The Weekest Point (Bottom End)

[SeattleSy#1255]

I'm still learning about builds so excuse this thread if they are bonehead questions.

I know a lot of this depends on your goals, but i'm only talking strength, reliability, and power allowance.

1) is the weakest point of a bottom end the rods, no matter what you are using?

2) what is a properly treated stock crank worth HP wise 600-700?

3) if a build went: stock (treated) crank, Oliver Rods, and JE pistons is my weakest point now my crank and would it be worth going with a billet crank sice you have excellent rods and pistons.

4) using a stock treated crank, are you waisting money going with rods that are more expensive such as Oliver over Eagle and pistons, such as JE over SRP?

5) Basically i'm wondering what the weakest point is to a bottom end and maybe with a 15-20% increase in crank strength, is a billet crank worth it over a stock treated crank.

6) what is a safe HP range for a stock block?

Thanks for info...i'd like to plan things out, but need to start somewhere.

 

[jwaller]

Re: The Weekest Point (Bottom End)

rods and pistons are equally crappy. replace both with trw/srp, and eagles for a bottom end worth 500 easy hp.

stock cranks have gone 10's so easy 700-800hp.

if you dont wanna run low 10's a billet crank isnt needed.

eagles will do just fine for anything under 1k hp.

ed's put a stock block in the 9's so 1k hp is do-able.

weakest points are rods and pistons equally. replace those and a stock crank, stock block can go mid 10's without detonation.

 

[SeattleSy#1255]

Re: The Weekest Point (Bottom End)

john thanks...only thing i met in questions number one, was not neccessarly just syty's (I know our pistons/rods aren't to great), but any internal combustion engine, what is the weakest point from a physics standpoint?

 

[VermontTy]

Re: The Weekest Point (Bottom End)

john thanks...only thing i met in questions number one, was not neccessarly just syty's (I know our pistons/rods aren't to great), but any internal combustion engine, what is the weakest point from a physics standpoint?

Anything that moves as a result of an explosion; as John mentioned, pistons and rods. When you get down to it, combustion is where it all starts, and what makes stuff move, and if you can't reliably transfer the force of that explosion into rotational energy, then you're pretty much hosed. Talking straight physics-wise what's the weak point? Who knows. 10 people will probably give 10 different answers. The weak point will move though; if you put SRP's & Olivers in your truck, now the weak point isn't the piston and rod anymore, it's maybe the crank, or main caps, or bearings, or......

 

[ed hess]

Re: The Weekest Point (Bottom End)

rods and pistons are equally crappy. replace both with trw/srp, and eagles for a bottom end worth 500 easy hp.

stock cranks have gone 10's so easy 700-800hp.

if you dont wanna run low 10's a billet crank isnt needed.

eagles will do just fine for anything under 1k hp.

ed's put a stock block in the 9's so 1k hp is do-able.

weakest points are rods and pistons equally. replace those and a stock crank, stock block can go mid 10's without detonation.

yeah the stock block can go into the 9's but....

it will twist out of shape in short order.

you could try block filler and a mid-plate to avoid twisting.

But my understanding is its not the hp that kills the stock block but the twisting that will come as your 60ft start to drop into the 1.4's and 1.3's and below.

not sure how much safer your are with the bowtie block as for the twisting with low 60fts.

but what i have learned is that as you get into low 1.4's and faster you should add a midplate.

no one here has been doing low 60fts with as much hp as we have yet so only time will tell if you can twist bowtie blocks with 1.3x 60fts without a midplate.

i wont ever find out as i am in the middle of mockup on my midplate as I type this.

wonder at what point the solid motor mounts will let go from either the block, the frame, or from the mounts themselves?

ed

 

[VermontTy]

Re: The Weekest Point (Bottom End)

Stupid question alert.....



** Drum roll please..... **



What is a mid-plate, and exactly what starts twisting and deforming that you need one?

 

[ed hess]

Re: The Weekest Point (Bottom End)

Stupid question alert.....



** Drum roll please..... **



What is a mid-plate, and exactly what starts twisting and deforming that you need one?

the block twists...

from moroso comp eng. site

http://www.competitionengineering.com/catalog/CategoryDisplay.asp?CatCode=11073

Competition Engineering Mid-Mount Plates are designed to work in conjunction with our Front Motor Plates to eliminate torsional stress within the chassis. Installation of a mid-mount plate also allows easier transmission swaps, aligns the drivetrain to eliminate block twisting

hth

ed

 

[VermontTy]

Re: The Weekest Point (Bottom End)

I'd seen them before on hot rods and non-OEM engine installs (i.e. 502 in a '57, etc), and was under the impression that they were A) a fairly easy way to mount an engine in an older / custom frame, and B) cosmetic. I guess you learn something new every day.

 

[SeattleSy#1255]

Re: The Weekest Point (Bottom End)

Anything that moves as a result of an explosion; as John mentioned, pistons and rods. When you get down to it, combustion is where it all starts, and what makes stuff move, and if you can't reliably transfer the force of that explosion into rotational energy, then you're pretty much hosed. Talking straight physics-wise what's the weak point? Who knows. 10 people will probably give 10 different answers. The weak point will move though; if you put SRP's & Olivers in your truck, now the weak point isn't the piston and rod anymore, it's maybe the crank, or main caps, or bearings, or......

well your last sentence is what I was wondering...shifting the "weak point" from pistons and rods to the crank, is that a good idea or is a weak point a weak point and it doesn't matter. That is why I was asking if using better rods such as Olivers over Eagles and a better piston would now transfer that weak point to the crank if you are using the stocker (treated). Also why i asked if you are spending the extra cash for Olivers and a better piston, if you are wasting your money for the extra strength if you aren't going to go with a stronger billet crank?

Like ya said, its worthless if you can't transfer the torque, but from a physical engine building standpoint, if you are going to have a weak spot in the entire rotational mass configuration, is there a better place to have than another?

 

[VermontTy]

Re: The Weekest Point (Bottom End)

As mentioned by Ed and John, the rods and pistons sucked from day 1, and the stock crank has been proven to hold up under big numbers. Think of it this way.....

Pistons & Rods = 400hp
Stock crank = 700hp
Stock block = 900hp

Stop replacing stuff A) when you hit your HP goal, or B) run out of money, whichever comes first.

 

[ed hess]

Re: The Weekest Point (Bottom End)

amended list:

Stop replacing stuff

A) when you hit your HP goal, or

B) run out of money,

C) run faster than matt or robert

 

[VermontTy]

Re: The Weekest Point (Bottom End)

amended list:

C) run faster than matt or robert

I don't see hell freezing for me anytime soon.:roll: