girdled 347 vs 4 bolt main

[Pitbull1052]

Since someone posted a question about a 347 with a girdle I have a question. I currently have a rotating assy for a 347 based motor but no block due to the previous one pretty much exploding a stock based block 347.

My question is I've been thinking of just buying a new Boss 302 block being as it's a 4 bolt main, but due to the obvious cost I've been thinking that maybe a girdled xxx block or something might be o.k. I guess my question is what kind of numbers can a girdled block handle vs a 4 bolt main block.... HP range is going to be in the mid 500's. occasional track duty mostly street

[Sloney50]

Ive seen Girdled 347 put 600 to the wheel and do ok. But now for the longevitiy? Dont know :confused:

Ill be 400 to the wheel and I opted to have it girdled just in case........

[Pitbull1052]

Ive seen Girdled 347 put 600 to the wheel and do ok. But now for the longevitiy? Dont know :confused:

Ill be 400 to the wheel and I opted to have it girdled just in case........



good choice if you wanna see what one looks like that hasnt been stop by sometime lol I live really close to east fork...... this one put down 382 I think.... then around 505 with the super charger.... then BOOM!!! I don't want anymore booms....

[blue5.8]

can i see?

[Pitbull1052]

can i see?



you've already seen it

[03z06vette]

More of a question is ballance and hardware. boss blocks are prone to breaking cyl skirts. Id steer clear of them. Go with a girtle.

[Pitbull1052]

More of a question is ballance and hardware. boss blocks are prone to breaking cyl skirts. Id steer clear of them. Go with a girtle.



it's all brand new eagle crank, h beam rods, je pistons.....

[Walter]

More of a question is ballance and hardware. boss blocks are prone to breaking cyl skirts. Id steer clear of them. Go with a girtle.

No, they are not.

[Sloney50]

Walter you have a boss block?

[Sloney50]

good choice if you wanna see what one looks like that hasnt been stop by sometime lol I live really close to east fork...... this one put down 382 I think.... then around 505 with the super charger.... then BOOM!!! I don't want anymore booms....

I think I will!

[Walter]

Walter you have a boss block?

Nope.

[Blowpastyou]

The new boss block has proven reliable to 1200+ whp... All a girdle on a stock block is doing is delaying the inevitable.... An keeping the parts in a nice lite pile when it comes apart.

[Sloney50]

The new boss block has proven reliable to 1200+ whp... All a girdle on a stock block is doing is delaying the inevitable.... An keeping the parts in a nice lite pile when it comes apart.

I like nice clean piles.......Dont have to get the broom out! :lol::lol:

[Blowpastyou]

When the block breaks it will more than likely take some of the rotating Assembly with it. Something else to think about

[dsmawd350]

Rob On here had a healthy 347 in a girdled block at around 450+ id say N/A. He blew it up. All the girdle did was keep the block together when it blew lol

[Sloney50]

Yeah Im sure it will be all scrap........Only a joke until it happens to someone

[Walter]

No girdle here.

[Gearhead]

More of a question is ballance and hardware. boss blocks are prone to breaking cyl skirts. Id steer clear of them. Go with a girtle.

Huh ?? You're saying a girdled stock block is stronger than a Boss block ??!!

Girdle does about nothing other than holding the pieces together when the block breaks.

The Boss block has some quirks, but it's relatively strong.
Best deal going is probably a Dart SHP.

[Pitbull1052]

I've got a nice pile from a stock block no girdle it snapped the crank in half bent two rods into nice S shape the crank was sticking out two inches past the timing chain cover gauges the pistons to hell and back even sheared teeth off the cam broke the gear on the dist but I've got all new rotating assy I just don't want to do this again

[Jeff88coupe]

The cylinders walls in a BOSS block are a bit short for use with a 3.4" stroke crank (normal 347 kit). For what ever reason Ford made the boss block cylinders a bit shorter than a stock block...this causes a 3.4" stroke/5.4" rod combo piston to come out of the bottom of the cylinder bore enough that the piston will "rock" some. Has lead to cracking/breaking of piston and cylinder wall skirts. I would go with a Dart SHP as the cheapest route, or find a used R302,A4,Dart block.

[Pitbull1052]

The cylinders walls in a BOSS block are a bit short for use with a 3.4" stroke crank (normal 347 kit). For what ever reason Ford made the boss block cylinders a bit shorter than a stock block...this causes a 3.4" stroke/5.4" rod combo piston to come out of the bottom of the cylinder bore enough that the piston will "rock" some. Has lead to cracking/breaking of piston and cylinder wall skirts. I would go with a Dart SHP as the cheapest route, or find a used R302,A4,Dart block.




That's what I needed to hear thanks Jeff! now just to find a used block i'm still not sure what to look for

[Walter]

Ive read that about the cyl wall being short for a 3.4/5.4 setup, but have yet to see anyone that had an actual problem with it. Boss big bore 363's out there going low 8's, cant be that bad.

[Rob]

i had a girdle on a stock block, it was magnafluxed, bored, honed, decked, the works, it split around the mains. the girdle is the only thing that kept it together. all it did was spin one cam bearing and drop oil pressure. everything was fine. i put it all in a mexican block with the same work done and it held up. i would go 4 bolt, you have thicker main webbing and a stronger lifter valley. if you decide to go that route let me know

[Pitbull1052]

i had a girdle on a stock block, it was magnafluxed, bored, honed, decked, the works, it split around the mains. the girdle is the only thing that kept it together. all it did was spin one cam bearing and drop oil pressure. everything was fine. i put it all in a mexican block with the same work done and it held up. i would go 4 bolt, you have thicker main webbing and a stronger lifter valley. if you decide to go that route let me know





I would prefer to go 4 bolt just hearing mixed reviews of the Boss so I'm not really sure where to go from here. .

[AntiRice427]

Everybody keeps saing the girdle is the only thing keeping the block in one peice when it splits. Even without a girdle its all going to stay in one peice because of the main caps. Are you telling me that all the main caps split to??

[Pitbull1052]

On mine it was a xxx newer block, no girdle and it split so many ways it's not even funny....... and yes on mine the mains split too but again it was just a 2 bolt xxx late model block.

[Rob]

Everybody keeps saing the girdle is the only thing keeping the block in one peice when it splits. Even without a girdle its all going to stay in one peice because of the main caps. Are you telling me that all the main caps split to??

no the caps didnt split, the block split from the distributor thru the lifter valley almost clear to the back of the block thne down thru the cam journals, once the crack hit the cam journals it forked and went to each main stud. after i removed the girdle i took a hammer and knocked out the main webbing with no effort. if the girdle wasnt on the mains would have fallen out.

[03z06vette]

Huh ?? You're saying a girdled stock block is stronger than a Boss block ??!!

Girdle does about nothing other than holding the pieces together when the block breaks.

The Boss block has some quirks, but it's relatively strong.
Best deal going is probably a Dart SHP.

It doesnt sound to me he is looking for 1200hp. Im saying a boss block is overkill for he application. A ballanced short block and girtled should be fine for him. Id go for a 4 bolt 351 insted of a 347 anyway.

[Jeff88coupe]

Ive read that about the cyl wall being short for a 3.4/5.4 setup, but have yet to see anyone that had an actual problem with it. Boss big bore 363's out there going low 8's, cant be that bad.


Over on Hardcore5.0 forums...guy built a standard crank/rod based 363. Ran good but soon had issues...piston skirt or 2 were cracked when he tore it down. I think there is another 347 rod/piston size option that keeps the rod pin higher in the bore at BDC so it doesn't have the rocking issue.

[Pitbull1052]

Tom you are correct I'm guessing at the most I'd ever want would be is around 550 ish depending on boost, and the reason for the 347 is I have a brand new rotating assy, crank, pistons, rods, cam, etc...... that and well a 347 just sounds BA anyway lol.... but that's the reason mostly.... secondly I'd just rather stick with a 302 based motor.....

[NXcoupe]

I run boss blocks in my race car. I have two of them. One is getting ready to be assembled if you want to look at it sometime. Also, is your crank forged? Are the rods H or an I beam with a through bolt and not a nut and bolt style? If not, then a boss block or another 4 bolt block will hold more than the internals. Just a thought. I made 600 to the wheels with my girdled stock block, no would not recommend it, but I wanted to see how it would work. I broke another one in two on nitrous years ago before I bought the R block for my renegade car. I reused every piece in that engine, just needed to have the crank polished is all.

[jack90gt]

I run boss blocks in my race car. I have two of them. One is getting ready to be assembled if you want to look at it sometime. Also, is your crank forged? Are the rods H or an I beam with a through bolt and not a nut and bolt style? If not, then a boss block or another 4 bolt block will hold more than the internals. Just a thought. I made 600 to the wheels with my girdled stock block, no would not recommend it, but I wanted to see how it would work. I broke another one in two on nitrous years ago before I bought the R block for my renegade car. I reused every piece in that engine, just needed to have the crank polished is all.

:eek:Damn 600 to the wheels on a stock block.....:bigthumb

[Pitbull1052]

Nx is Mike from dp right? Yes I would like to check ur build out my new rods are h beam my pistons are je dished for boost crank is an eagle forged and cam is a flowtech custom ground the rest of the combo is Vic jr 1.6's holly intake some know this car Walter does for sure it's been put together well just need a new block

[bangingears]

http://www.theturboforums.com/smf/index.php?topic=70933.0

no girdle, 23k miles, been together since 2005. been de-tuned to 540rwhp since. If you are going to build something do it in a decent aftermarket block. If you are throwing something together, stock will work. There is hundreds and hundreds of stock block cars making 4-500 hp

[Pitbull1052]

I'm building something so I'll go with a good aftermarket block...

[Pitbull1052]

I would go with a Dart SHP as the cheapest route, or find a used R302,A4,Dart block.




what are the chances of finding one of those used? and any idea what they are going for?

[NXcoupe]

Nx is Mike from dp right? Yes I would like to check ur build out my new rods are h beam my pistons are je dished for boost crank is an eagle forged and cam is a flowtech custom ground the rest of the combo is Vic jr 1.6's holly intake some know this car Walter does for sure it's been put together well just need a new block

You're welcome to come up, I'll be here for the rest of the week from 9 til 6, stay later on Tuesday's and Thursdays to work on my own stuff and help a buddy out on that red GT. Just give me a shout.
Just wanted to make sure the rest of the internals were up to what the new block could take. Sounds like you have it covered.

[Pitbull1052]

You're welcome to come up, I'll be here for the rest of the week from 9 til 6, stay later on Tuesday's and Thursdays to work on my own stuff and help a buddy out on that red GT. Just give me a shout.
Just wanted to make sure the rest of the internals were up to what the new block could take. Sounds like you have it covered.




so thursday you'll be working on it late? I get off work at 3:30 prolly take me an hour to get up there.......

[Walter]

what are the chances of finding one of those used? and any idea what they are going for?

I havnt even seen a used SHP yet. A4 or r302 used will be about 1k and most likey been sleeved.

[Gearhead]

Here's a B50 block, not sure of the HP rating though...

http://forums.corral.net/forums/showthread.php?t=1261257&highlight=b50

[Blowpastyou]

Dont waste your time on this ^^^^

[NXcoupe]

so thursday you'll be working on it late? I get off work at 3:30 prolly take me an hour to get up there.......


Yep, I'll be there pretty late. We'll be putting the TKO into that red GT with the 427 in it. I will have the Boss block up on a stand so you can look it over. c ya then.

[Pitbull1052]

I'm gonna try to make it Mike.....

[Pitbull1052]

Dont waste your time on this ^^^^





how come?

[Pitbull1052]

From the 2004 FRPP catalog:

"Extensive dynamometer and in vehicle testing has confirmed that this block should not be used for engines exceeding 450 HP @ 6000 RPM." (this is PN M-6010-B50)

PN M-6010-A50 (the Street Production Replacement) is rated at 400 HP.

PN M-6010-R302/M-6010-S302 (Professional Competition) are rated for 1200 HP @ 8500 RPM

Specs for the Aluminum Race block are not listed.




and it's a 2 bolt main guess I'll check out the Boss or the Dart and go from there....