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MG MGB Technical - MGB Rods Types - Photo Wanted?

Hello,

I've read this rather informative article:

http://www.sterlingbritishmotoringsociety.org/files/mgbtunings.PDF

On page 4 it mentions the various rods installed over the years into the MGB engines.

Extract:

The horizontally split connecting rods with balance pads used in the late 18GH through early 18V engines were a lighter 845 grams.
The final version of the connecting rod used in the late 18V engines had no balance pads and were the lightest, weighing 760 grams.
These can commonly be found on engines whose identification numbers start with 18V -883-AE-L, 18V -884-AE-L, 18V - 890-AE-L, 18V-891-AE-L, 18V-892-AE-L, or 18V-893 -AE-L.


I assume this article is correct that there are two types of 18v Rods, one with and one without the balancing pads.

Can you just lighten the earlier 18v rods down by (845-760=) 85 grams or more? and still maintain their strength.

Out of interest if a Carrillo rod is good for approx 150BHP per rod and say and MGB race engine puts out 40 BHP cylinder, then what is the approx BHP rating for a standard 18v rods before it breaks?

Could someone post a photo of the two rods side by side please and let me know more please?

Thanks
Mark.


Mark Hester

Hi Mark

Not really safe to lighten the 'padded' rods to the non padded ones, much lighter/slimmer design. We have been happy with the usual 18v rods at 160 at the wheels using arp rod bolts.
cam1588E is the part number of the non padded rod.

The non padded rods seem quite rare but I believe Chris Betson at Octarine services may have a few sets, maybe he would sell some if you asked him nicely?

Peter
peter burgess

Hi Peter,

Thanks once again for that info.

Moss once listed BHM1106 as a replacement for cam1588E but I asume they are no longer available new?

http://195.40.86.51/priceguide/oct_03_price_guide.pdf

Chris if you pick up on this posting.

Any chance of a photo of the two rods side by side please?
Or anyone else who has them?

Thanks
Mark



Mark Hester

Hi,
I'm french, sorry for my vocabulary
I modify rods with pad for my 1840 much tuned, by the time the engine works well
Conrods small end are bushed , I use forged piston (JEpistons) with floating pin, I use also ARP bolt
Best Regards
michel

dujuvejd

pic attached.Biggest problem I have had with the non pad ones is trying to balance sets!

Peter

peter burgess

Many thanks for that photo Peter.

Our of interest Michael, how light did you get that earlier 18v rod down to in grams?

Thanks
Mark
Mark Hester

Hi Mark
Every con rod weighs 690 grams with rod bolts
Best regards
michel
dujuvejd

This thread was discussed between 06/01/2010 and 08/01/2010

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