PM
11/05/16 06:49 PM
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Shelby Twp. Mi
HardcoreB Offline
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There was a good exchange of this same topic somewhere over on the Bullet. But for steel, at that power lever/CID and well above, the Ultra was pretty highly regarded. RMRE uses Manley in there builds which exceed your limits. If you are on the margin of using a 'cheap' crank you may want to consider aluminum however. The comparison post only gave you a reference of cross-sections. The entire process of manufacturing gives one strength over another which goes beyond mere cross-section and weight comparisons. Processes that minimize inclusions etc.

Re: which rod for a bracket motor [Re: rebel] #2190300
11/05/16 09:41 PM
11/05/16 09:41 PM
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Portage,michigan
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B3422W5 Offline
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I brought up the molnar Rod itself breaking because it did. The guy who had that failure is a veteran racer most around these parts know well.

Regards compstar, I ran them for years in a motor that saw 7500 every pass, current owner still has them in the motor.
I ran them on the advice of Chuck at Best Machine, who built that motor. He had high praise for them in that price segment.
Just relaying my experiences. Those wise asses who cast stones always do.

Last edited by B3422W5; 11/05/16 09:41 PM.

69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8

Re: which rod for a bracket motor [Re: B3422W5] #2190324
11/05/16 10:00 PM
11/05/16 10:00 PM
Joined: Dec 2006
Posts: 4,647
aotearoa
rebel Offline OP
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Originally Posted By B3422W5
I brought up the molnar Rod itself breaking because it did. The guy who had that failure is a veteran racer most around these parts know well.

Regards compstar, I ran them for years in a motor that saw 7500 every pass, current owner still has them in the motor.
I ran them on the advice of Chuck at Best Machine, who built that motor. He had high praise for them in that price segment.
Just relaying my experiences. Those wise asses who cast stones always do.


this is the kind of stuff i want to hear about. Just as someone mentioned 440 Source, i've physicly seen the aftermath of their rods breaking at only 7000 rpm & high 600 HP & it was rod failure, nothing else. I am seriously thinking Compstar but just thought i'd test the waters & see what others might suggest. Thank you for your input.

Re: which rod for a bracket motor [Re: rebel] #2190335
11/05/16 10:12 PM
11/05/16 10:12 PM
Joined: Jan 2003
Posts: 11,701
Portage,michigan
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B3422W5 Offline
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Originally Posted By rebel
Originally Posted By B3422W5
I brought up the molnar Rod itself breaking because it did. The guy who had that failure is a veteran racer most around these parts know well.

Regards compstar, I ran them for years in a motor that saw 7500 every pass, current owner still has them in the motor.
I ran them on the advice of Chuck at Best Machine, who built that motor. He had high praise for them in that price segment.
Just relaying my experiences. Those wise asses who cast stones always do.


this is the kind of stuff i want to hear about. Just as someone mentioned 440 Source, i've physicly seen the aftermath of their rods breaking at only 7000 rpm & high 600 HP & it was rod failure, nothing else. I am seriously thinking Compstar but just thought i'd test the waters & see what others might suggest. Thank you for your input.


Give Best Machine a call and see what those guys recommend. They have never steered me wrong, and always been top shelf in both knowledge and skill.


69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, 10.40 @127 1/4
1.41 best 60 foot
6.60 at 103.90 1/8

Re: which rod for a bracket motor [Re: rebel] #2190432
11/06/16 12:20 AM
11/06/16 12:20 AM
Joined: Mar 2006
Posts: 9,791
MI, usa
dvw Offline
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Originally Posted By rebel
your possibly right Pittsburgh, but i thought 900 HP & 8k rpm limit might have reduced the possible options for good answers. i guess i need to be more specific even with that info.
so looking for...
6.535 length STEEL H beam rods
900HP power output
8000 rpm limit
565grm Custom Ross Pistons
No spray
4.250 stroke
am i missing anything?

Power really doesn't factor into it. That being said mine has a 7500 rpm limit, 4.5 stroke, 157 gram pin, 630 gram piston. If it's a bracket motor the aluminum rods might be out do to number of passes. I ran my BME 300 passes w/o issue before I swapped to Molnar (7.100/2.200/.990). Motor's never been on the dyno but will run 9.0-9.1@146-148 depending on weather at 3350lbs.
Doug

Re: which rod for a bracket motor [Re: rebel] #2190582
11/06/16 11:19 AM
11/06/16 11:19 AM
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Apollo, PA.
B1MAXX Offline
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Originally Posted By rebel
your possibly right Pittsburgh, but i thought 900 HP & 8k rpm limit might have reduced the possible options for good answers. i guess i need to be more specific even with that info.
so looking for...
6.535 length STEEL H beam rods
900HP power output
8000 rpm limit
565grm Custom Ross Pistons
No spray
4.250 stroke
am i missing anything?


I wouldn't run an h beam in this app. steel billet I beam would be my choice... Crower. That being said the few 900
+hp 8200+rpm engines I have personally touched had BME aluminum rods.

My twocents

Re: which rod for a bracket motor [Re: rebel] #2190609
11/06/16 11:55 AM
11/06/16 11:55 AM
Joined: Oct 2004
Posts: 3,097
back in Georgia
dthemi Offline
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Another thing that is more troublesome than cheap rods, are cheap cranks. I've seen many eagle crank and rod combos hang in there at and above 900 when properly machined. Meaning get the crank turned .01, redo the housing bore, and pin fit on the rod, and go for .0035+ for oil so it can deal with the flex. Much above that, and it looks to me like crank flex is what starts the downfall.

Re: which rod for a bracket motor [Re: rebel] #2190829
11/06/16 06:06 PM
11/06/16 06:06 PM
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Posts: 4,647
aotearoa
rebel Offline OP
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My crank seems to be strong enough to handle the duties but after checking a friends engine that was running less power than I run, I thought it would be a good move to upgrade before we experience the same failings as him. These rods have done 5 seasons n the hardware was changed at last rebuild. The hardware was fine but the rod failed badly

20161106_162423.jpg
Re: which rod for a bracket motor [Re: B1MAXX] #2190834
11/06/16 06:18 PM
11/06/16 06:18 PM
Joined: Mar 2009
Posts: 1,169
Virginia Beach, VA
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Old School Offline
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Originally Posted By B1MAXX
Originally Posted By rebel
your possibly right Pittsburgh, but i thought 900 HP & 8k rpm limit might have reduced the possible options for good answers. i guess i need to be more specific even with that info.
so looking for...
6.535 length STEEL H beam rods
900HP power output
8000 rpm limit
565grm Custom Ross Pistons
No spray
4.250 stroke
am i missing anything?


I wouldn't run an h beam in this app. steel billet I beam would be my choice... Crower. That being said the few 900
+hp 8200+rpm engines I have personally touched had BME aluminum rods.

My twocents
definitely this iagree I run Oliver I beam in all my motors. I would not use an h-beam rod in anything over 800 horsepower.. twocents

Last edited by Old School; 11/06/16 06:25 PM.

68 cuda formula S 588" bb 5sp
70 CUDA CONVERT 500" 5SP (SUBLIME)
70 CUDA CONVERT 500" 5SP (PLUMCRAZY):TOO MUCH HORSEPOWER, IS ALMOST ENOUGH!
Re: which rod for a bracket motor [Re: rebel] #2190854
11/06/16 07:00 PM
11/06/16 07:00 PM
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DFW
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mr_340 Offline
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My $.02 is I haven't been able to get any rod through my machinist's inspection. I bought some Manley Hemi I-beam rods off a SS Hemi racer. They were new in the box. The rod bolts were galled on the threads and under the bolt heads and cap. I paid $1300 for the rods and then another $1000 to get them fixed - new rod bolts, ring dowels, remachine the big ends and touch up the rod bolt seating areas, etc.

I've taken a set of 440 K1 rods and some Manley 440 I-beams to him. The Manleys checked out dimensionally, but the rods were in the mid-20s on the HRC scale, so basically in the annealed or normalized condition for 4340. The K1s were in the mid-30s HRC, but had some ovality in the pin and big end bores.

My machinist likes the Crowers and Carrillos and the CARR bolts. I'm thinking that is the way to go on an all out race engine. Why spend money ($600or so) on new rods, and then have to spend more fixing them? CARR bolts are about $50 each, so that's $800 for rod bolts alone. For the money I got in those Hemi rods, I would have been better off buying Carrillos with better bolts.


Floyd Lippencott IV
Re: which rod for a bracket motor [Re: rebel] #2190856
11/06/16 07:05 PM
11/06/16 07:05 PM
Joined: Oct 2004
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back in Georgia
dthemi Offline
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Originally Posted By rebel
My crank seems to be strong enough to handle the duties but after checking a friends engine that was running less power than I run, I thought it would be a good move to upgrade before we experience the same failings as him. These rods have done 5 seasons n the hardware was changed at last rebuild. The hardware was fine but the rod failed badly



Hard to tell from the picture, but it looks like it grabbed the bearing first, with the heat discoloration the picture shows. Were you able to find the bearings from that rod?

Re: which rod for a bracket motor [Re: rebel] #2190878
11/06/16 07:40 PM
11/06/16 07:40 PM
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aotearoa
rebel Offline OP
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The bearings were almost perfect n the rod journal was mint apart from a gouge where the rod bounced off it prior to snapping. At the break we found signs of stress cracking. This is a rod failure nothing else. OIL pressure on this motor had been excellent the week before as I was involved in prepping this motor for racing.

Re: which rod for a bracket motor [Re: rebel] #2190897
11/06/16 08:12 PM
11/06/16 08:12 PM
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MI, usa
dvw Offline
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A lot of opinions here. Some from experience on a personal level (Me) some from someone who has done many, many engine builds (DT Hemi), others just quoting what they might have heard. I read a lot. I talk to many people I feel have a good handle on the subject. From what I've gathered gram for gram a H beam will be stronger if the same material is used. The material can be placed in the higher stressed areas with out adding unneeded mass. I suggest talking to Tom Molnar personally. He designed rods at Oliver for many years. My bet is he knows more about rods than most. I agree with DTHemi. Most rod failures have either grabbed a bearing or broke a bolt. I also run extra bearing clearance to combat flex. So far zero rod/bearing failures with my builds.
Doug

Re: which rod for a bracket motor [Re: dvw] #2190900
11/06/16 08:16 PM
11/06/16 08:16 PM
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Originally Posted By dvw
A lot of opinions here. Some from experience on a personal level (Me) some from someone who has done many, many engine builds (DT Hemi), others just quoting what they might have heard. I read a lot. I talk to many people I feel have a good handle on the subject. From what I've gathered gram for gram a H beam will be stronger if the same material is used. The material can be placed in the higher stressed areas with out adding unneeded mass. I suggest talking to Tom Molnar personally. He designed rods at Oliver for many years. My bet is he knows more about rods than most. I agree with DTHemi. Most rod failures have either grabbed a bearing or broke a bolt. I also run extra bearing clearance to combat flex. So far zero rod/bearing failures with my builds.
Doug


Doug how many runs on the molnar rods so far?

Re: which rod for a bracket motor [Re: rebel] #2190912
11/06/16 08:44 PM
11/06/16 08:44 PM
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MI, usa
dvw Offline
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Right around 100 runs. This was my first year with them. I spent a fair amount of time researching for rods for my motor. Although the BME's worked excellent I felt 300 passes was a good number for replacement. I had absolutely no issues with them. Unfortunately my budget is hard pressed to purchase a $1200 set of rods every 300 runs. I have a Mega-Block and do not want to hurt it. I felt the Molnar's were a good compromise, time will tell. Also anyone interested in Aluminum rods to talk to Bill Miller. Both Bill and Tom spent time teaching me about the benifits of their style rods. Both good guys in my book.
Doug

Re: which rod for a bracket motor [Re: dvw] #2190922
11/06/16 09:03 PM
11/06/16 09:03 PM
Joined: Feb 2005
Posts: 20,116
PA.
pittsburghracer Offline
"Little"John
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"Little"John

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PA.
My first build with aluminum rods going in my 1000 plus horsepower build for next year

IMG_1170.JPG

1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: which rod for a bracket motor [Re: rebel] #2191000
11/06/16 10:30 PM
11/06/16 10:30 PM
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Posts: 8,192
fredericksburg,va
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cudaman1969 Offline
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Hate to say it but I would venture over to the bow tie forums, got to go where the knowledge is on high hp-rpm small blocks, plenty of professional 1000+ hp small blocks built that turn 8000 to 11,000. I'm sure they have found what works and don't. Happy hunting.

Last edited by cudaman1969; 11/06/16 10:31 PM.
Re: which rod for a bracket motor [Re: rebel] #2191198
11/07/16 03:06 AM
11/07/16 03:06 AM
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aotearoa
rebel Offline OP
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I sent Tom an email n after an exchange of information he considers his rods to be up to the task. You think he's being on the level with me?

Re: which rod for a bracket motor [Re: rebel] #2191229
11/07/16 06:24 AM
11/07/16 06:24 AM
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Finalnd, Perkele
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jyrki Offline
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Finalnd, Perkele
I have used Tom's rods, run them for 8 years with 1500+ hp, no problems. They were checked for cracks two years ago and one had some because it had been hurt in a lifter failure, but never broke.


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