I know the stock 5.0 blocks handle 500rwhp fairly safely with anything more being an anyday risk. Just wondering what et's people were starting to have problems with broken/damaged blocks? I have seen two break in the low 11's and one break in the 10.70's with a full weight car but was wondering if this is about average? The low 11 second cars both lasted about 2 years before they broke(1 being nitroused--11.50's and the other having a supercharger--11.10's) and the 10.70 car only lasted about 12 passes on nitrous! Is this about what normally would be expected from a factory block or is this bad luck?
What e.t's were you guys running when you broke your stock block?
- Thread starter lt1lt1
- Start date
Times dont always reflect power either. You can have 700rwhp and spin your tires all the way down the 1320 for a time of 12.5. Or you can probably have somewhere in the area of 400rwhp, good suspension and slicks and run 10's. The basic rule of thumb seems to be your safe until around 450rwhp, anything more is a crap shoot. Some break at 475, some can take 650.
Breaking
My buddy broke his @ about 520hp 580tq rear wheel.
The car was a 60k mile stock bottom end and when I
say stock I mean right down to the balancer and all bolts.
Never was apart but to install the cam and trickflows.
Made 16lbs of boost with an s-trim.
I drove the car myself and It prob should have broke the block,
It ran good!
We took it to fun ford and it ran a best of around 10:50 on
the fri night test and tune.
He broke it on the street a couple of months later racing a
fire chicken with a 400 and 2-400 shot plates, but he won.
My 89 is making somewhere around 740 at the fly wheel.
Stock block 30 over, weisco pistons, stock rods, ARP bolts,
windage tray and a motorsport(fluiddamper) balancer.
Running a t-trim and cogs @ 22lbs of boost.
If you look on turbomustangs.com there is a guy from Pheonix
that claims around 680rwhp with a turbo car stockblock.
Heres a pic. of my coupe.
My buddy broke his @ about 520hp 580tq rear wheel.
The car was a 60k mile stock bottom end and when I
say stock I mean right down to the balancer and all bolts.
Never was apart but to install the cam and trickflows.
Made 16lbs of boost with an s-trim.
I drove the car myself and It prob should have broke the block,
It ran good!
We took it to fun ford and it ran a best of around 10:50 on
the fri night test and tune.
He broke it on the street a couple of months later racing a
fire chicken with a 400 and 2-400 shot plates, but he won.
My 89 is making somewhere around 740 at the fly wheel.
Stock block 30 over, weisco pistons, stock rods, ARP bolts,
windage tray and a motorsport(fluiddamper) balancer.
Running a t-trim and cogs @ 22lbs of boost.
If you look on turbomustangs.com there is a guy from Pheonix
that claims around 680rwhp with a turbo car stockblock.
Heres a pic. of my coupe.
Attachments
25thmustang
Mustang Master
500rwhp seems to be the make or break point. With a good tune, you can run more, with a bad tune less. Like the rears its all a matter of luck, and some tuning! If I were budget building, Id stay with a stock block, and tune it right, If I were building it right, Id go with an aftermarket!
Has anyone had any luck using block filler to somewhat strengthen the block? I know it will strengthen the cylinder walls and probably does not do a whole lot for the main webbing but it is suppose to also dampen the harmonics/vibrations of the engine. Would this be worth even an extra 50hp worth of strength? If there is less harmonics/vibrations I would think it would at least take longer to split/crack the stock block. If you are on the edge of breaking a block just 50hp of strength could be worth every penny? Thanks for any reply!!
The thing about fillers and girtles is the weak point on the 302 is the lifter valley, they usually split right down the center. I do belive that a girtle and/or filler would keep the harmonics down some and a good harmonic dampener/balancer to absorb the rest would extend the life/capabilities of the engine.
I have been reading about a new girdle system for the valley and also putting the bottom end girdle in. They say they have ran 1000 HP @9200 for half a season on stock block, these are all claims have E-mailed them they say to watch Don Garlits on June 19th at 11pm and June 30th at 3:30pm (eastern time). Also to be featured on Horse Power TV July 23, 24 and again on October 8, 9 at 12:30 (eastern time).
Oh ya I am running 517 HP stock block only six runs at the track 11.8 ET best, and beat the hell out of on the street, still holding together.
Oh ya I am running 517 HP stock block only six runs at the track 11.8 ET best, and beat the hell out of on the street, still holding together.
washMO66
Founding Member
Naturally aspirated stock block in my 66 (late model roller stroked to 347ci).
I have 500HP at the crank and run 11.40's on 26X9.0X15 Hoosier slicks with stock suspension, 3:70 gears and a 2500 stall.
The car has around 10K street miles on it and less than 70 passes over two seasons and seems solid as a rock.
Also, a main girdle may help a little, at least there will be less pieces to pick up when it frags.
In my opinion the longevity of a stock block is heavily dependant on the quality of your build. I would not associate ET with the capability of the block either as I know that with a few changes to my set up would get me solid in the high 10's (higher stall, transbrake, more cam, gears)
I have 500HP at the crank and run 11.40's on 26X9.0X15 Hoosier slicks with stock suspension, 3:70 gears and a 2500 stall.
The car has around 10K street miles on it and less than 70 passes over two seasons and seems solid as a rock.
Also, a main girdle may help a little, at least there will be less pieces to pick up when it frags.
In my opinion the longevity of a stock block is heavily dependant on the quality of your build. I would not associate ET with the capability of the block either as I know that with a few changes to my set up would get me solid in the high 10's (higher stall, transbrake, more cam, gears)
I have personally ran high 11.90's and low 12's for many years and approx. 150,000 miles without any problems on stock 86 shortblock. I now have an r302 347 stroker and should be easy 10's on nitrous. However I am now building my wife's mustang and would like to have a reliable mid 11 second 347 car using a new 302 roller block. I am at 7200ft in elevation and we have to spray more nitrous and or more boost to get the same times as some of you at sea level which is probably a little harder on the block at the same power level. From my experience with many fellow mustang racers is that a stock 5.0 roller block usually breaks in the mid 11 second zone. If I could use a main girdle and use hard blok in the block to dampen the harmonics enough to get another 50hp out of the block then I should be able to get away with it for quite awhile. If you guys are all starting to break in the mid 11's than maybe I should just save for another r-302!
NakedRaygun
New Member
Mine isn't a sad story, but one of survival. Had a turbo on a 100,000+ mile 302 and it went mid 6's in the 1/8 @ 110 mph (would have been high 130's in the 1/4). It was beat hard and often.
It then had a carb'd/180 shot put to it for many 100 mph 1/8 passes. Motor is still A OK. Maybe it was not running a full 1/4 that helped it out (although it saw many 1/4's and more on the street).
It then had a carb'd/180 shot put to it for many 100 mph 1/8 passes. Motor is still A OK. Maybe it was not running a full 1/4 that helped it out (although it saw many 1/4's and more on the street).
