Who has shotpeened rods?

[Flannelman]

Help needed with this

In the process of getting shotpeened, balanced silvertop conrods with ARP rodbolts. Pistions are standard, to be balanced as well. All were crack tested - pass.

Question is, what is the "safe" RPM limit of this combo? Im asking for people with experince with this set up or similar please.

[dnalunchie]

I ran this same set up in my AE101 "OHHBOY" at 9000 rpm for many months, no problem.

Larger fuel pump, blacktop cams and link ECU whole engine had been balanced much the same as yours. The question really becomes how high do you NEED to rev it to get the power you want.

With my cams there really was no need to rev higher than 8500.

[matt dunn]

Standard rods good to 8700, shotpeened rods good to 9000?

I dont think that it makes that much difference myself when i did a lot of research into it.

[rx7guy]

Shot peening increases the fatigue life which is related to the surface condition (cracks etc). As the surface is refinished during the process they should effectively act like new rods, just a wee bit stronger.

My theory anyway..

[Akane]

I thought rev limit is more related to how strong your rod bolts are, while shot peening can increase the limit it'll fatique (ie: bent rods from repeatitive high power runs)

[iOnic]

The question really becomes how high do you NEED to rev it to get the power you want.

+1. No point revving it higher if it isn't making any more power.

[frost]

for the price of getting all this work done, you better off paying another $150 for a set of h beams, (unless you have good hook ups)

i went through this debate about a year ago for my blacktop, had the rods all ready to go to ANZ, but the H rods are so cheap and SO much better its not a hard choice, look at spool or eagle, both at the same price of about $550 depending where you get them from, with arp bolts too,

[Brick]

i used ze rods on my old engine with arp bolts. Always saw 9000rpm and never had problem.

Mind you if your spending that much $$ on a engine to make power that power that high you may as well spend that wee bit more for decent rods as said above

[matt dunn]

i used ze rods on my old engine with arp bolts. Always saw 9000rpm and never had problem.

Mind you if your spending that much $$ on a engine to make power that power that high you may as well spend that wee bit more for decent rods as said above

I used silvetop rods and new geniune toyota rod bolts at about $3 each on one of my old race motors.
Went for 2 years of hard racing in my car without trouble till I sold the engine.

[Flannelman]

Its abit of an experiment at the moment.

Headflow numbers sugest power will be 9330. In theory at least. Was looking at 9500 limit.

Ive got connections for the work, and new rods suggest more rpm, so new forged pistons would be neeeded too. Costing $1000+ for only 500 more rpm till the oil pump is the issue...

Just testing stock parts, but trying not to build a silvertop hand grenade either.

More comments welcome on the subject

[Malcolm]

I'm curious to know how you've correlated flow numbers for the head to an engine speed you expect to see peak power (especially to a precision of 10rpm).

The manifolds attached to the head will have a big effect on where you see the power, as will the cams and how they're timed. On top of that, frictional losses can really start to add up at high engine speeds which would tend to lower the speed where you see peak power.

[4agtepwr]

I spent a lot of time linishing the beams of my rods and balancing them so they were all spot on and then had them shotpeened, along with arp rod bolts they seem to be fine, makes power at 9 grand and has seen close to 10 at the drags, 420hp to so no light load. Having said that ive never seen a modern jap "performance engine" break a rod through out and out horsepower, its normally a rod bolt that lets go or due to a run bearing.

[Flannelman]

http://users.erols.com/srweiss/tablehdp.htm

Headflow ive got is 210cfm.

Cubic inch of 4age is 98. Close enough to 25 each cylinder. Connect the lines, find 9332 rpm. Doesnt tell me how much tho.

Use as a guide, not a rule.

4agtepwr, thank you. Very helpful

[QikStarlie]

i use stock slivertop rods with arp bolts. 8900 limiter. and yeh it hits that EVERY time it gets driven.