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#1
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Molnar rods and cranks
I would like to thank Tom Molnar and Ed for going out of their way to make us fine Pontiac rods and cranks for our old dinosaur engines.
They went out of their way to make us a custom batch of 3.25 x 4" forged cranks for us, Who else would do that ? They are anything but street only rods. Their basic BBC rod so many of us use is stronger than any OEM block. That rod has also been successfully used on race engines making more power than any NA Pontiac has ever made. More than good enough for a street car. Crower billets are over 1900$ now and Olivers are over 1600$. Fine rods for sure but the price tag puts many folks out of that market. I know 3 people who are running them on 9 second and low 10 second cars. I know of no people who have ever broken one. They make 3 different Pontiac rods. All 6.625. All with .980 pins. One with BBC big end. One with Pontiac rod end. And one press fit. And a Pontiac can not hurt them. Molnar rod on left, I beam in center and generic H beam on right. Thanks Tom Molnar. Last edited by Dragncar; 03-24-2023 at 04:17 PM. |
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#2
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Quote:
Stan
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Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#3
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Molnar connecting rods are fairly new to me but I do have a number of engines out in circulation with them and zero failures. Also zero issues in the build process. They are the best Chinese connecting rods I have ever used hands down. Of the 6 sets I have been personally involved with, none of the rods required any re-work or honing or special, hard to get bearings for proper oil clearance. They have all been very accurate, to .0001". Nothing like Eagle, Scat and the others. Just last week we had to hone .002" out of the small ends of an entire set of Pontiac Eagle rods. Completely unacceptable IMO. Highest HP of the 6 engines we built was a Ford. It made 735 HP @ 7000 RPM. A long way from John Langer power, but this was a street build for a Mustang.
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#4
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We all know what Mike Leech did with the help of Scott and Marcella. Who am I to say Scott is wrong ? I mean, if I were to ever try and make 1600 HP it would be with some high dollar aluminum or billet steel rod. But just the fact they can take power like that tells you they are more than good enough for any Pontiac build using a PMD block. The other brands have much larger and better aftermarket blocks and heads, maybe that has something to do with it. But there is no reason to drag Molnar through the mud as only being good enough for a "street cruiser". Kind of seems like they are good enough for and fire breathing Pontiac engine to me. |
#5
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I picked the Molnar "power adder" rods for my road race engine. Deciding factors:
1) wanted a steel rod for long-term durability 2) impressed with Mike's experience with them being spot-on for machined tolerances 3) I want to be able to run the snot out of this car without worry; so the small extra cost for the power adder version made for very affordable overkill. 4) the ability to talk to Tom personally, instead of a generic tech line at a private equity conglomerate. Eric
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"Everybody has a plan until they get punched in the mouth" noted philosopher Mike Tyson Life begins at the end of your comfort zone. “The mind, once stretched by a new idea, never returns to its original dimensions.” |
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#6
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Quote:
Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#7
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We currently have a set of Molnar 6.125" "Power Adder" H-Beams getting ready to go in our 1800hp 408 Small Block Chevy with a gear driven F3D-106 Procharger running on Methanol going in our small tire Pro 275 radial 1971 Trans Am. Lots of people making huge power with the Molnar rods/cranks nowdays. I've seen people running the Power Adder Plus rod at 2500hp+ without issue. I spoke directly with Tom Molnar about our application before purchasing the rods, and he said the regular "Power Adder" rod that we bought would work just fine in our 1800hp/8000 RPM application. Unfortunatley, they do not offer the "Power Adder Plus" rod for the Small Block Chevy application as of yet, only the "Power Adder" series, or else we would have went with the "Plus".
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1978 Trans Am Pump Gas 461 Stroker |
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#8
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Quote:
Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
The Following User Says Thank You to Stan Weiss For This Useful Post: | ||
#9
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Quote:
In sure you have all aftermarket parts, including the block. Back when folks started robbing the cracks to put in 350 blocks, they were afraid of the overheating block stories. I've never experienced any problems.
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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
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#10
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If you look up their lineup of BBC rods so many of us use, the standard 6.8 rod is 749 grams and 727 $. The Power Adder 6.8 is 817 grams and 789 $ And the Power Adder + 6.8s are 881 grams and 1118 $ Its pretty obvious this company is making rods for serious power. Anyone putting a 881gram rod in their engine is planning on making steam.
https://www.molnartechnologies.com/d...onnecting-rods Tom took a hour out of his busy day once and gave me a education on steel cranks and rods. Grain flow, and how rods fail. Wish I would have recorded it, that talk was so good. I tried to convince him to make us Pontiac guys a fully counter-weighted forging. Like the BBC ones he sells for 1200$. We would pay 1500$ for a crank like that, no problem. https://www.molnartechnologies.com/d...c-crank-shafts He gave me the reasons it would be tough to do. Its well over a 100,000$ investment up front. 50,000$ for the dies if made offshore. And the rest to make a run of 100 cranks. He said it would take him 10 years just to make his money back our market is so small. We need to take up a collection, Go Fund Me. Or maybe a rich member with 100K burning a hole in his pocket ! If 100 of us got together maybe he would bite ! |
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#11
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When forged cranks come up, there is often talk of a single set of dies being used to make multiple platform crankshafts. Pontiac and Ford FE, as well as Oldsmobile have some similarity and possibly share the cost of a die set. I would assume Tom is aware of this but maybe hasn't considered it for a new project?
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#12
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Tom Molnar is a very sharp individual ... here is a lengthy read of the conversation we had when we were purshasing his rods for our 1800hp Procharger application ...
Tom Molnar .... "Below is what I tell people when they ask about how much power a rod can take. Regarding HP ratings, we are asked this question very often but there is no easy way to honestly answer it because NO ONE HAS EVER BROKEN A ROD (or a crank) from horsepower. While there are a lot of people who rate rods by power, these ratings are simply a fake number that they provide to sell their product. I have been designing rods for over 37 years and I can tell you that NO ONE can honestly tell you at a certain power level the rods will break. First off, the load on the connecting rod in an engine making 800 HP with a 3.250" stroke is completely different than the load on one making 800 HP in an engine with 4.000" stroke. In most cases the people who are giving out these numbers are reading from a script, giving you a quick answer so they can get your money and go on to the next caller. These horsepower “ratings” come from the misconception that power goes up from higher and higher cylinder pressure pushing on the piston which then pushes on the rods. The fact is, maximum cylinder pressure pushing on the piston takes place at peak torque then goes down as RPM continues upward past this point. The reason HP continues to go up past peak torque even though the push on the rod does not is due to more power pulses per minute. HP is a calculated number based on torque and RPM not due to force on the parts. Torque is work done, HP is work done over TIME so with more pulses per minute, the HP number goes up even though the push on the rods does not. Next, if you ever see a broken rod and look at it closely, you will see it is not crushed but actually pulled in two. This high tension pulling load takes place at top dead center of the exhaust stroke when the piston changes direction and is due to the weight of the piston trying to go through the cylinder head and the crank pulling it back down. You are not making any power on the exhaust stroke. The heavier the piston, the higher the RPM and the longer the stroke, the higher this pulling load will be. Also if you ever see a dyno sheet you will see the power peaks then falls off but connecting rods will normally break at high RPM when the engine is making less than peak power. If power broke the rod, it would break at the peak not when it is making less power. Also in most cases the rod will break at the end of the straight away or the end of the quarter mile when the throttle is suddenly closed. Since you are not making more power with a closed throttle, I challenge anyone who rates rods by power to explain this to me and where they came up with their rating. In all of the years I have been doing this, I have not found anyone who has been able to explain where they came up with their numbers. The simple answer to your question about our rods, we have people who are making more than 1,000 HP with our standard weight rods and over 1,800 HP with our PWR ADR™ rods but I am not aware of anyone who has broken one, so if there really was such a maximum power number, we have no idea what it is because no one has reached it yet. One major difference between us and the other people selling rods is we provide honest information rather than quick, get your money type of answers. The bottom line is, if someone tries to sell you rods based on any kind of "rating", be very skeptical because they either simply do not understand the loads and forces on the parts they are selling or are telling you something that is not true so they can get your hard earned money."
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1978 Trans Am Pump Gas 461 Stroker |
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#13
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Quote:
Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
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#14
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I did not know that some Pro Stock guys are going with steel rods. There is a tiny bit of power to be had and in that world that is enough to win. His explanation of rod breakage was also very interesting. What happens first in a engine blow up, breaking it all down was fascinating. Turns out, a lot of the time the pin rips out of the piston first and people blame to rod. Tom is a very interesting guy and calls customers, potential customers back without any BS. Can not ask anymore then that. |
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#15
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Remember Pro Stock is a different animal. It has a min that the rod must weigh. Once someone was able to make a steel rod at that weigh that would live they started to check them out. Different rod materials offer different advantages. Where Tom talks about on the exhaust stroke ATDC the piston wanting to pull the top of the rod off (rod stretch). The steel rod will stretch less than an Aluminum rod which means they can set the piston to head clearance tighter.
Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
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#16
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Tom also sent me the picture of the cutaways of the beams, just as Dragncar posted in his orginal post, and explained to me why his are superior to the other designs. It definitley made total since after studying the cutaways. His design looked to be much thicker in the most important areas, and all around a much stouter looking piece comparing them to a standard common H-Beam(we own both). He also advertises his rods as "4340 Billet" material, where as your normal H-Beam designs are advertised as "4340 Forged" material.
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1978 Trans Am Pump Gas 461 Stroker |
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#17
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Tom was giving me things about different rods he had issues with in their construction. Good points and weak points.
What was surprising is he thought there were things even Carrillo could do better. They have been considered the best of the best for a long time by many. Make some 3-4000 $ steel rods. I do know some people who have broken a Carrillo rod. Still do not know of anyone who has broken a Molnar rod and post #12 confirms Tom does not know of any broken either. Does it mean Molnar are better, no. But it does mean Molnar rods are not just for street cars. They are in fact strong enough to take the HP most of us could ever make. And come on size, no re working needed. Every single offshore set of rods I have ever bought has needed something from a machine shop. |
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#18
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One of the reasons I decided to try Molnar connecting rods was meeting and talking with him at PRI several years ago. Straight shooter IMO. Proud of his products but he has knowledge, facts and a track record to back it up. He comes across as the "Bill Miller" of steel connecting rods. He also gets lots of bonus points for making a quality crankshaft for our Pontiacs.
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#19
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R 70 Judge.....I looked for a 4" stroke crank on the Molnar site and did not see one....
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#20
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Quote:
http://forums.maxperformanceinc.com/...ghlight=Molnar
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Will Rivera '69 Firebird 400/461, 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears ‘66 Lemans, 455, KRE D-Ports, TH350, 12 bolt 3.90 gears '69 LeMans Vert, 350, #47 heads: work in progress |
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