[1970GTOECKLEY]

Hey everyone just finishing up a Pontiac 400 build .030 over forged pistons,stock rods arp bolts,#62 heads new valves,springs etc,mild port work,XE274h cam,Torker 1 intake,Holley 750DP carb,Tri-y headers,HEI dist. Im 18 years old this is my first engine build and its going into my 1970 GTO it will be dynoed at the trade school I go to and im just wondering how much power the engine should make crank/rear wheel. Share your build and dyno numbers also please if it is a similar build.

[Dragncar]

Cool deal kid. First car, 70 GTO. That is something these days.
My first car was a 69 GTO but that was 1982.
I would get up the 250$ for some offshore 5140 units and get rid of the cast rods. Seen too many on 13 and 12 second 400s fail.
The T1 should be replaced. NOOOO bottom end at all on a 400. You get a good pull past 5000RPM but you have to shift by 5800-6000 with cast rods.You are even better off with a 70 iron unit with the right setup. Get a T2 instead. They work very well on mild 400-428s.
You have the right heads for a pump gas 400 with TRW flat tops.

[1970GTOECKLEY]

Already have it pretty much built. hopefully the rods will be fine how much power you thinking it will make and I love a 69 GTO!

[ponyakr]

I realize that the engine is already built. But just for what its worth. From what I've read, the XE 274 cam is too much for a street 400. Most run that cam in a 455+ engine. And the steep ramp cam may help make the 400+.030 with #62 heads have detonation problems with pump gas.

But, I could be wrong. If so, some of the experts will correct me, I'm sure.

I just ran some numbers thru the CR calculator and came up with 9.92 CR. That's assuming 75cc chambers, .039 x 4.3 Fel-Pro head gaskets, and .010 deck. If it's been zero decked, that'll add some. And if the heads have been shaved for less than 75cc, that will add some. And, the XE cam will add some cylinder pressure for more dynamic comp.

http://www.wallaceracing.com/cr_test2.php

I've read that most Pontiac engine builders recommend no more than 9.5 CR for pump gas engines. I know this has been debated many times. But the OP has probably never read these debates. So, some other opinions may be helpful here.

Also, if you have an auto trans, you'll need a stall converter, cause the motor with a Torker intake and a double pumper, will have very little low end torque.

Hey, we're not trying to spoil your party. But we also don't want you to build a motor that you won't like. If it has no low end torque, and has detonation problems with pump gas, you will not be happy with it.

[dmac]

Sounds similar to a 400, .030 over I had years ago. I loved to drive it on the freeways/highways. I think I had a 2.73 rear ratio, and it pulled hard from 50-100 mph. Only downside was having to drive around town in low gear, up to about 30 mph. I once drove from the SF bay area to Reno in 2nd gear, just cruising at 70 mph. I had made homemade snorkels from aluminum dryer vent tubing forcing a lot of air into 12.5:1 compression chambers, 115 octane rating, ice cold air. Stock rods, pistons saw 6000 rpm only a few times. With the 2.73 gear ratio, you don't need a lot of rpm to build up speed, but it takes a little longer.

[P@blo]

Back from the dead...

[rtanner]

Originally Posted by Dragncar

Cool deal kid. First car, 70 GTO. That is something these days.
My first car was a 69 GTO but that was 1982.
I would get up the 250$ for some offshore 5140 units and get rid of the cast rods. Seen too many on 13 and 12 second 400s fail.
The T1 should be replaced. NOOOO bottom end at all on a 400. You get a good pull past 5000RPM but you have to shift by 5800-6000 with cast rods.You are even better off with a 70 iron unit with the right setup. Get a T2 instead. They work very well on mild 400-428s.
You have the right heads for a pump gas 400 with TRW flat tops.

have never seen a stock pontiac rod fail, heard people repeat over and over they will, but 100s of passes tens of thousands of miles, tons of friends w pontiac, nope never seen one, and i started in 1977 w my first 400 fb, so sleep well kid your rods will be fine!!! that chevy cam will suck, but your rods w be fine

[i82much]

Originally Posted by Dragncar

Cool deal kid. First car, 70 GTO. That is something these days.
My first car was a 69 GTO but that was 1982.

I agree, this is as cool as it gets. My first was my 65, that was in 1991. You are talking about a 45 year old car, that is really awesome.

Let me ask you this - how far do you expect to drive every day? You are posting on a forum with a bunch of old guys that care about stuff like not running high rpms all the time, overall driveability, hell we even care about cold starts and all get annoyed with the slightest exhaust leak. We spend hours on forums researching our next oil filter purchase or trying to decide between running 27 or 28 PSI in our tires for our next road trip.

But you are freaking 18 years old! I say to hell with all this, slap some 3.90's or 4.11's in the back and go burn some goddamned rubber, cruise around at 3000 RPM, smack it in the ass every time you go around a corner. Break every last damned drivetrain part on the car and learn how to put it back together in your sleep. That's what we all did at your age.

20 years from now, you can log in and we can have a nice 37 page thread about PCV valve calibration or hydraulic lifter bleed-down rates. Right now, kid, you've got rubber to burn and hearts to break. So get to work

[PunchT37]

Originally Posted by i82much

But you are freaking 18 years old! I say to hell with all this, slap some 3.90's or 4.11's in the back and go burn some goddamned rubber, cruise around at 3000 RPM, smack it in the ass every time you go around a corner. Break every last damned drivetrain part on the car and learn how to put it back together in your sleep. That's what we all did at your age.

20 years from now, you can log in and we can have a nice 37 page thread about PCV valve calibration or hydraulic lifter bleed-down rates. Right now, kid, you've got rubber to burn and hearts to break. So get to work

LOL.

[PunchT37]

We ran a T1 on a 350 back in the day. We didn`t know better, or gave a sh!t. We turned it 7 grand with 3.90 gears. Lasted a good while before a couple of the cast pistons broke. Go figure. Pistons, not the rods.

Back to yours, run it as is or get a RPM manifold or at least a T2. Keep the Holley. That T1 does suck, especially on the "smaller" engines.

Just because we were dumb doesn`t mean...

[69goatboy]

Originally Posted by i82much

I agree, this is as cool as it gets. My first was my 65, that was in 1991. You are talking about a 45 year old car, that is really awesome.

Let me ask you this - how far do you expect to drive every day? You are posting on a forum with a bunch of old guys that care about stuff like not running high rpms all the time, overall driveability, hell we even care about cold starts and all get annoyed with the slightest exhaust leak. We spend hours on forums researching our next oil filter purchase or trying to decide between running 27 or 28 PSI in our tires for our next road trip.

But you are freaking 18 years old! I say to hell with all this, slap some 3.90's or 4.11's in the back and go burn some goddamned rubber, cruise around at 3000 RPM, smack it in the ass every time you go around a corner. Break every last damned drivetrain part on the car and learn how to put it back together in your sleep. That's what we all did at your age.

20 years from now, you can log in and we can have a nice 37 page thread about PCV valve calibration or hydraulic lifter bleed-down rates. Right now, kid, you've got rubber to burn and hearts to break. So get to work

You sir, have just won the internet.

[1970GTOECKLEY]

Thanks everyone for the reply!

[Squidward]

Originally Posted by 69goatboy

You sir, have just won the internet.

Without a doubt!

Favorite part? "Right now, kid, you've got rubber to burn and hearts to break. So get to work"

Sig worthy!

[Jayptn]

I’m new to the Pontiac scene but not cars. I wish somebody would have said this to me 20+ years ago. I agree. Racing gas,4.11s, 3200 stall and LET IT GO!!!!!!!! Don’t spend forever NOT driving for the sake of ONLY driving a finished product. That killed my drive to drive when it went bad.

Originally Posted by i82much

I agree, this is as cool as it gets. My first was my 65, that was in 1991. You are talking about a 45 year old car, that is really awesome.

Let me ask you this - how far do you expect to drive every day? You are posting on a forum with a bunch of old guys that care about stuff like not running high rpms all the time, overall driveability, hell we even care about cold starts and all get annoyed with the slightest exhaust leak. We spend hours on forums researching our next oil filter purchase or trying to decide between running 27 or 28 PSI in our tires for our next road trip.

But you are freaking 18 years old! I say to hell with all this, slap some 3.90's or 4.11's in the back and go burn some goddamned rubber, cruise around at 3000 RPM, smack it in the ass every time you go around a corner. Break every last damned drivetrain part on the car and learn how to put it back together in your sleep. That's what we all did at your age.

20 years from now, you can log in and we can have a nice 37 page thread about PCV valve calibration or hydraulic lifter bleed-down rates. Right now, kid, you've got rubber to burn and hearts to break. So get to work

[Jayptn]

To reinforce: Make your largest life expenditure at that age gas and tires!!!! Be THAT GUY!!! The everybody hates because he always drives around with the headers uncorked!!!! Put a cheap paint job and late model yard interior and chase down females!!!! You will NOT REGRET THIS!!! Ask the guy who I’m posting this on.

Originally Posted by i82much

I agree, this is as cool as it gets. My first was my 65, that was in 1991. You are talking about a 45 year old car, that is really awesome.

Let me ask you this - how far do you expect to drive every day? You are posting on a forum with a bunch of old guys that care about stuff like not running high rpms all the time, overall driveability, hell we even care about cold starts and all get annoyed with the slightest exhaust leak. We spend hours on forums researching our next oil filter purchase or trying to decide between running 27 or 28 PSI in our tires for our next road trip.

But you are freaking 18 years old! I say to hell with all this, slap some 3.90's or 4.11's in the back and go burn some goddamned rubber, cruise around at 3000 RPM, smack it in the ass every time you go around a corner. Break every last damned drivetrain part on the car and learn how to put it back together in your sleep. That's what we all did at your age.

20 years from now, you can log in and we can have a nice 37 page thread about PCV valve calibration or hydraulic lifter bleed-down rates. Right now, kid, you've got rubber to burn and hearts to break. So get to work

[4mula73]

I'm building a 400 that's pretty similar to yours. My cam is a tad smaller than the XE274, and I mean just a couple degrees of duration and about .030" of lift. I'm using 6X-4 heads with mild portwork, 9.44 compression, Performer intake, quadrajet, and Hooker 1.75" headers. I built mine wanting to be close to 400hp at the crank. All in all, very close to your build. I'm 18 too! Mines going in a 73 Formula 400. I'll be getting it dynoed sometime around May or June. We'll have to keep in touch and see what our builds made!

[screamingchief]

Originally Posted by 1970GTOECKLEY

im just wondering how much power the engine should make crank/rear wheel.

I'd say around 350-375 @ the crank,+/- say a 10 hp "fudge factor" either way.
And maybe 275-290 @ the wheels,that depends on drivetrain losses though.

JMWAG

No armchair quaterbacking from me,I'll leave that to the others.

Good luck with it,and enjoy the experience,just dont let any $h!t get to you,we've all BTDT,it's just part & parcel to the automotive hobby.

Bret P.

[steve25]

If your 70 is a auto and does not have at lest 3.73 rear gears than the T1 manifold will not have the low speed power your likely thinking your gonna have to peel rubber!
Your really going to want to search out a at least a use Edelbrock PB duel plane square bore carb manifold , or a performer rpm that will accept that Holley carb.
Does the Dyno at your school have sensors to track ping and knock as you may have some of that to deal with andthe way to go if you can make enough pulls would be to run 32 degrees of timing on up to 40 to see what the motor wants!
In stock form with those heads thise motors where between 325 and 350 hp and if you can spend enough tuning time on the dyno you should have 375 to 380 hp on tap.
Oh, I would advance that cam 4 degrees also as 2 degrees of it will make up for normal timing chain stretch at revs above 4500 and or once the motor gets 15K miles on it!

[meanone]

I'm with switching the intake to a '67-'70 cast iron stocker and put some 3.90-4.10 gears in there. I think that you'll be real happy with it. Call PTC and get a good stall converter, probably around 2,500-3,000rpm. Should be pretty quick. I would guess 380-390hp also, maybe 400.

[74Grandville]

what rear gears? As others have stated, I think 3.73s are needed to match your setup. here is what DD2000 is showing for me.