347 Build Up Advice Needed

[Thomas A]

Well, the time has come. After almost a year of strongly disliking my current motor, I've decided to part it out and build something else for my 1993 Thunderbird. I'm going to need a lot of help and advice though. 90% of what I know about engines and setups relates to the 3.8L SC. So, any advice would be much appreciated! I have found searching the Corral a waste of time. One post will say something is the greatest ever and another will say it's the biggest pile of crap ever, so that isn't going to help me out any.

PLAN:
I'm looking to build an EFI 347 Stroker that will still be fairly streetable. My goal is 400rwhp and 400rwtq. I'm looking at running NA on pump gas at 10.4:1 compression. I guess my theory behind this is to run the best possible heads/cam/intake combo to achieve this goal NA. Do you think that this goal is even reasonable?

BLOCK:
I'm strongly leaning towards the FRPP roller block, 2 bolt main, cast crank, SAE 4130 forged rods, Federal Mogul bearings, and hypereutectic pistons. My only concern is if it going to be strong enough. I don't plan on every spraying it or adding a blower. I really want to keep it NA. The next option would be a DSS block, but that's about $500 more. I don't plan on spinning it much past 6,000rpm. Also, windage tray or stud girdle? Advice on the block??

HEADS:
I think I've got my mind made up here. Looking at the Jegs/Kaase aluminum heads. 7/16" stud mounted rockers, 247cc intake runners, 1.375 exhuast ports, 60cc CNC chambers, 2.10"/1.60" stainless valves. The other possibility is the Trick Flow Twisted Wedge heads. They are about $500 less, but from what I've read and heard, not as good of a head. The heads is one place that I went cheap and screwed up on my current motor, so I don't want to make that mistake again. Advice??

Intakes:
I've been looking at the Trick Flow Tack Heat upper and lower intake with a 75mm TB. The rpm range is 1500-6500 which is right were I am looking to be. I've also kinda been looking at the FRPP GT-40 manifolds. They claim to be the best, but who knows? They are another $150, but I am wondering about how streetable they would be? Not really sure between the two??

Cam:
I have nooo clue on the cam. When I was originally looking at the TFS TW heads, I was just going to go with thier matching cam. Now that I will probably go with the Kaase heads, I'm not sure what kind of cam to run. I totally screwed up on the cam choice on my current motor, so I don't want to repeat that mistake. Again, I think something in the 1500-6500 range and will still idle half way decently. Most likely be looking at 1.6 or 1.7 roller rockers. I really have no idea of what cam I'd like to use, so any advice on lift and duration would be much appreciated!

Fuel:
I'm not really sure of the fuel needs on a NA application. I'm running 42# injectors in my SC right now, but I know that SC vs. NA is totally different. Would 42# be too much for this engine? Would 30# work better? Also, adjustable fuel pressure regulator of stock? I'm currently running a Walbro 255FI pump. Do you think that will be able to keep up with a motor like this?

Other:
I'm planning on running all MSD ignition, high flow oil and water pumps, Griffen radiator, and some coated long tube headers with 2.5" high flow cats going back to a dual in, single out 3" resonator, 3" pipe back, and then Y it into a dual 2.5" Dynomax mandrel bent setup. Probably just some FRPP lifters, timing chaing set, intake pipe, etc. Pro-M MAF for sure, most likely thier 75mm unit. March underdrives and such. Anything else I should for sure consider?

Any advice that can be offered would be much appreciated. Thanks!

Thomas

 

[xYoung347x]

My combo is N/A which put down some power. 378hp/417tq.
347 w/ 9.7 compression
AFR 185 Heads
Compcam XE274HR .224 .232 .555 .565 .112
Edelbrock RPM w/ some port work
73 C&L MAF w/ 30lb injectors
255lph walbro fuel pump
4.10s gear

 

[cobrabuilder]

I don't plan on spinning it much past 6,000rpm. Also, windage tray or stud girdle? Advice on the block??

The 347 I built for a friend was a CHP and believe me, the car pulls and wants to rev past 6000. He uses 30# injectors with a Holley Systemax II intake and old school Dart Iron fully ported heads. We used a stud girdle and the 4340 H-beam rods with forged pistons. His car is a '93 Cobra and we used the factory block with no problems, yet. The cam is a Ed Curtis custom grind. Hope this helps.

 

[RIXX93GT]

Working on my first 200 miles with my new 347. AFR185,FTI combo has been great so far. I went with a stud girdle. I am keeping a close eye on my plugs and so far my 24lb. injectors are keeping up fine. Great throttle response no idle issues. Hasnt seen a dyno or good tune yet.

 

[kystang1889]

D.S.S. has a crate motor 347 long block with 11:5:1 compression i beleive, and AFR 205 heads making 450 hp and either 500 or 550 tq can't remember exactly off the top of my head anyway seems like you got a good plan, i'd go with a custum grind cam and the holly intake

 

[r.barn5.0]

1. I would keep the compression at 10:1, no more
higher compression limits how much timing you can use and
timing makes more power than compression.

2. If you dont ever want to add a blower or nitrous and
keep rpms at 6,000 or less than a stock block will be fine.
a. add a windage tray
b. get valley reinforcers installed, not stud girdle
studd girdles are a waste, thats not where the block is weak

3. Get the Holley Sys II intake, Track Heat is not enough.

4. you will need 36# injectors, 42's would work but might have hard start
problems.

5. Look at Canfield 195's for heads
MAKE SURE YOUR SPRINGS MATCH YOUR CAM

6. Get a custom ground cam, they're good for 20+hp
www.camshaftinnovations.com ( they can put complete head/cam kit together )

400rwhp is doable but eveything will have to be just right.
high 300's for sure.

 

[EMW150]

You're on the right track. But spend the extra few bucks on Forged pistons and forget the hypers. Even though your not going with any power adder, 400 to the wheels is going to be a healthy setup. The additional piston rock, etc you get with a stroker you need good strong pistons. And the stock block will be fine for you.

 

[fastranger347]

400hp at the tires or the crank??