Fairly Noobish Questions

[justin321]

I think I want to change out my engine block and was wanting to know a few things.

I know that an iron block is gonna be heavier than an aluminum block but that it will also handle more power and higher heat better. How much of a difference is it realistically?

What is the difference between a short block and a long block (don't tell me that one is long and one is short lol) obviously there has to be advantages and disadvantages to each otherwise they would only make one.

If I'm going to add power adders, either a SC or TT kit should I do a LS7 or would I be okay just doing a 427 LS3 stroker. Will an LS7 work with the existing transmission?

Any additional info that you guys have would be great, any kind of considerations I may not have made to other equipment that will need to be upgraded etc; I would like to be over 700rwhp and money is not really an issue. If there's easier ways then help me out.

Thanks guys

[justin321]

Is 700rwhp even attainable without going to the extreme?

[justin321]

Bump

[SSE 4 2SS]

Originally Posted by justin321

I think I want to change out my engine block and was wanting to know a few things.

I know that an iron block is gonna be heavier than an aluminum block but that it will also handle more power and higher heat better. How much of a difference is it realistically? This part I can't tell you in any specific detail, but the cast iron block is where the really high HP guys go. That having been said, my build intention is in the 850 RWHP range and I am going to just build my current LS3 block to handle it. The block will be fully prepped up to and including the sleeving of the cylinders. It will have all forged internals and I am forcing the respirations with a twin turbo set-up..

What is the difference between a short block and a long block (don't tell me that one is long and one is short lol) obviously there has to be advantages and disadvantages to each otherwise they would only make one. A short block is a block only, without the heads. a long block consequently has or includes the heads. Depending on the manufacturer, you can specify a variety of heads to complete your long block based on the expected type of driving you intend. There are literally as many different heade designs as there are manufacturers. A good engine builder will often take a set of performance heads and tweak them even more for flow... More in equals more out, so more power...

If I'm going to add power adders, either a SC or TT kit should I do a LS7 or would I be okay just doing a 427 LS3 stroker. Will an LS7 work with the existing transmission? Again, you can get into differing opinions, but I've usually heard a stroker is not necessarily what you want for a forced induction motor. Strokers to my knowledge, which is very very old school is for getting a motor to match the other components. For example, the cam and intake manifold may be for a specific RPM range, and a stroker motor may allow you to stay in a given range for a longer period of time while still making power. I also believe that stroker motors tend to spin up faster, which is not a bad thing...

Any additional info that you guys have would be great, any kind of considerations I may not have made to other equipment that will need to be upgraded etc; I would like to be over 700rwhp and money is not really an issue. If there's easier ways then help me out. My builder and I are in the closing stages of build discussions, and I am scheduled to drop my car off in early to mid Janurary. He is going to have the short block as well as the heads completely reworked. With forced induction the factory springs may not be enough to close the big valves against the air flow as rapidly as they should. Floating valves are a big problem. Stronger springs that are evenly measured and matched are necessary. There are other components that need to be addressed as well on the heads. The block will be spinning forged internals, which are substantially stronger than the factory cast components. these include the crankshaft, the piston rods and the pistons themselves.

The factory exhaust manifolds are strong, which is great for hanging Turbos off of, but they may be somewhat limiting in their flow characteristics. Therefore, it is our intention to build one off stainless manifolds with half inch flanges and mandrel bent tubing all hand welded... No sense in having 1500 HP worth of turbos driven by 600 HP worth of manifold...

We are also going into the driveline components but you didn't ask about those so I'll leave it at that...

Thanks guys

Hope this helps a little....

[BlissStreet]

Are you asking the difference between Big Block/Small Block? or Short Block/Long Block? It seems people often get the two crossed and confused.

A short block is the engine block plus rotating assembly. A long block is the short block plus the heads, valve train and the cam. You still need to add the accessories to a long block. Short block < Long block < Crate engine. One is a building block of the other. So they don't actually make 2, they are simply the differing levels of build for any engine.

Example: This is a short block. This is a long block. And this is a crate engine.

Hope that helps.

[SSE 4 2SS]

Originally Posted by BlissStreet

Are you asking the difference between Big Block/Small Block? or Short Block/Long Block? It seems people often get the two crossed and confused.

A short block is the engine block plus rotating assembly. A long block is the short block plus the heads, valve train and the cam. You still need to add the accessories to a long block. Short block < Long block < Crate engine. One is a building block of the other. So they don't actually make 2, they are simply the differing levels of build for any engine.

Example: This is a short block. This is a long block. And this is a crate engine.

Hope that helps.

I did fail to mention the rotating parts, ooops, but yes, what he said...

[VonDutch]

First tell me how to get to a place in life where money is not an issue lol

Secondly an iron block will add about 55-60lbs to the chassis

I'd do a stroked forged bottom end motor

And then add twin turbos to the mix

You should have no problem achieving your goals

Bon

[heRS]

I learned something new, that whole long block short block thing has been a mystery to me forever. thanks, guys!

[SSE 4 2SS]

Originally Posted by heRS

I learned something new, that whole long block short block thing has been a mystery to me forever. thanks, guys!

You know what they say about questions...