34 replies to this topic

[Madmax]

Im building a 1380 fast road engine, aiming for as much bomb proof reliablity/power as i can get (and i know thats a tough one)...


Should i use Arrow con-rods or Cooper S????

or are there any others?


what about shot peening and polishing?

[Guess-Works.com]

Only use cooper S rods if you want to use a stroked crank...

[Jammy]

I don't really think things like con-rods or cranks, etc are going to be the problem with reliability. I think the reliability issues with high performance engines come from them putting stress on ancilaries, things like starter motor, clutch, cooling system, etc.

Obviously though, the lighter arror the con-rods will lighten the rotating mass and so should be capable of reving freer? MiniSpeed had lightweight steel con-rods on offer for about £700 a while back?

But my suggestion in your quest for reliability is to make sure all the ancilaries are upto the power. Get an uprated starter motor. Make sure you use the right spark plugs, MiniSpares 2 core rad, silicone hose set and maybe an deep impellor water pump?

[siggy]

Innocenti rods are better than 'S' rods

Siggy

[Jammy]

Really? I thought they were the same? How are they different?

[Madmax]

aah, but why are innocenti rods better? are they better under stress?

[mambaman]

its all a bit of a muchness, inno rods are concidered better/stronger as they have a bigger crankpin diameter. Made of the same stuff as S' rods though (IIRC). Whatever rods you get, avoid the minispares S' reproduction ones, they are truely SH!T.




EDIT: i notice your concidering using arrow rods, if your going this way im taking it your thinking of a high revving race engine. In my opinion these are the only rods to use, dont even think about using minispares ones. I learnt this after buying some myself for a short stroke unit im building. If i had the cash i'd sell the minispares rods and buy some arrow ones, but funds no longer allow.

[Jammy]

Whats wrong with the MiniSpares jobbies.

[mambaman]

I have found:

1. They are massively unbalanced and require a large amount of time to balance/correct.
2. The big ends are machined in the wrong place in the forging and visually look uncentered.
3. They are HEAVEY at 750g+.
4.The little ends and the big ends are missaligned, 20 times over arrows highest tollerance.
5. supplied with useless bolts, need to buy ARP at extra expense.

Also 2 seperate engine builders have told me that some are cracked.

[Jackman]

Blonde question...

Are these for the tappets or somthing else...

[Jammy]

Con rods are the rods that attach the pistons to the crank... (in fact you can see one in my avatar!)

[Jackman]

Ta. Went blonde there.

[Madmax]

hmm. i wouldnt have considered minispares anyway methinks, Arrow were my first consideration, as this is going to be as close to race spec as i can possibly get....


ive got to keep up with jammy and minis84 on the track....

although this is a track car it will be used on the roads some times, which is why i want the best reliability too, i figure if i build it to the best standards, it wont let me down


as for the arrow rods, anyone know what they weigh?

[Jammy]

ive got to keep up with jammy and minis84 on the track....

Awww, ain't that cute! Although gotta say, the only way you'll keep up with me is if your in my passenger seat! :tongue:

[Purple Tom]

lets not start that again Jammy.....we all know you're going to be miles behind me....listening to the evocative Eaton whine..... :fear: :grin:

Oh, and Madmax, I thought you were going 1310? How come you've moved up to 1380? (if i've missed a post somewhere then ignore me)