Are they a worth while investment? (SRM conrods)

[Sluggo]

The MAP cycle rods are noted as 6.5 inches so that COULD be a problem,, 

But the specs seem really impressive otherwise.   I would have to do a lot of measuring and mock up before I could have an opinion on the rod center to center being a significant issue.

Specs:
Dimensions:

6.5 inches center to center
Features:

Sold in matched pairs - balanced to +/- 1 gram
Unmatched quality - the best rods available anywhere for Triumph
"Solid Works" designed and stress tested
Machined from 4340 forging
Shot peened for stress relief
ARP2000 bolts (220,000 lb. tensile strength)
Innovative machined piston oil squirting notches
Double wrist pin oilers
Unique reinforced small end critical areas without adding excess weight or cost
Finite element analyses design by High Cotton MotoWorks allows for:

Re-shaped pin boss for added strength (helps prevent "pin flex"& small-end failure)
Double “forced” pin oilers to reduce friction and piston pin heat
Bushed small end (replaceable) eliminating the need for fragile and expensive DLC pins
Optimized big-end and pin boss for strength with important weight reduction compared to other steel rods
Note:

Check center-to-center length on your existing rod to ensure proper fitment
BSA Models

BSA A10 Plunger 1956 - 1957
BSA A10 Road Rocket 1956 - 1957
BSA A10 Rocket Gold Star 1962 - 1963
BSA A10 Rocket Scrambler 1958 - 1959
BSA A10 Royal Tourist 1961 - 1962
BSA A10 Spitfire 1960 - 1963
BSA A10 Super Rocket 1958 - 1963
BSA A10 Swing Arm 1956 - 1963

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I dont know anything about the Thunder products but I know of a shop down in LA who used their Preunit Triumph cases and are pleased with them, set some LSR records with them as well (Franz & Grubb)

But it APPEARS based on the website the Thunder BSA rods might also be 6.5 as well??
-----------------------------------------------------------
Specs:

1. We are manufacturers and suppliers worldwide of Lightning Conrods, a high quality conrods made from 7075 T6 alloy available from stock to fit all popular British bikes suitable for road or race, used to win many Vintage and Classic Championships Throughout the world.
Available for the following bikes:

BSA B25, A7, A10 large and small journal, A50, A65, A75/ Rocket 3

Norton Dominator 88, 99, Atlas, Commando

Triumph T100 pre 54 small journal using Daytona B/E shells,

Triumph Daytona, 5TA, T100, T110, T120, T140, T150, T160

NRE 6inch centres, 6.5inch centres

Specials are also available to customer’s requirement
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British Cycle Supply (BCS) is another good vendor and I know the owner Mark Appleton.  (PM me for the promo code discount  )

and they stock the Carillo brand rods...

See: http://www.britcycle.com/Products/carillo_conrods.htm

Building A Hotrod Brit Bike?

Fatigue is the major cause of connecting rod failure. Carrillo Rods utilize a proprietary chromium / nickel / vanadium / molybdenum alloy steel and are manufactured and forged to custom specifications to meet Carrillo's stringent requirements for strength and durability.

Carrillo H-Beam Chrome Moly Steel Rods are designed with the serious racer in mind. Each rod is balanced and shot peened to achieve the ultimate in strength and fatigue properties and to endure even the most challenging conditions during high-performance competition.

The PRO H-Beam rod is the strongest connecting rod money can buy. No stronger rod is available anywhere at any price. It features a unique design that requires more machining operations than other designs. This design provides a rod that is not only stronger, but is up to fifty grams lighter than the inferior OEM rods it is replacing. However, the crown jewels are the Carrillo exclusive SPS Multiphase rod bolts.

These are the world's strongest rod bolts!! Under normal operation and service, SPS Multiphase bolts should last indefinitely. They have been tested to over 100 torque cycles without any fatigue loss. The combination of the rod design and the Multiphase bolt is the reason that the PRO H-Beams are the world's best rods.

The best insurance you can have for a bulletproof engine is the best rods in the world: US-Made Carrillo steel rods - light, strong and rigid. Don't take chances, call British Cycle Supply for Carrillo conrods for all British bikes. Huge stock on our shelves RIGHT NOW for most models!

The Carrillo connecting rod is a precision, high strength, quality connecting rod, which when properly installed and maintained, will perform faultlessly in today's racing and high performance engines.

The Carrillo conrods supplied by BCS:

06-4896/A        Conrods,    CARRILLO, Norton twins                PAIR
41-0549/A        Conrod,     CARRILLO, BSA B44                     EACH
65-1836/A        Conrod,     CARRILLO, DBD, ETC, High performance  EACH
67-1205/1206/A   Conrods,    CARRILLO, BSA A10                     PAIR
70-9525/B        Conrods,    CARRILLO, Triumph 650, late           PAIR
70-9740/B        Conrod set, CARRILLO, 3cyl, BSA/Triumph           SET
70-9915/A        Conrods,    CARRILLO, T100, B25, T25 late style   PAIR
71-1105/1106/B   Conrods,    CARRILLO, BSA A50/A65                 PAIR
71-1635/A        Conrod,     CARRILLO, B50                         EACH
71-3006/A        Conrods,    CARRILLO, Triumph T140/TR7            PAIR
71-7339/A        Conrods,    CARRILLO, Triumph TSS 8 VALVE         PAIR

© 2010 British Cycle Supply. All Rights Reserved.

[JulianS]

Potential problem of the extra 1 mm between centres could reveal themselves if you are using big inlet valves, high compression pistons, 357 cam, your head has been skimmed, your valve seats have been replaced to restore the geometry.

Possible result valves clashung with pistons. Or in my case the actual result.

[orabanda]

Forgive me for drifting a little off topic here, but there is a strong karma here, as Ariel ended up being part of the BSA family.

Waiting for installation in the engine in the months ahead, check out the pics of the set of new rods (CNC machined from billet) that the Ariel Owners MCC was able to supply; glorious!

Richard

[duTch]

 

..I will add this,, (Because I am pedantic and a bit OCD) the following:    ......

  No way   that never even crossed my    ...... mind  

 

     

[Sluggo]

okay, Ariel deviation,,

I am no Ariel expert, But I do have a little experience with them and still have a ton of photos of a large Ariel Sq4 collection I sold off on behalf of an estate deal.  I debated keeping one of the bikes for myself (A 48 I recall) but sold them all in one lot to a fellow in Scotland.

I was shocked examining the motor parts, (It was a large collection and every variant,) and the internals were SPINDLY and rather frightening to look at IMHO.. So improved rods would be a huge benefit

Side tangent, But I am writing a book related to this topic.  The Ariel Sq4 and Healey 1000 story.   My friend Sir Edward in the 1970s had a business partner Dick Thompson and they operated a multifaceted business called "Stop & Go!". They secured the rights to be the US distributors for the revived sq4s being built by the Healey brothers.  Dick Thompson LOVED Ariels, Also Lincolns and Jags,, Eddie was a die hard Norton guy.
Dick had been collecting Sq4s for 2 decades prior to the Healey Deal,, which went down in flames, mostly due to the Oil crisis in the early 1970s.  I have some scathing letters to those fellows in the UK and other documentation, as well as all the original company literature, brochures and company correspondence.
Suffice to say Sir Eddy and Mr Thompson (Some people called him "Speedy Dick") lost a LOT of money in their investment.

It is quite a rollicking tale and involves Kenny Dreer (AKA Dreary Ken) who went on to form Vintage Rebuilders and Norton America, Also Jay Leno.  (I own the remnants of Norton America as well, but thats a different story)

Sir Eddy called me and asked me to help out with the daughter of Mr Thompson who was struggling with aspects of the estate. I helped liquidate the Ariel collection and have extensive dealings and history with the whole debacle. 

Again, SORRY ADMIN!!! (my bad)

[KiwiGF]

Forgive me for drifting a little off topic here, but there is a strong karma here, as Ariel ended up being part of the BSA family.

Waiting for installation in the engine in the months ahead, check out the pics of the set of new rods (CNC machined from billet) that the Ariel Owners MCC was able to supply; glorious!

Richard

It’s a shame they are hidden inside the cases isn’t it  .When I got my thunder rods I was amazed at the finish, the material Thunder use (7075-T6) isn’t the easiest material to machine, yet you would need a magnifying glass to see any machining marks.

[JulianS]

Thunder Engineering rod  big end.

[bl**dydrivers]

What’s the length of standard factory OEM connecting rods?

Because I will be having a 357 Cam, do have a big Valve head (67-1549) and it most likely will require skimming/milling.

I would have thought they would have made standard length connecting rods!
Unless they lengthened them to raise compression aimed for racing.

[berger]

I got some thunder rods and they were etched with the date they were made which turned out to be the 6th anniversary of my heart attack. apart from that they are going in a shooting star motor with 375 cam and a gas flowed ss head with super rocket inlets,i do know to make this work the valve spring keepers have to be machined to stop spring bind, its always best to do a dry build to see if the rods bind in the cases and to look for other problems. I don't think a10s have any trouble with the high lift cam but a dry build could save hours of later work, you need at least 60thou of gap between the spring coils

[JulianS]

Standard con rod length is quoted as 6.469 - 6.467 inches (not 6.5 inches) between little and big end centres. Information from Bert Hopwood published in The Motor Cycle 3 July 1952.

If you put an R and R rod up against a BSA made one  or a Thunder Eng or SRM made one you will notice the difference.

[coater87]

 I put map rods in mine. They are rather nice.

 No problem with pop-up piston.

 I will let you know.

Lee

[BSA_54A10]

I've never really understood why 'billet' anything has much cachet.

*** SORRY ADMIN, Please forgive my off topic comment here***

Haha!   Well,, I find it amusing some of the rivet counters and "Anal retentive bolt polishers" get all worked up about stock cast pistons when billet or forged ARE better.  You would think Hepolite was Gods personal gift to man kind if some people are believed.  Rods??? Different animal though. 

My wifes company makes some amazing stuff out of all kinds of "Billet" and in very large volumes.  Just depends on what you need it for.     Would you like, alloy,steel, copper,Brass, stainless or????
See: http://www.enochmachining.com/

But in some places "Billet" is a dirty word and reviled.   I know these guys and I really like their events.

See: http://www.billetproof.com/

" Why do you hate Billet parts?
We dont. We respect the high tech side of the hot rodding world. This just isnt the show for those style of cars. Billetproof is for 50’s and 60’s styled hot rods and customs.
-------------------------------
I have an Aluminum intake on my car, can still come to the show?
Yes. Cast Aluminum parts are fine. Obvious machined billet Aluminum parts are not.
-------------------------------
RULES
1964 and prior TRADITIONAL style rods and customs ONLY
No visible billet anything! Especially wheels!
No digital gauges
No IFS on fenderless cars
No trailer queens
No mag wheel styles made after the 60’s
No high tech styled, pastel heart beat graphic, tweed interior, fenderless IFS sporting hot rods
Traditional looking choppers and bobbers ONLY! (No modern West Coast Choppers, OCC style bikes)

(Note: They LOVE vintage bikes as well, anything mid 70s and earlier welcome, especially vintage British)

Seeking metallurgically I have massive problems with "billet" and the inference that the word "Billet" means a better quality part.

When we had Bantam racers I used to supply them with back ends from the billets used to iron gas bottles from.
Some very interesting grain structures , wrong alloy but it was only a Bantam head so it did not really matter.

Now some companies who make "billet" products go to great lengths to totally redesign the parts they make to account for less than optimal grain structure orientation and size.
Having made extrusion billet for a few years, the grain structure will vary greatly till everything gets into equlibrium and remain that way till you get to the end.
Now we used to remelt the first 3 meters of each billet ( continously horizontally cast so unlimited length ) because it produced poor quality extrusions.

But when you come to billet machining companies I doubt just how many of them etch the billet first to check on the grains before they start machining.
Even worse are the new machines that allow you put the original part on a plinth then the machines scans the part.
You then plop a lump of metal on the stage and the machine makes an exact dimensional replica part.
Like a lot of cheap Chinese knock off, looks identical but not the same strength wise.

As for anything made from metal, the metal itself will have a finite life before disslocations within the crystals join together and the part self destructs.
It is called the fatigue life and is a property of the metal, not the manufacturing process, although poor design of the latter can substantially reduce the fatigue life even more.
So again any company that does not reveal the actual metal specifications should be considered suspect.
Even more companies who sprout "avaition grade alloy" another meaning less description.

Now for rods, a stress cycle is a revolution of the engine.
No intention to do the maths but we were involved in alloy wheels.
The racing Mags used on Ducattis were made from a material with a fatigue life of 10,000,000 cycles
That equates to about 18,000 miles which is more than enough for a track bike which would be lucky to do 10,000 miles in its entire extended racing life.
However the same ( Campligarno ) wheels fitted to street bikes were fatal.
From memory ( probably wrong ) the most fatigue resistant aluminium foundry alloy ( BP610 ) was 100,000,000 cycles of uniform sub critical low load.
And that is before you take into account the effects of heat , or adverse things like detonation so it is a no brainer.
If the engine is coming apart then the rods are going to get changed and get changed to a forged rod if possible.

[bl**dydrivers]

I put map rods in mine. They are rather nice.

 No problem with pop-up piston.

 I will let you know.

Lee

Lee, isn’t yours a Golden Flash with 355 cam and 7.5:1 CR Pistons?

Mine is a 1962 Super Rocket, with 357 cam, 8.25:1 CR Pistons and big Valve head (67-1549).
I’m very concerned about valve clearances and need to be certain before pulling the trigger on these.

Now I know to avoid the SRM billet allot con rods! I thought I trusted SRM and thanks to the knowledge on this forum I won’t be getting them.

Now I need to do more research on the MAP H Beam forged rods.

[Shark]

Hey Trevor, I had a Ducati with those dodgy "racing" wheels back in the late 70's!! The registration was cancelled almost overnight so those folk took it seriously shame the distributor (Fraser's) did nothing until the endless claims got the better of them. I have not been inside their establishment since . Sorry for the thread drift.

[BSA_54A10]

Hey Trevor, I had a Ducati with those dodgy "racing" wheels back in the late 70's!! The registration was cancelled almost overnight so those folk took it seriously shame the distributor (Fraser's) did nothing until the endless claims got the better of them. I have not been inside their establishment since . Sorry for the thread drift.

It took nearly 4 years to convince the DMT and the ADR that there was a problem with those wheels.
Even worse was the response of the Australian Government.
Cast car wheels for road use had to be made from BP 601 so it would be a simple change to the legislation to add the words "And motorcycles" to the ADR for cast wheels.

Apparently the 11 who died and the 30 odd who sufferred serious injury from the wheel collapsing were not enough to warrant 20 minutes of Parliament's time.  I would have thought 41 was about the actual number of them sold so if you had one they must have sold 42. It was the F1 750 replica from memory.
The number of riders who tell you thay owned one was about 10 times the total sold rather like H1's