Advantages and disadvantages of pushrod, modular, and aftermarket blocks...DISCUSS

[BlueOvalStangGT]

Heres what I can think of, post your opinions and I'll add them to the list. Maybe if we're lucky we can make the FAQ! We can use this as a reference so people can choose what block to start their project with.

PUSHROD

STOCK 302
Pros

• Cheap/Inexpensive( Anywhere for free to $150 average)
• Mexican blocks are strongest of the 302 blocks which can be indentified by "Heche en Mexico" in lifter valley and weird bumps on front of engine
• Comes as OEM on most Mustangs
• Somewhat lightweight ~ 135 pounds
• Many different options (ie. 306/331/347)

Cons

• ~550 RWHP MAX in most cases

STOCK 351W

Pros

• No replacement for displacement
• Many different options (ie. 358/393/418
• Somewhat cheap/inexpensive ($50-$150 average for bare block)
• C=60's, D=70's, etc.....ie C9=1969( Apparently the stongest of the 351 blocks due to thicker webbings and higher nickel content

Cons

• Expect to gain 100 #'s from swapping from 302 to 351
• Need new distributer, lower intake manifold, wider fuel rails(or modify stock), new flywheel/balancer, exhaust due to taller deckheight
• ~700hp RWHP MAX- Someone correct me if im wrong this is just what I understood

FRPP Sportsman

Pros

• Marginally stronger then a OEM 302 (Rated at 450 hp, should hande around 600)
• 145 pounds

Cons

• Fairly expensive( I think around $1200)
• Most will agree that cost of this block does not equal benefit

FRPP A4

Pros

• 4 bolt mains
• Very strong ( I believe upwards of 1000 HP)
• Still can be found with a stock bore
• Not too expensive if found used

Cons

• Not available new anymore
• Weight gain with this block

FRPP Boss FMS-M6010BOSS302

Pros

• Available new
• Higher max bore then R block
• Very strong (actual numbers unknown as it is a fairly new block)

Cons

• 2 piece rear main seal
• Splayed 4-bolt main caps on 2, 3, and 4 caps
• Cast Mains
• $1732 price tag
  

FRPP R-302

Pros

• One piece rear main seal
• Nodular mains (Stronger then Cast)
• True 4 bolt mains
• Very strong ( upwards around 1600 hp-correct if wrong)

Cons

• $$$
• Weight gain (160 #'s vs 135 #'s stock)

I dont know very much about the Dart/World blocks so some one please let me know what models they have, I think its just sportsman and other one.

 

[BlueOvalStangGT]

P.S. You modular guys need to help me out here, I dont know ****!

MODULAR

96-04 281

Pros

• OEM in many Mustangs
• Cheap

Cons

96-98 Cobra

Pros

• Aluminum/Lightweight
• Somewhat inexpensive ($150-$400)
• Very Strong (1000 RWHP ???)

Cons

Mach 1 Motor

Pros

• Aluminum

Cons

• Hard to find
• Will twist/flex

03/04 Cobra
Pros

• Very strong (1200+RWHP (???)

Cons

• Cast Iron (not neccesarily bad, just heavier)

If you guys can post about the navigator/aviator/5.4 blocks that would be great, I dont know what to write for those

 

[BlueOvalStangGT]

For deciphering Windsor motors: http://sbftech.com/index.php/topic,175.0.html

 

[mootang]

I know on the dart and world blocks there is expensive machine work required but what about the R block?

 

[blksn955.o]

The 96-98 teksid blocks are the strongest you can get, IIRC even stronger than the 03-04 cobra blocks.

 

[BlueOvalStangGT]

Bump, come on people

 

[Jackie Chan]

gt blocks are the strongest out of all of them

 

[bimmertech]

i will add the benefits of pushrod vs ohc

benefits of pushrod engines:
cam sits lower in the block reducing weight on the top end
better timing due to shorter more acurate chain(s)---less slop


benefits of ohc engines:
less prone to valve float without outrageous spring pressures
better head port flow velocity with more cfm(multiple valve)---has been rectified with LS1/new hemi


as far as the specific blocks go i think you pretty much got it cept for two things:

splayed main caps are not a weakness(con) rather a pro
and all the 4.6's have a skirted crank----big big pro

 

[turbogt]

I'm stuck between a Dart and R block right now...

 

[blksn955.o]

splayed main caps are not a weakness(con) rather a pro

On production ford or factory ford blocks that are not 4 bolt maind' the added bolts actually make the block weaker due to thin casting at the main area. If you look at it the area that the mains bolt to is more like a T with the top of the T were the mains bolt too. The hole (in splayed or reg. 4 bolt ends up weakening the whole area by taking away the support.


Also on an existing non-splayed 4 bolt block the re-drilling of a splayed 4 bolt setup also leaves a weak spot in the casting due to an unfilled hole. With the close prox. of the re-drilled splay hole this opens up the main area for a weak point.

Splayed caps are stronger than a reg. 4 bolt but only if compared in an as cast type setup. In other words they are stonger if it is a aftemarket block that was never setup to be a reg. 4 bolt. Both 4 bolt setups are not a good choice to have done in a production ford or factory ford block if it was the std. 2 bolt setup.