LRS Economy shortblocks forged

LRSjmac · Feb 18, 2010

If you're pushing 450, your flirting with block upgrade territory. While the LRS-6009EF forged piston shortblock will handle a good deal of abuse, FRPP has a smoking deal on a shortblock kit right now. Its a BOSS block, forged crank, rods, & pistons with rings. Basically a build your own bulletproof shortblock setup.

Ford Racing Performance Parts BOSS short block kit

We could put you in that kit for $1899.99 & shipping is only $14.99.

HankyGT · Feb 18, 2010

Yeah, I know it kinda sucks about the block thing. That is a really good deal though on that BOSS setup. I'll have to talk to my machinist and see what it's going to cost for assembly.

I see it will need allign honed for the crank and I'm assuming it is a rough bore? The only 'problem' I forsee is the -6.6cc reliefs. With my 58cc heads I can see this putting me close to 10:1 which is getting out of the safe zone with a blower. That, and the fact that I thought you could not use the tradional 7/16s style headbolts and traditional cylinder heads with that setup. I will also have to do the math on actual displacement.

LRSjmac · Feb 18, 2010

HankyGT said:
Yeah, I know it kinda sucks about the block thing. That is a really good deal though on that BOSS setup. I'll have to talk to my machinist and see what it's going to cost for assembly.

I see it will need allign honed for the crank and I'm assuming it is a rough bore? The only 'problem' I forsee is the -6.6cc reliefs. With my 58cc heads I can see this putting me close to 10:1 which is getting out of the safe zone with a blower. That, and the fact that I thought you could not use the tradional 7/16s style headbolts and traditional cylinder heads with that setup. I will also have to do the math on actual displacement.

LOL I guess if I would have paid a little closer attention I would have seen that you listed 58cc chambers on the head! Unfortunately you'll also be pushing almost the same compression (approx 9.7:1) with the LRS-6009EF. Heck, you're pushing that now with a stock bottom end probably!

Is your motor still operational? You may be best off just buying a good set of dished pistons & re-building your existing motor for the time being.

shelbe67 · Feb 20, 2010

just curious not to hijack the thread but is the boss block finished as far as machinig? also what other parts would you need so it can be finished? ie oil pump ans stuff like that that are boss specific

LRSjmac · Feb 23, 2010

shelbe67 said:
just curious not to hijack the thread but is the boss block finished as far as machinig? also what other parts would you need so it can be finished? ie oil pump ans stuff like that that are boss specific

The block will need finish work only, ie - honing the cylinder walls. The deck, lifter bores, & mains are finish machined to low end specifications & may need minor tweaking for your application. None of this is out of the ordinary for a new block & any machine shop will expect it. The block includes all of its proprietary plugs & dowels. You will need specific head bolts & oil pump pickup, & FRPP recommends the use of their head gaskets.

99FiveOh · Feb 23, 2010

HankyGT said:
That, and the fact that I thought you could not use the tradional 7/16s style headbolts and traditional cylinder heads with that setup. I will also have to do the math on actual displacement.

Yes, I went to the FRPP site and it says this:

"Designed for M-6049-X306//X307/C3/D3/Z304DA cylinder heads. Not designed for production 302/351W or M-6049-Y302/Y303/X302/X303/X304/X305 cylinder heads"

Is this because the block is drilled for 1/2" head bolts? If one were to have their production-style 302 heads drilled for 1/2" head bolts, would they work then? Other than that I'm not sure why they wouldn't work.

Either way, for 1800.00 that is a freakin' steal! Anyone know how much power these blocks can handle "safely"?

LRSjmac · Feb 23, 2010

The_Mustang said:
Yes, I went to the FRPP site and it says this:

"Designed for M-6049-X306//X307/C3/D3/Z304DA cylinder heads. Not designed for production 302/351W or M-6049-Y302/Y303/X302/X303/X304/X305 cylinder heads"

Is this because the block is drilled for 1/2" head bolts? If one were to have their production-style 302 heads drilled for 1/2" head bolts, would they work then? Other than that I'm not sure why they wouldn't work.

Either way, for 1800.00 that is a freakin' steal! Anyone know how much power these blocks can handle "safely"?

You got it! The reasoning is because of the head bolt size. Pretty musch all of your aftermarket heads (AFR, TFS, etc) use 1/2" bolt holes. If you were to have a set of 7/16" hole heads drilled to 1/2", you could most definately bolt them up.

HankyGT · Feb 23, 2010

Common runner aftermarket 302 heads do not use 1/2" headbolts. Only heads setup for large displacement setups. AFR 165cc & 185cc heads both use 7/16", as do the majority of the mainstream TFS line. 205cc + tend to go with the larger bolts.

divit250r · Feb 23, 2010

HankyGT said:
Common runner aftermarket 302 heads do not use 1/2" headbolts. Only heads setup for large displacement setups. AFR 165cc & 185cc heads both use 7/16", as do the majority of the mainstream TFS line. 205cc + tend to go with the larger bolts.

Hmm... my TFS street heads are about 6 or 7 years old now, but they were drilled for the 1/2" bolts and came with hardened washers to use 7/16 bolts if needed. Just an FYI.

Scott

LRSjmac · Feb 23, 2010

HankyGT said:
Common runner aftermarket 302 heads do not use 1/2" headbolts. Only heads setup for large displacement setups. AFR 165cc & 185cc heads both use 7/16", as do the majority of the mainstream TFS line. 205cc + tend to go with the larger bolts.

You're right on the 165s, they do have 7/16" holes. The 185 & up have the 1/2" holes & according to TFS all of their heads are drilled for 1/2" & require a reducer bushing to be bolted down to a production 5.0L block.

BlackVert · Feb 23, 2010

isn't there something about the deck height on the boss 302 blocks that makes them unsuitable for a stroker application?

i think i read that over on hardcore50

so the bottom line is that if you want to use a boss block, you are pretty much forced to stay 302 with it.

but the boss 351 blocks can still be stroked

please correct me if i am wrong about this.

LRSjmac · Feb 23, 2010

BlackVert said:
isn't there something about the deck height on the boss 302 blocks that makes them unsuitable for a stroker application?

i think i read that over on hardcore50

so the bottom line is that if you want to use a boss block, you are pretty much forced to stay 302 with it.

but the boss 351 blocks can still be stroked

please correct me if i am wrong about this.

Huh. I'm definately no expert, but the production 5.0L block was 8.2" deck height as well & there are more of those blocks running stroker rotating assemblies out there than anyone can count. Seems that the BOSS block would be just as suited for it considering FRPP also offers BOSS block based 331 & 347 crate engines.

I'd be interested to read up on that from some more experienced individuals. I'm all about learning as much as possible!

BlackVert · Feb 23, 2010

found it ... it has to do with the bore length, not the deck height ...

Boss b-be Aware!!! - Hardcore 5.0 - The Hardcore Ford Drag Racers Forum

i'm assuming are familiar with these guys ... if they are recommending to not use the boss block, then that carrys some weight with me.

LRSjmac · Feb 23, 2010

BlackVert said:
found it ... it has to do with the bore length, not the deck height ...

Boss b-be Aware!!! - Hardcore 5.0 - The Hardcore Ford Drag Racers Forum

i'm assuming are familiar with these guys ... if they are recommending to not use the boss block, then that carrys some weight with me.

Pretty interesting read; thanks for posting that up!

HankyGT · Feb 24, 2010

The shortblock I was originally inquiring about; what type of hardware does it use?

LRSjmac · Feb 24, 2010

HankyGT said:
The shortblock I was originally inquiring about; what type of hardware does it use?

Uses all stock hardware. Basically its a stock 5.0L block that is machined as necessary & uses stock crank & rods that are machined as necessary & forged pistons from Speed Pro.

5.0_GT_kid · Mar 3, 2010

How much horsepower are those BOSS blocks good for?

LRSjmac · Mar 4, 2010

5.0_GT_kid said:
How much horsepower are those BOSS blocks good for?

According to FRPP, the new BOSS 302 block is confirmed alive & well in several 800-900 hp drag cars around the country. Will it hold more? Probably.

5.0_GT_kid · Mar 4, 2010

LRSjmac said:
According to FRPP, the new BOSS 302 block is confirmed alive & well in several 800-900 hp drag cars around the country. Will it hold more? Probably.

That's pretty impressive. I may just jump up to one of those when I build my engine one of these days.

LRS Economy shortblocks forged

HankyGT

Member

LRSjmac

HankyGT

Member

LRSjmac

shelbe67

Member

LRSjmac

99FiveOh

LRSjmac

HankyGT

Member

divit250r

Member

LRSjmac

BlackVert

LRSjmac

BlackVert

LRSjmac

HankyGT

Member

LRSjmac

5.0_GT_kid

LRSjmac

5.0_GT_kid

Similar threads

LRS Economy shortblocks *forged*

Member

Member

Member

Member

Member

Member

Similar threads

Privacy & Transparency

Privacy & Transparency

LRS Economy shortblocks forged