Engine 347 Build Thoughts

pete_05_gt

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Feb 23, 2014
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Hey guys want some feed back on this build. So the plan is around 1000 hp. here goes : CHP dart block 347 short block, AFR 205 renegade heads, Trick Flow box R intake, Accufab 90mm throttle body and 90mm mass air, SFI approved damper and flexplate, Vortech YSI trim. Still working on some details such as cam, pushrods, rocker arms and fuel system. I plan on putting a built TKO 600 behind it with a 9" rear end. Any thoughts feed back or suggestions would be greatly appreciated. Thank you. The most important part it's going in a 1990 GT.
 
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Sounds like a $25k build. I would go with bigger heads and find something stronger than a regular tko600. I'm sure you are fixing to get slammed with the usual "what do you need a 1000hp for" comments.

Joe
 
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The car will have a full complement of maximum motorsports suspension and cage. It will be expensive but I'm building it over time just trying to put the build list together. Another thing I do not want to break into the 9 second 1/4 mile bracket though a 10 flat would be fine lol to much to do in the 9's. So bigger heads and TB I'll start looking.
 
AFR 220 Renegade heads will support that kind of HP in a boosted application with no problems. Usually that kind of HP requires higher RPM's. So you should consider the Jesel shaft mount roller rockers as part of the build. Along with that comes the solid roller camshaft. And you are going to need at least the Kooks headers with the 2" primary tubes and a 3 1/2" collector and exhaust piping. You will also need at least a 160 lb/hr fuel injector (which I happen to have a set of new Precision Turbo injectors for sale) and the Aeromotive Eliminator fuel pump, along with a minimum of a -10AN feed line. Plus lots of other stuff, like say a FAST XFI engine management system.
 
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205's would get you close but like previously stated 220's would be preferable. You definetly will need to spin it hard to get 1000. But you stated 10:00 ET goal. You don't need 1000 hp to run that number. 650-700 rwhp will easily get you there with a good chassis/suspension/tire/ etc. That number can be reached with what you previously stated. A 90mm tb/TFS r box,Vortech ysi,205 head can make 700 rwhp easily. You wouldn't need 160#inj either. More along the lines of an 80# would work. For a trans look into a liberty gear modified tko. You also don't need a 9" rearend. A properly build 8.8 will support those goals. I've actually seen n/a 347's in the mid to low 10's so a boosted one(especially a YSi) is more than capable of a 10.00(more likely a 9.00 if done properly) my question is do you want the ET times or the bragging rights to a dyno number?
 
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Here goes my .02 cents, take it of leave it:

347 is the total wrong approach to try and make that kind of horse power. Look at doing a 363, 4.125 bore will unshroud the valves and make considerably more power than a standard 4" bore. What crank, rods and pistons are you going to use? How much compression? Hyd. roller or solid roller cam? These have a lot to do with deciding on the heads. Do you want to make 1000 fly wheel hp or rwhp because that is a world of difference. Make decisions like this before you even think about deciding on intake manifold and throttle body sizes. Injectors and fuel system components can be a thought after all of this. Are you considering a stand alone fuel injection system? Twin disk clutch at this power level I'm assuming? Is the TKO even going to live behind that much hp? What type of chassis work will you be doing? bolt in parts at this HP level don't exactly jive, sure control arms and stuff will bolt up but what are you doing about torque boxes? Cage? Subframe connectors, and I'm talking about legit through the floor type connectors, not some weld to the bottom of you floor and think it's good type deal. The rear, you don't need a 9" or the hassle associated with making it work with your stock suspension (been there done that) after all that time and effort, you want to make 8 second hp and only go 10.0's?

Personally before you go jumping into this 40,000$ mess plan this out to the T carefully and don't just start throwing your money around. This is a big undertaking, bigger than most people realize. Ask me how I know...
 
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Here goes my .02 cents, take it of leave it:

347 is the total wrong approach to try and make that kind of horse power. Look at doing a 363, 4.125 bore will unshroud the valves and make considerably more power than a standard 4" bore. What crank, rods and pistons are you going to use? How much compression? Hyd. roller or solid roller cam? These have a lot to do with deciding on the heads. Do you want to make 1000 fly wheel hp or rwhp because that is a world of difference. Make decisions like this before you even think about deciding on intake manifold and throttle body sizes. Injectors and fuel system components can be a thought after all of this. Are you considering a stand alone fuel injection system? Twin disk clutch at this power level I'm assuming? Is the TKO even going to live behind that much hp? What type of chassis work will you be doing? bolt in parts at this HP level don't exactly jive, sure control arms and stuff will bolt up but what are you doing about torque boxes? Cage? Subframe connectors, and I'm talking about legit through the floor type connectors, not some weld to the bottom of you floor and think it's good type deal. The rear, you don't need a 9" or the hassle associated with making it work with your stock suspension (been there done that) after all that time and effort, you want to make 8 second hp and only go 10.0's?

Personally before you go jumping into this 40,000$ mess plan this out to the T carefully and don't just start throwing your money around. This is a big undertaking, bigger than most people realize. Ask me how I know...


I think we are looking at another " want to blow 4 years and $40,000" thread coming, Paging @RacEoHolic330
 
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. You wouldn't need 160#inj either. More along the lines of an 80# would work.
Based on my experience in supercharging a SBF, at around 1,000 RWHP you are maxing out a 160 lb/hr fuel injector. We were at 100% duty cycle only 3 seconds into the run. It is better to have it and not need it, than need it and not have it.
EDIT: my bad, with a 120 lb/hr injector we were maxed out. The 80 lb/hr inj. was good for about 700whp. We ended up using a 160 lb/hr injector to get enough fuel to the engine.
 
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Based on my experience in supercharging a SBF, at around 1,000 RWHP you are maxing out a 160 lb/hr fuel injector. We were at 100% duty cycle only 3 seconds into the run. It is better to have it and not need it, than need it and not have it.
EDIT: my bad, with a 120 lb/hr injector we were maxed out. The 80 lb/hr inj. was good for about 700whp. We ended up using a 160 lb/hr injector to get enough fuel to the engine.
Yeah my injector advise was based on the 700 hp number not the 1000 he initially was asking about.
 
Not a dream this project is happening. The reason I asked for advise is to save time and money. The reason I say 1000 hp is to able to take power out of it to keep it from blowing up as easily. I Do appreciate all the help and the knowledge will be put to good use. Low 10s is my goal don't want to deal with nhra comp license and all that mess. So a safe low 10 build is the end factor I'm looking to achieve.
 
You can get to 347 by using a 4.125 bore with the stroke of the 331..........................
I certainly understand this, just don't know why you wouldn't want the extra cubic inches? It's not like the rod angle is so extreme at the bottom of the throw to worry about side loads in the cylinder skirts. The extra displacement is worth it to me, there is really minimal cost difference involved between the two.

It's been my experience that 160 lb injectors are good to 1000rwhp in a blower application. We made 1163rwhp and were 100% duty cycle with them. Switched to a 235lb and made 1327rwhp with no other changes. (just able to properly control the fuel flow)

@pete_05_gt If you want to only go low 10's why not strap on a TFS top end and an Si? This alone will make 500rwhp and if you can drive it propel you well into the 10 second zone. Excuse me if I'm out of line here be there seems to be this stigma that in order to have a b itchin' street car you need to make 4 digit hp.. That is not the case, a properly setup car that makes 500-600 rwhp is a hell of a ride for a street car. If you're looking for wow factor there are plenty of places to spend thousands of dollars other than on a killer motor combo. If you insist on making north of 500rwhp then the dart block is warranted, I would prefer to see 4.125 bore motor and a TFS R or HighPort cylinder head (personal preference) and the YSi will make killer power. Think about driveability in this equation too. Do you need vacuum to operate your brakes? Will you be retaining the P/S and A/C? Cam choice is not easy in a situation like this either.

I just want to know that you fully understand the undertaking that is involved in building a car to this level. @RacEoHolic330 @madmike1157 @Bullitt347 and myself can all attest to the trials and tribulations not to mention the expense of building something totally radical!
 
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While i'm a big Maximum motorsports fan, you probably aren't going to find too many if any cars at the track running low 10's on their suspension parts. I know they say you can use the torque arm and pahard bar at the strip, and you can, but for sure the car will go much quicker with a real drag racing suspension.

I also agree with 84top, it does not take 1000hp to meet your goal. I've seen it done with less than half that.
 
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This is gonna sound all smart ass, but I never really understod the quest for the "big numbered" HP level on a street car. It is completely understandable on a drag car, as speed or ET is only attainable based on overcoming the weight by adding power.

But on a street car it's ludicrous.

How many guys that have 600-700-800 WHP will ever see the benefit of having "that much power" if the car is relegated to living it's life driving to the cruise-in's, and getting groceries?

A 500 WHP fox is an insane ride in of itself, given the relatively short wheel base and sub-3000 lb curb weight, That power level completely sustainable on a Dart based build for like until the 12th of never. Anything north of that is what?............that much extra tire smoke?

** Disclaimer..... IMHO
 
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Ok for 84 and 2000 I like the 600rwhp idea because of the cost factor. What suspension would you recomend? I have built a 642 hp single turbo 408 but I really want to stay on the 302 platform. Believe me guys l am open to suggestions. Mad Mike this will not be a cruiser or grocery getter my 05 does that lol
 
Ok for 84 and 2000 I like the 600rwhp idea because of the cost factor. What suspension would you recomend? I have built a 642 hp single turbo 408 but I really want to stay on the 302 platform. Believe me guys l am open to suggestions. Mad Mike this will not be a cruiser or grocery getter my 05 does that lol
I would talk to @Sharad for all of your suspension needs. He is our resident UPR guru and can certianly set you in the right direction. My car uses 100% UPR prducts suspension and hooks in a dirt parking lot (no really it does) I street drive my car and kill it at the track and their parts are just simply the best!

As far as staying 302 based, that is no big deal. If you are set on a dart block build then look into the big bore builds, the costs are relatively the same and the power potential is much higher! If you don't have a blower for the combo, or when you get to the point where you start looking for one hit me up. I do my best to give members here the best pricing around on any Vortech/Paxton products from pullies to complete kits.
 
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On my 85 I made 442 rwhp on a n/a 347 motor and ran 10.26 @ 127

Specs were as follows:
11.5 to 1 J&E pistons ,
Eagle crank, .
675 solid roller lifer cam
TFS high ports,
ported victor jr
BG Cold Claw,
Holley Blue pump with 8-an braided lines,
ARP main & stud & rocker girdles,
MSD Ignition
1 3/4 l hooker long tubes
X pipe,
tko 5 spd
31 spline auburn pro w/4.56 gears,
subs
Wild ride torque box reinforcements
adj upper and lowers,
Eibach Drag pack,
6 pt cage,
Weld draglites -skinnies up front and 15x10 with MT 28X10.5's,
2600lbs
 
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The stock type rear suspension works awesome for a drag race application. I used all Wolfe Racecraft components. Mustang Products - Wolfe Race Craft Others have used Team Z with success .REAR SUSPENSION
Anyway, the stock configuration works so well, that the Fox Body platform is the choice is small tire racing, even for the Chevy guys. They swap in Chevy power into a Fox platform cause it is cheaper and easier to go fast using it compared to a GM F body car.
Edit: Forgot about the UPR stuff.........derp
 
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You could probably meet your goal of 600rwhp with a 347 or 363 with a T trim. Probably still going to be excessively fast on the street.
Be much more manageable and probably cut the budget in half.
You won't need a 9 inch rear either, just a really well built 8.8.

As for suspension to run the quarter that fast, these guys will know better than me, i'm more of a handling street driving type of guy. I only lasted a few weeks with a drag style setup. I did not enjoy the light front end feeling of the drag setup, in NJ we have jug handles, a lot of them, just the blip of the throttle felt let it took all the weight off the nose and gave me the feeling the car was going to push all the time.

I see you built a big hp engine before, was that in a foxbody? Remember the fox is a car that can run 11's with 300rwhp. So it is a handful at 600rwhp and insane at 1000rwhp.
 
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