Rod Lightening

[Gus 5]

not the phenomenom, but where would i get a set of rods lightened in auckland? wise idea in regards to loss of strength?

[Neal 546]

Lyn Rodgers Automotive (09 534 3363) is up your way and has an excellent reputation for building race engines. NA engines his specialty

His shop should be able to advise on best treatments to retain some of the strength when removing metal

(EG shot penning / polishing etc )

[kerrynzl 3]

the quickest way is to leave a rod-bolt out [it lightens the block too]

Otherwise Do it yourself

1: Polish the Beam LENGTHWAYS until smooth [never polish across]

2: Get them Shotpeened

3: fit New Bolts

4: Get them Balanced

5: Get the Big-End Resized [Tunnel Honed]

In that order [resizing doesn't affect balancing, but balancing can make the Tunnels Oval]

Remember If you don't Shotpeen them, because you have polished off the surface hardening they will break

Otherwise Call DOUG'S ENGINEERING in Subway rd Pukekohe [He does the lot]

[Gus 5]

sounds expensive...cost? any idea of the amount of material they can typically take out?

will probably give it a miss this time round...it is only a practice build anyway!

[kerrynzl 3]

I forgot to Add the First step ....................GET THEM CRACK TESTED

And New Rod Bolts

Shotpeening & Resizing costs between $25 & $50 per rod. on a V8 thats almost $400 [New EAGLE H-Beams cost about $700]

[nazistaffcar 0]

1: Polish the Beam LENGTHWAYS until smooth [never polish across]2: Get them Shotpeened

3: fit New Bolts

4: Get them Balanced

5: Get the Big-End Resized [Tunnel Honed]

I forgot to Add the First step ....................GET THEM CRACK TESTED

And New Rod Bolts

Try Bob at Balancing Specialists in NewLynn, because balancing an engine is probably more beneficial than polishing..... in all honesty its an ancient artform that is almost lost and most people remove wayy too much material especially when you consider that engines that are given this type of treatment usually have light weight pistons, gudgeons and super skinny rings.....there is a balance between your piston + gudgeon weight versus con rod get it wrong and you're guaranteed a big boom boom and there will probably be more than 1 leg out if bed......if you know what I mean.....

[kerrynzl 3]

Try Bob at Balancing Specialists in NewLynn, because balancing an engine is probably more beneficial than polishing..... in all honesty its an ancient artform that is almost lost and most people remove wayy too much material especially when you consider that engines that are given this type of treatment usually have light weight pistons, gudgeons and super skinny rings.....there is a balance between your piston + gudgeon weight versus con rod get it wrong and you're guaranteed a big boom boom and there will probably be more than 1 leg out if bed......if you know what I mean.....

YEP Bob Mead is one of the best in the Business, I agree with you about polishing Rods [never seen any HP gains] What Gus was asking was about lightening rods. [if you're gonna remove metal, take the stress risers off the beams] Personally I consider polishing a waste of $$$ [when you add all the costs involved ,a set off H-beams ends up cheaper]

Horsepwer is Torque x RPM [lightweight rods will allow an engine to rev more, it's the revs that gain the HP,if the engine will flow the increased amount of air]

[Guest Spargo]

YEP Bob Mead is one of the best in the Business

He knows his sh*t. He did my flywheel (first e30 one he'd ever done )and it came out mint. He did Tony's also i think.

[westy 614]

Yup and an excellent bloke to deal with too.

[nazistaffcar 0]

YEP Bob Mead is one of the best in the Business, I agree with you about polishing Rods [never seen any HP gains] What Gus was asking was about lightening rods. [if you're gonna remove metal, take the stress risers off the beams] Personally I consider polishing a waste of $$$ [when you add all the costs involved ,a set off H-beams ends up cheaper]

Horsepwer is Torque x RPM [lightweight rods will allow an engine to rev more, it's the revs that gain the HP,if the engine will flow the increased amount of air]

To my understanding lightening/polishing rods is essentially the same animal, it involves the removal of material whether it be casting imperfections or token lightening.....afterall a lightened rod will surely be the time bomb if left in the hands of an over zealous 'race' engine builder.....I have spoken to Bob about this matter, even took a couple of rods to him and he reckons the cost will overshadow the performance gain. To be honest Gus both Bob and I think it would bee a better option to check out later model rods and see if you can find a matching late model animal which are lighter and made from better materials.....need to get workshop info and do some cross checking!!!

[Gus 5]

yeah, it starts getting expensive

m50 and s50 rods work and are lighter...its just availability.

im sure i could get some h beams as kerry mentioned above for not much more money

using an m52 crank and rods sounds like a good idea..but then why not just use the whole engine!

[westy 614]

If youre using crank and rods you will need the pistons to wont you?

Then after all that youve built a 2.8 without the benifits of the alloy block and 4v head for the same cost as an m52.

[Guest Spargo]

If youre using crank and rods you will need the pistons to wont you?

Then after all that youve built a 2.8 without the benifits of the alloy block and 4v head for the same cost as an m52.

he's got you there! But i'm guessing Gus want to investigate the benefits of a 2.8 connected to TCD's RHD manifold.

[Gus 5]

yeah sorry that was the point i was trying to make...m52 crank/rods + custom pistons would start getting $$

since my m42 is changed cars (a lotta plans for a little engine) m20 med compy 2.7 sounds fun

[westy 614]

How did the swap go Gus?

[Gus 5]

change of plans..doug made me an offer i cant refuse

will still be using the throwout bearing!