building a motor for boost, need some opinions

[02gtfromky]

im building a motor for boost for my eaton swap, this will be my first mod motor build. im going to use my block and crank (mach 8 bolt) and keep stock bore to save machine work and $$. what is a good piston and rod set up that will allow me to keep around the same compression as i have now. im not wanting to lower my compression none.

also, what is a good heads and cams set up? i was told to grab some B heads and have them worked over? cam wise? 98 cobra intake and 03 cobra exhaust? or both 03? im lookin to get the best bang for the buck without aftermarket cams and springs. im going to be doing this on budget.

the most this motor will see is 650 rwhp but i want to be able to beat the snot out of it. my tuner is awesome so i know the tune will be right, im concerned about the parts lol

[Chances50]

Mod max rods, and Diamond pistons, DO NOT buy B heads your stock heads are a better head and you would have to change way to much to run them. you can have your stock heads ported if you like but its not needed to make the power you're after.

the 96-01 intake cams are a nice upgrade, the 03/04 Mach's and Cobras have the same intake and exhaust cams.

IMO i would do forged pistons and rods, head studs, full exhaust and call it good with the right amount of boost 650rwhp is easily made.

you are only going to pick up 10-15rwhp from cobra cams on a boosted car i wouldnt waste the $150 on them. im thinking about selling mine when i do new head gaskets and sticking my stock cams back in.

[lxh89]

Originally Posted by 02gtfromky

im building a motor for boost for my eaton swap, this will be my first mod motor build. im going to use my block and crank (mach 8 bolt) and keep stock bore to save machine work and $$. what is a good piston and rod set up that will allow me to keep around the same compression as i have now. im not wanting to lower my compression none.

also, what is a good heads and cams set up? i was told to grab some B heads and have them worked over? cam wise? 98 cobra intake and 03 cobra exhaust? or both 03? im lookin to get the best bang for the buck without aftermarket cams and springs. im going to be doing this on budget.

the most this motor will see is 650 rwhp but i want to be able to beat the snot out of it. my tuner is awesome so i know the tune will be right, im concerned about the parts lol

JE Pistons: http://www.jepistons.com/Products/257540.aspx

Eagle H-Beams: CRS5933F3D

ARP 2000 Rod Bolts

Rods and Pistons will handle 1000BHP and the price isn't too bad. If you want 650rwhp and want to beat on it, you want some headroom.

Tony

[birdman941]

With a PD blower, you should lower the CR 1 to 1.5 points.
With a centri you can leave it the same, unless you are planning no high boost.
Also, I agree with the above post, B heads are crap, keep what you have,
get them ported.
You need to retorque head studs after a heat cycle or 2.
Not fun on a Mach 1.

[DSG2003Mach1]

Originally Posted by birdman941

With a PD blower, you should lower the CR 1 to 1.5 points.
With a centri you can leave it the same, unless you are planning no high boost.
Also, I agree with the above post, B heads are crap, keep what you have,
get them ported.
You need to retorque head studs after a heat cycle or 2.
Not fun on a Mach 1.

but using stock head bolts doesnt require retorquing right?

[02gtfromky]

my actual plans for the car will either be a posi ported eaton or a posi ported gt500 blower. with a 2.76 and MAYBE a 4# lower, but that is the max boost itll see. i dont wanna lower my compression from where i am now unless i absolutely have to. itll have arp rod bolts and head studs, just for a peace of mind. unless i can get by with head bolts so i dont have to retourqe em lol

as of right now, the car has long tubes and 8# of boost the car made 483/445 at 6200.

as for oil pump, what do yall recommend?

also will my crank and block hold 650ish safely?

[NastyNate]

Diamond or Manley pistons
manley hbeams

keep your heads the bhead will cost too much to get to where they need. our heads are better
I agree to drop the c/r


Block n crank are good for more than 650

[birdman941]

Originally Posted by DSG2003Mach1

but using stock head bolts doesnt require retorquing right?

No they do not
Oil pump: Melling 10227 billet HV pump

[02gtfromky]

What c/r are y'all recommending when you say drop it? What is the compression on these motors currently?

Will stock head bolts be enough for my build?

[lxh89]

I've seen published numbers of 10.1:1 to 10.3:1 for stock mach 1. The engine on my car is 8.65:1 (17cc dish pistons) but I'm running a PD Blower (whipple). For a centrifugal/turbo, you can get away with more compression since those setups tend to build boost in higher rpms whereas a PD blower generates boost at a much lower rpm (exception being a twin turbo setup with small turbos).

If you are building a race car and plan to run race gas, E85, E98 or methanol, you can get away with a much higher compression ratio but the operating assumption is this a street driven car that will be raced periodically. If you have easy access to E85, running 10:1 compression and PD blower is within reason, but if you only have 93 pump, you'll find the amount of boost you can run will be significantly lower than someone with lower compression. Furthermore, they will likely produce more power on 93 pump. However, your car will get better gas mileage and have snappier part-throttle response with the higher compression.

Tony

[02gtfromky]

it will b a street driven car, weekend warrior pretty much. ill only have access to 93 around these parts.

im going to keep my heads, prob throw in some 98 cobra intake cams and roll with it. like i said id like to stay within my compression as i have now. i like that fact that im making the same amount of power stock, as a pullied 03/04 cobra!

[Mach828]

Lowering your compression with a stock or ported eaton would be a big mistake. Only reason you'd want to lower it would be if you had a 3.4L whipple on it running 26#s with 93 octane gas.

The route your planning sounds good. Port that eaton, clean up the heads, cobra cams, pulley it, and you'll make great power.

[02gtfromky]

im really excited to what she makes with a ported m122!

stockish compression, 2.76 with a 4# lower should put me around 600-620 with crazy TQ

[birdman941]

And forget about the 98 Cobra cams.
Waste of money for virtually no gain.

[Chances50]

I wouldn't lower the compression. Keep it as it is. A guy I know just built up his 03 Cobra went with 10.7 compression, ported eaton on 19lbs and e85 made 580rwhp 618rwtq.

Yes by lowering the compression you can run more boost, but with higher compression you won't need to run as much boost to make the same power.

[Mach828]

Originally Posted by Chances50

I wouldn't lower the compression. Keep it as it is. A guy I know just built up his 03 Cobra went with 10.7 compression, ported eaton on 19lbs and e85 made 580rwhp 618rwtq.

Yes by lowering the compression you can run more boost, but with higher compression you won't need to run as much boost to make the same power.

That would be a fun setup to drive on the street!

[helomech74]

You don't need to retorque head studs after install. I have over 500 1/8 and 1/4 mile passes on my drag car and it's never been opened up after I built it. My street car has about 6500 miles on it after it was built, also never opened up.

Don't lower your compression at all. If you want to run off the shelf pistons, I would go with JE pistons personally. If you want to spend a little more for custom pistons, I would go with Manley or JE Customs. I'm partial to Manley personally especially when it comes to custom pistons. Any 4340 H beam out there will work for you, Eagle, Probe etc, but I would still spend a little more run Manley's or find some take out 03/04 Cobra rods (Manley pieces.) Swap in ARP2000 rod bolts (will require machine work on the rods to do this), keep your crank, I'm partial to King or ACL coated bearings, but you can run whatever. I'm also partial to Total Seal AP rings with Stainless top and Napier cut 2nd. Don't worry about swapping in different cams with what you want to do, I would still swap valve springs since you are tossing some boost on top and possibly some more RPM, but not a requirement. B heads don't "Suck" as folks in here have said, but they aren't native to your engine and you won't gain anything from changing.

Sounds like you are going to have a nice runner for sure. Build it yourself if you can and enjoy the process. No one cares more about your engine and the money you spent on parts then you do.

[vertigyn]

Subing for when the time comes to build my engine with my 2.1 KB