So my wifes truck decided to blow a head gasket. Now im going to "completely" rebuild the engine and plan to twin turbo it afterwards. I really need some help in choosing the less common parts. I am on a fixed budget but i also want to be sure the engine I build is going to hold up to the extra power. I plan on using two T3/T4 turbos and a massive intercooler, complete exhaust, (port and polished head, intake, and exhaust), MSD ingnition. (((((Later im going to change the throttle body and the cams then the heads.)))))
All advice and concerns are more than appreciated.
Help me out guys.

 

I am no expert, but I guess you already know about turbo cams, forged rods and pistons. I would want a forged crank also. I didn't build my motor, but VT Competition Engines did, so I know it has all the right goodies in it. I know you say your on a budget, but there are some things that you can't afford to go without if you want it to stay together and have piece of mind to boot.

 

I really dont think i need a crank and a cam for the strength. The turbos I plan to use are small and I dont think i'll be able to do any damage to the crank with them. I do plan on forged pistons, connecting rods, and wrist pins for the strength though.

 

The cams would be designed to work better with a turbocharged engine. The cams in my motor are stage 2 blower cams for example.

 

Ya I understand that but i just dont have the money right now. I just want to focus on the pistons and connecting rods right now. I may not even hook up the turbos untill i have money for the cams. For now my wife just needs something to drive. I just want to get as much done as possible while I have it out.
Know of any cheap rods and pistons??? I think im gunna end up being .020 over bc of cylinder wear.

 

You think i'll be okay using the stock valvetrain and heads?

 

Your budget doesnt match your goals.

A twin turbo setup will require extensive mods.

Pistons with the right ring set will be close to 1K. Make sure you buy forged pistons made out of 2618 material. Do NOT use Moly, Hellfire, or standard iron rings or it wont last. You want Stainless ringset.

Wrist pins. Do NOT use the standard 4130 wrist pins of either .120 or .155 wall. The .155 wall pins are only good to about 550 give or take. You will want an upgraded tool steel pin that is .155 or .220 wall thickness and they will take the abuse of a TT setup.

Rods, Manley H beams will work just fine just make sure you have ARP 2000 rod bolts. These are in the 600 dollar range.

Crank. If you have a 6 bolt crank then it is NOT forged and is only good to about 500-550 horsepower through a stick in a RWD car. So through an auto it will be less. You should replace the crank with a forged Kellogg crank out of an 03-04 Cobra which runs just short of 1K.

Bearings are very important. In a boosted application the bearings take a shear amount of abuse and these must be for the right block and they should be hardened and coated.

I can go on further but its not that easy and Ive done several modular engines. I can help guide you with your build and even help you get parts or do the assemble myself.

I would not recommend it for a novice to be very blunt. One weak point in the motor and it is very likely to cause extreme motor damage when it fails.

 

Sounds like your just the man to help. Im not a novice to engines themselves but I am to the extras like what size TB, MAF Sensor, fuel injectors, intake manifold, chips, and computer programming. I would really like to use as many of the engine parts that I already have. Im willing to sacrifice performance for peace of mind knowing that im not gunna blow my new engine. If I go with a single turbo and intercooler setup with a low boost setting do you think I could salvage my crank, cams, and heads?

 

If the crank is forged, yes, cams and heads yes you can but it will put out more torque then power and fall on its face up top. A good set of cams isnt that expensive but you will need valve springs and retainers.

TB, MAF, Injectors, manifold, FUEL SYSTEM, etc. Thats a long involved process that isnt cheap nor easy.

But if you build an absolutely solid motor from the start and run it NA until you can do the rest of the mods then its not that hard. Start with a solid foundation and work your way up. Intake manifold can be changed easily as well as several other things.

I do alot of custom fab and engineering products and components and Ive blown up a "Built" motor before so investing wisely in a good engine combo will save you money later down the road. Just ask me how I know.

 

So you say the stock engine is rated for 500-550hp max and a stock 4.6 engine delivers 231hp. That tells me that I can add 169hp and still use stock parts. How much hp do you think one small T3/T4 turbo is really going to add?

 

You might wanna re read what I said. I never said anything about the stock engine. I said the stock crank would take AROUND 500-550rwhp in a manual RWD CAR. That number is alot less through an auto trans and even lower with 4x4.

Just because the crank can take x amount of power doesnt mean the rods wont fail, the rod bolts wont stretch, or the pistons ringland wont fail at that same amount of power.

 

What else is involved in adding a small turbo other than strengthening? I really just need a list of thing s that im going to HAVE to do NOW.

 

Build the motor first then worry about the turbo stuff. Take it in small bits and work out any bugs before moving on to something else.

Ive had my car down to almost nothing and it is very hard to track down problems when you change alot at once.

 

Ok so I need .220 pins, forged pistons and connecting rods, and quality rod bearings and bolts. Whats the cheapest I could do this for. This isn't going to be a mud truck or a race truck. Just an above average daily driver for my wife.

 

Is your crank forged?

New.

New crank $1300
New Pistons with upgraded Pins $900
New pistons ring $260
New Rods $700
New bearings $200-250
Cobra Oil pump $61
Cobra Pickup tube $98

You can find the crank, rods, and pistons used but the prices vary on condition and mileage.

Never reuse a pick up tube or oil pump.