Twin Turbo Small Block Build

[acamacho104]

Hey guys, I'm looking for some advice on a build I want to do.

I've never built an engine from the ground up before, but I'm confident that if I take my time and get help from more experienced people I will be fine.

The idea is to build a 650-700 hp twin turbo small block chevy. I'll likely start with a 4 bolt 350, but I may make the bump to a 400 (Just concerned about engine temps because 400 blocks tend to get a little hot). I'm okay with using race gas, although I'd like to be able to drive the car to shows at some point wwhen it's finished.

I have done a little bit of research and know some of the things I need to make it happen, but being inexperienced I'm not 100% positive.

I'm not made of money so I can't get too insane with this build. I'll probably start with a stock cast iron block. I need a better idea of what bottom end (obviously forged), cam, and heads to use.

From my research I've been thinking to keep the cam mild (what exactly mild is idk). Also use dished pistons and try to get a 8:1 compression. I have no idea what brands are good and any other crank/rod specs. Heads are the biggest confusion for me. I heard vortec heads might be good for the application, so i dont have to blow too much money on aluminum race heads.

Again not made of money. Any help would be greatly appreciated.

 

[acamacho104]

I would also like to say I want to have some level of reliability. I don't wanna cut corners where it will cost me big money or big headaches later.

 

[ahtoxa]

You surely aren't talking about fitting that into a Sonic, are you?

 

[acamacho104]

Definitely not. Thats why its in the off topic section. I want to get a mid 80s caprice and do it to that. It was my first car and i had big dreams that never turned into anything. Now i think i could treat her right. They're big old boats, but they have tons of room under the hood and nobody would expect it

 

[Sneakerfix]

Your best chance is a 5.3 or a LQ engine stronger build

 

[5.0]

Trying to do a twin turbo 700hp build without a lot of coin is going to be tough. You didn't say what your budget is.

You could use a LQ4, LQ9 6.0L chevy to start if you want an iron block.

Or you could order a LSx block.

Personally if you're trying to do it for cheap, you can find used low mileage LS7 for around $6000. Add heads and cam and your over 600hp at the flywheel all day long. And who doesn't want a 427 small block in their car.

 

[acamacho104]

I have as much coin as it will take, just not all at once. And I dont want to just throw money and parts at it. Because then i might as well just buy a crate motor. I'm looking for something to work on a little at a time.

I'm determined to do it. It just might take a while. I don't have a set budget because its really something that i want to work on a little at a time as I have extra money. So, I want to be smart about how it's spent.

So, pulling $6k out of my pocket at a time isn't exactly what I have in mind.

 

[rdss]

The LQ4/9 would be a good option, it is a solid motor and you can add to it as you go.

 

[Scot]

LQ4, stock internals are good for 8 to 9 lb of boost / 800 hp. The 9.4:1 CR and cast iron block ( not to mention the superior "girdle" method of bolting in the crank) are a big fave of guys around here.

 

[CheapFuneral]

Yeah go with a newer truck motor for sure. Cast iron 6 bolt mains . I also like the ls7 idea, but turbos are fun. Ls7 turbo? don't go with an older block the newer ones can be had so cheap and they are so much better.


**** you auto correct!

 

[Dirkdaddy]

With that engine you could... later after you quit driving that boat around fit it in a variety of cars/trucks and not lose your investment. I love turbo engines for streetability and sleeper-ness, plus reasonable fuel milage when not boosting.

A S10 would be a fun truck to run it in...

 

[acamacho104]

I really wanted to go carbed, because I'm not looking forward to running wires and tuning on a computer and all tha5goes with injected engines, but it appears as though nobody else is thinking that.

 

[Sneakerfix]

I really wanted to go carbed, because I'm not looking forward to running wires and tuning on a computer and all tha5goes with injected engines, but it appears as though nobody else is thinking that.

Tuning carbs for boost is more work then needed and at times cost more. Running a few wires is cake for an LS based swap with all the harness kits out now.. A stock LQ can make close to your power goal on stock pistons and a single turbo swap.

You can also convert to carb on a LS/LQ engine

 

[acamacho104]

I see. It's just the whole fi thing is unknown to me. Thats a whole new world and I know even less about it than I do carbs.

As far as i understand i just need a blow through carb and an msd box set up to adjust timing for boost.

I wouldnt dream of trying to fit a standard carb on a boosted application. Thats a boatload of work. The blow through carbs are designed to increase fuel flow as they see boost.

Of course I'm just trying to do my research right now.

 

[acamacho104]

I also have to think about the availability and cost of the transmission that needs to be fitted to this thing.

If i use an ls/lq i have to use a trans that fits with it but make that work in a vehicle that wasnt designed for it.

Again just trying to sort out some research.

 

[Sneakerfix]

I also have to think about the availability and cost of the transmission that needs to be fitted to this thing.

If i use an ls/lq i have to use a trans that fits with it but make that work in a vehicle that wasnt designed for it.

Again just trying to sort out some research.

If your going 6speed a T56

Auto power glide 700r4 and so on they all fit.


I have M30 with a LM7 swap Building

 

[acamacho104]

The 700r is compatible with a lq? I dodnt know that

 

[Sneakerfix]

The 700r is compatible with a lq? I dodnt know that

I only put out the 700r cause you wanted a carb set up. My choice would be a 700 with 4L65E internals..


My M30 has a T56.

 

[acamacho104]

I've got some thinking to do. Thank you.

 

[jgrote]

Having been down both roads, I strongly recommend going FI. With the systems that are out there now, it is sooo easy. For driveability, you will appreciate it in the long run. There is a reason why everything from lawnmowers to boats to bikes to cars are FI now. I will have to say though, plan on having it professionally tuned after you build it. Whether you go with carb or FI, you should find a reputable tuner that you can trust. As for choosing ANY electronic control system, talk to your tuner before you buy anything. They will be able to tell you what they have seen work, what systems they are competent in tuning, and what they feel is junk. Any tuner worth their salt should be willing to have this conversation with you at no charge.