drumpro80

ok, so my other thread ran out of juice kinda. But, this is a little different question. I think I have my build lined out. I was thinking of going with a stroker and a blower then possibly running a t56. I have a couple of questions. Number one, since I've never built a complete motor myself, and won't have the money to rebuild it right away if I screw up....should I try it myself or possibly buy a short block such as the ones in mm&ff like the D.S.S. bullitt short blocks? Number two if I do it myself, is it true since I'd probably use a stock block, that I have to do more machine work to run the 347? My goal after adding the blower is also to hopefully make around 500 rwhp....is this REMOTELY possible? Maybe more? Thanks guys!

MustangBradley

500 rwhp is possible with a 347. It is all about the checkbook. But you must rob Peter to pay Paul so to speak. 500 is at the upper range limit so you are sacrificing longevity for power. It is not cool to be stranded on the side of the road with a rod sticking out of the side of your 500hp motor. You are building this for the street, right?

302army187

you can pay a shop for the block work, you can build it yourself, its really not that hard.

347 with mild heads, and low boost will make 500rwhp. but stock blocks dont last long at that level without a super modest tune most people find out.

for all the work you are planing, If it where me. I would just go with a 351w, or a aftermarket block if your set on 302-347 cubic inch's.

and like its been said, anything can be done, its a matter of how deep your pockets are

Tony71502

Machine work for a 347? NO.

A 347 is just longer connecting rods/different crank shaft. If you decide 347 make sure you get the ones with the proper design so the wrist pins get oiled enough. Otherwise you prob blow your engine and complain it is the 347's problem and not the connecting rod/piston head problem. 347 strokers have a bad rep because of dumbasses installing poorly designed rotating assemblies.

Bubba 95SN

Blower, heard boost goes better with 332 and less machine work. Clearance for rods at bottom of cylinder sleeve.

drumpro80

yeah it's for the street. If I were to go with either but wanted to do a better block what's the best for the buck? I have roughly 5-6k for the motor minus the blower. But, that is also going to have to buy h/c/i and EVERYTHING else. Some of the pre man'd short blocks from d.s.s. and other company's were like 2400 with a "race prepped block. That's why I asked about them. Any other input guys? Thanks

Venomantidote95

let me sum this up for you since i just built one of each, this is the list of have to machine work, and some different ways you can get your cu in, first machine work will be bore the cylinders they both require a 4.030 bore (normally) there will be some variances to what i am telling you, Depending on rod brand and bolt or stud size you will have to clearance the cylinder skirts so the rods dont hit the cylinder, and your normal cleaning freeze plug and screwin oil passage plugs, cam bearing install, and please dont be one who puts a rotating assembly together unbalanced, this means pistons weigh the same rods weight the same and your parts have been on a computer dynamic balancing machine, your machine work alone will be between 600-1500$ depending on where you live and what the shop charges

note: the only thing in the above list that wouldn`t be included in a simple overhaul of a 302, 306, 308, 310 cu in engine would be the cylinder skirt clearance.

there are different combonatins to building a 331 and 347 that will either cause some small oil consumtion or some sacrifice on rpm the DSS kits are put together using a 5.315 in compared to your normal 5.4 in rod one pro and one con for each

5.315 will be shorter and will have a taller piston with wrist pin not so far into the bottom ring land also will have a shorter dwell time at tdc and bdc and dont require a spacer ring under the oil control rings.

5.4 rods have a shorter piston and have a longer dwell time for the piston, and the wrist pin will be higher into the bottom ring land and uses a spacer and will sometimes use a little oil.

If you are wondering how to get your cu in here is a simple formula to get it:
bore X bore X stroke X number of cylinders X .7854

example:
4.030 X 4.030 X 3.4 X 8 X .7854= 346.952
4.030 X 4.030 X 3.25 X 8 X .7854= 331.65
4.000 X 4.000 X 3 X 8 X .7854= 301.6

You can spend as little on a 331 or 347 as 8-900$ or up to 15-2000$ on just parts no machine work.

as for the stock blocks use a main support and you`ll be ok but making over 500hp or even close is still iffy, balancing will extend the life of your parts, your block and give you some horses over someone who dosent balance theres!

If i have missed anything you have a question on please pm me i may be able to help.

I have 2 small children running around and i may have lost my thoughts so just give me a shout if i can further help you.

Making 450-500hp isnt hard with either engine depending on heads cam etc, especially with a blower or nitrous, just remember that worn saying how deep are your pockets!

sn95_331_GT_ yellow

you have to notch the bottom of the cylinders with H beam rods on a 331...

and the only thing a 331 has over a 347 is a better rod/stroke ratio that makes it SLIGHTLY more stable at higher rpms.

the piston pin in the oil ring problem is LONG gone now with 347's.

and rpm + a blower is a HORRIBLE idea, higher your rpm, higher the boost.

if you really want something beastly, get a BOSS or DART block and then boost the ***** off it.

extra cubes + boost in a stock block = no no...

Venomantidote95

Oh yeah i forgot eveyone buys those 2000$ blocks my bad, and i just installed the spacer rings 3 weeks ago for what reason?
It depends on rod length and piston style.
The h and I beam rods with identical rod bolt sizes will both have to be clearanced.
To my knowledge DSS and coast high both offer the 5.315 rods and either or the 5.4 rods.
Like i said before depends on what you want, rpm range will depend on your h/c/i setup, not whether or not you have a blower or whatever adder you use!
Boost will however be limited to your compression ratio, and no your damn compression ratio isnt 9.0:1 because the magazine said you bought 9:1 pistons lmao!

tinman

Get hold of TMD in Riverside, Ca and get the template for grinding the block reliefs. Find them easy on E-bay.com.....
From what I've heard DSS blocks are sort of junk.
Get the machine work done locally....