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H beam rods


mikemunro
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Mike,

You should explain further what you mean.

 

Standard Triumph conrods ARE H-beam in section.

AND

Different conrods might clear a 2litre sump if it was fitted to a 2.5 cranked block, but it's the extra throw on the crank, that gives the extra stroke, that causes the problem.

 

Do you mean these?  http://www.ebay.co.uk/itm/Triumph-T120-TR6-T110-Connecting-Rods-Conrods-Steel-4340-Forged-H-Beam-/251500169215

If not, give us a link to the items you speak of.

John 

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Where does it say in http://www.ebay.co.uk/itm/for-Triumph-TR250-TR6-late-Performance-Con-Rod-Conrod-ARP-2000-Bolt-SALE-RPF-/141012672292  that these will clear a 2 litre sump?

Chris says it "may" clear - has he done this?

 

You have given us so little information, Mike - I presume this is a 2.5 in a small chassis car?   So you can't fit the 2.5 sump which will foul the front cross chassis member, and leave no room for the steering rack.  So you must fit a 2L sump, but that won't clear (but only JUST won't clear) the front two big ends.     Generations of Triumpheros have taken a hammer with a ball peen head to the 2L sump, often using the 'frog' in a brick as an anvil/mould.

The resulting two small bulges in the floor of the sump look 'meant' and certainly not 'mangled'.

 

Those sets of fancy conrods look very nice, but no one will ever see them any more than they will see the bottom of your sump.    At the same price for a set of 6 as they used to cost EACH, I have to ask were do the come from, and what is their quality?

 

I use Triumph con rods.  I remove the flashing and all the other skin imperfections, lighten the ends, balance and polish, and then shot-peen them.  I can do all this work with an angle grinder, die grinder and air sander, except the last and that costs about £60, £10 each.   But it's your money and time.

 

JOhn

 

PS Mike.  The above in blue is how to post a link.  It's really useful and saves a lot of time searching in Google

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Glad to help, Mike.

When I asked for more detail, I wondered if you were hoping to race this engine, because only V.high revving engines need this sort of thing.

If not, the standard ones will do fine.

 

A ball-headed hammer has a ... ball-shaped head,  on one side, the other usually has a flat face.

AKA "engineers hammer"

See: https://www.cromwell.co.uk/SEN5252150K

 

A carpenter's hammer is the cruder claw hammer.  Remember, it's carpenter's  who knock packing cases together.   The woodworkers who construct furniture are cabinet makers, and their hammers are light, delicate tools!

 

John

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yea got one of them and a complete hammer and dolly kit,  ive actualy got a sump which has been some what mangled by somone else so i might has well try and sort that out first. no jonh im not going to race it but i wanted more torque and some more bhp w'ill im at it , i had a disaster a short ago, i built up my gt6 mk 2 engine which was a early block redone everything except the oil gallary it had a newman 280 cam ,followers and springs to match 6/3/1 single big bore exhaust (bit loud)triple 40 webers, big valves, bronze guides from Chris Witor plus i ported and polish and port matched the gasket and manifold and it rolling roaded at 139.9bhp then on the way to newbury an oil gallary became blocked and compleitly wrecked the cam and two followers ,burned 1 piston and the side of the block and also 2 big ends and 1 main bearing. it had only done about 3000 miles :angry:  :angry:  :angry: luckaly i had a spare block and a 2.5 crank and 2.5 head so ive gone down that road this time hence all the questions some times it pays to ask cheers Mike  

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There is some stuff over on the CT forum a while ago about a very decent chap called Marcus. He rebuilt his engine, and paid plenty of attention to the oil galleries, including putting a VERY long drill right along them and drilling the problematic restriction through. May be worth a search?

Using similar stuff on a 2.5 should result in a very nice engine! 

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A definite worthwhile read!  And a marcus-style widened oilway is less likely to be blocked, but the big advantage is that it will have no lurking residues to come loose and block it.

But IMHO a thorough - and I mean thorough - clean with rifle bore brushes, detergent and HOT water can do the same.

 

The Kastner octopus is another way of overcoming poor oil supply.   KK found that at speed the front main bearing was starved.  He didn't know why - I suspect it was a crank resonance effect - but made up the octopus to supply oil directly to the mains, not through the gallery.      My approach is to avoid the complex octopus and just put an external line from the back of the main gallery to the front main, providing a different pathway that will resonate at a different frequency.

 

John

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If they are a Mr M Speed rods, then ye will most likely have to

cut away the bottoms of the cylinder aboot an 1/8th, in 2 spots.

this where the side of the rods are highest., so they fit into the slots cut into cylinder.

this cos the rods catch on the side, EVEN though there cut oot there as standard.

 

see this, page 4, reet at top

 

http://www.triumph.org.uk/cgi-bin/forum10/Blah.pl?m-1430424675/s-45/

 

M

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  • 2 weeks later...

"Seams"?  What seams?   The sump is pressed steel from a single sheet.  No seams.

 

Just for anyone else who wants to relieve a 2L sump to provide clearance for a 2.5 crank. no "blow torch" is required, and IMHO potentially damaging to the sump, by warping it.

Mark the areas that need to be dented, below 1 and 2 cylinders and with a ball peen hammer (see above) make a small, elongated dimple about an 40 x 5mm and 5mm deep.

Do not indent the area between the two dimples, or you will foul the steering rack.

The 'frog' in a brick makes a good anvil.

 

John

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yes i know its pressed out of one peice John, it was twisted, what i ment to say was it seems to be warped!!! as for using a blow torch it is a good idea as it softens the metal making it easier to work it, and yes it did fowl where the the rack is but that was put right again by heating the pan and re shaping with a solid bar, it also mis shaped the front of the pan slightly which again i heated  and straightened using a straight edge. i had to make three new bulges on the pan ,i put the sump on, no gasket turned the engine over and the con rod bolt marked the spots where i needed to work on.  PS  sometimeS if you work on cold sheet steel it can crack this is why its a good idea to use hea,t the steel becomes softer therfore more malagable every one to ther own so long as it work in the end. 

 

Mike

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Mike,

You started this thread telling us that you didn't want to "have to mangle my sump".

Now, you have beaten such a big dent in the floor that it fouls the steering rack and warped the sump!!!!!!!!!!!!

And then you heated it red hot with a gas axe, which made it worse until you heated it again.

 

Yes, work embrittlement is real, but on thin panels, you heat the bulge after creating it and before making it bigger, to anneal the metal.

Only the area worked needs to be heated, in this case about four square centimeters.

See: http://www.efunda.com/processes/heat_treat/softening/annealing.cfm

 

Mike, engineering is a light, delicate pastime, suitable for ladies.  What you have been doing is a blacksmith's job, or rather what a blacksmith's apprentice might do!

John

 

PS "three new bulges in the pan"??? There are only two conrods that can foul it.  Where do the other come from.

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