SpeedMaster Oldsmobile 455 H-Beam conrods

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Big Cadoo!

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What vehicle(s) do you drive?
Allegro
6.735 length Fits Stock Cad500 rod journals Custom forged pistons with compression height and
980 wrist pin diameter to suit installation. Measure from top of block deck to wrist pin. Substract 1/2 wrist pin diameter for final dimension. Zero deck height. Lift and duration and heads being used. I use CadCompany to order.Makes for no mistakes. These are for the 120cc heads with the studs and rockers with the stud girdle. Hoping for T- Bucket type fun...
 

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Big Cad in a bucket? You're just as nutty as I am! Big Cad in an Austin A40. These engines in such short wheel base cars and no weight? Seems like FUN!
 
Austin A40? Can you send a picture.
 
Austin A40 Dorset. About 2200 lb. and 90 in. wheel base.
 

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What's your take on aluminum rods?
 
I dont have a take on that. I had a Triumph 650 bonneville that I rebuilt and it had aluminum rods. Anytime I throttled it I envisioned the conrods bustin loose. Never happened though. The steel H-Beams were/are available for realistic prices so Ive used them mostly. My first stroker kit was from Larry Kruzick and it came with 6.760H-Beam rods for Chrysler big block rebushed for ford 429/460 wrist pin to use a 429/460 piston.
 
I have run Aluminum rods since 1975. For many classes of drag racing it is the best rod type to use. Most every other type of racing class uses some form of steel or Titanium. You can run them on a street engine that has light weight pistons and medium weight pins and rarely sees heavy deceleration loads to the rods. Small block ford or chevy they can be made to work if clearance issues do not pop up.
Big inch street engines , I would run steel. On the street it is just for bragging rights in my opinion. You would be much better off with a quality steel rod of the correct size. For me it was quite a learning curve using them. In the early days it was a guessing game when they would come apart and window the engine. We slowly learned about using different alloys and fasteners. There are only a couple of brands I will use now some of the brands I used to like went out of business when the Patriarch of the business died (Venolia , Brooks, Childs&Albert) are the ones I used years ago. Now I only do business with GRP or BME. I would consider R&R rods or MGP. All others , not. Special maintenance procedures are used to get the best use from the rods with out suffering catastrophic engine damage due to rod failure. After every outing the rods get check for thread fit with a nogo gauge. If it screws in , toss the rod. The rod bolts get checked when new for free length and when torqued . This is logged in engine log book (each bolt and what position on what rod) . Also the torqueing technique has evolved through the years of learning. We now just pull them up snug with lube on the threads. Then pull to full torque and check bolt stretch . If it passes the stretch test we send it. There is even more I could list that is done but I think you get the Idea . If it is a street engine that will stay together for several years go with steel If you are drag racing then aluminum Might be the choice . One other thing Good Aluminum Rods are $1300 and up for a set. Really good quality steel rods can be had for less with out the short life and maintenance. I will say this I do know of one small block Impala bracket car that put 100,000 miles on a set of BME rods . The car was a daily driver for Anne Tillman out of central Florida. She bracket raced every weekend and drove it to work during the week. The pan did not come off for 10 yrs. The engine never saw over 5500 rpm and ran through a powerglide trans. If you want to run Aluminum on the street buy some from one of the best and have at it. But at least go into it with a working knowledge of the true character of Al rods.

That is my take, now back to my cave.
 
Any Cad engine I build now will use a set of (425 Olds ) 7.00" Molner rods. with either .980 or .990 pins and keep the crank pin diameter stock Cad. Or if it is a stroker I will run a 7.1" BBC steel rod from one of several sources. The longer rod allows a shorter pin height and lighter piston.
 
That Austin is superb. Looks like it needs a Cad500.
 
Yes it do. Like I said, short WB cars and no weight should be interesting.
The reason why I was thinking aluminum rods.
1. To lower the weight of the rotating mass.
2. Grab RPM faster.
3. Lower the shock to the crank. Yes, forced induction on E85. Injection is nice, but I'd rather be BLOWN!
 
48Austin said:
Yes it do. Like I said, short WB cars and no weight should be interesting.
The reason why I was thinking aluminum rods.
1. To lower the weight of the rotating mass.
2. Grab RPM faster.
3. Lower the shock to the crank. Yes, forced induction on E85. Injection is nice, but I'd rather be BLOWN!
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It looked like the distributor is at rear of engine and sbc headers. Confused me as it Big Block Cadillac forum. Maybe a better picture.
 
gordon said:
Any Cad engine I build now will use a set of (425 Olds ) 7.00" Molner rods. with either .980 or .990 pins and keep the crank pin diameter stock Cad. Or if it is a stroker I will run a 7.1" BBC steel rod from one of several sources. The longer rod allows a shorter pin height and lighter piston.
Click to expand...
I have 7.1 BBC H-Beams on a Moldex 4.6 stroke crankshaft in a Potter boogieman head engine. Loaded with top shelf components.I will sell that engine for a price satisfactory to both partys.
 
Big Cadoo! said:
It looked like the distributor is at rear of engine and sbc headers. Confused me as it Big Block Cadillac forum. Maybe a better picture.
Click to expand...
No, you are right. For now it has sbc. Working on Cad engine to put in it.
 
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48Austin said:
Most Dorsets are left hand drive. Since most were sent here or Canada. Bro D where you been hiding? Cadoo, what do you think of these? https://www.ebay.com/itm/152466114709
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Money wise the Olds H-Beams were less cost. The eagle Olds 455 H-Beams are much more money. Still offshore forgings finished machine/heat treat here I was told.
If your using custom pistons make up difference in compression height in build sheet. 10.813 stock Cad500 deck height. If you blueprint the build you install pistons on 4 rods at each corner on crankshaft on bearings in engine block if the Cad500 rotating assembly comes as a unit. Then measure piston depth then disassemble and have block decked. Thats one way. I have block deck machined for new gasket surface. I then have crankshaft on bearings in block with rods with wrist pins at 4 corners to check average compression height. I cant control perfect paralel to crank center line as I dont have that machine I get what the machine shop finishes. +-.005. I use that dimension in piston build sheet. I think the falcons have ARP2000 Bolts. The rods I just bought have 8640 bolts. You can piece together components or call Courtney at CadCompany and get everything in one package ready to go. He took my information for 4 different sets of custom pistons so far and they were exactly what I asked for.
 
gordon said:
Any Cad engine I build now will use a set of (425 Olds ) 7.00" Molner rods. with either .980 or .990 pins and keep the crank pin diameter stock Cad. Or if it is a stroker I will run a 7.1" BBC steel rod from one of several sources. The longer rod allows a shorter pin height and lighter piston.
Click to expand...
I was told the Cad500 factory crankshaft ground down to BBC rod journal diameter weakens the crankshaft to where it fails under high load applications. All the Cad500 factory crankshafts that are stroked are BBChrysler rod journal diameter. I have a Moldex billet 4.6 stroke x 2.200 BBC rod journals with 7.1 conrods because of not wanting to have crankshaft break.
 
That was a major reason I went with the Molner Olds 425 Rods . The big end requires no cutting down of the crankpin dia.. I looked for Chrysler 7.1 rods and found none available at the time and the Olds were only .100" shorter. OK by me. and the quality I think is much better than Eagle or Scat. Race tech/ Auto tech made my pistons for me. All is well. If I had known you would sell your combo before I started dumping money into this one I think life would be different now. I am still curious what you would want for your engine with the moldex crank. If you want to send me a PM that would be cool. I am getting ready to punch out of work and retire so I have to watch the funds.
 
gordon said:
That was a major reason I went with the Molner Olds 425 Rods . The big end requires no cutting down of the crankpin dia.. I looked for Chrysler 7.1 rods and found none available at the time and the Olds were only .100" shorter. OK by me. and the quality I think is much better than Eagle or Scat. Race tech/ Auto tech made my pistons for me. All is well. If I had known you would sell your combo before I started dumping money into this one I think life would be different now. I am still curious what you would want for your engine with the moldex crank. If you want to send me a PM that would be cool. I am getting ready to punch out of work and retire so I have to watch the
Click to expand...
 
Whats a PM? My drag race connection passed away. So I might as well sell it. Guys with other brands treat my like a leper. Cad500 guys Wanted to put in a 100 foot drag machine with some Ford guys but they had Ford on the brain. Ive got the th400transbrake tranny too would have built the headers too,but... I gotta down size.
 
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