351 to 427

[TerrysSPF]

I agree with all of the above. Spend the extra $$$ and get a better block if you want to take it to 427 cubes. Or, if you don't want to get a new block you could always stroke yours to 392 or 408.
I always put a good word in for these guys when someone is talking about stroker kits. They're shop is near me (but they will ship) and I know a lot of people that have used them and are very happy with their products & service. www.dssracing.com

[427supr]

I really don"t want to pay the extra $2,500 for a new block. I can look into stroking it to 408, but I will probably take a chance on my Ford Motosport block and stroke it to 427. I primarily drive the car on the street, without hammering it to often.

[SPF1061]

The Sprotsman block will not reliably support 427 cubic inches.
There's a reason all of the engine builders that warranty their product use an aftermarket block for the 427 stroker.
But, hey, it's your time and money. Spend 'em any way you like.

[carbon777]

A stock block will be fine for street use but lots of track time or over 600 hp you may split the webs. True a Dart block will give you extra insurance but even with a Dart block other things can go wrong....nothing lives forever!

One thing I will say is there is special machine work that needs to take place to clearence the block for 4.170 stroke plus you need to use a small base circle cam to keep from hitting. Your machine work on your block could run ~$600 - $700 dollars. Now if you go with a Dart block and the "same" bore and stroke you will need to machine it too. However most go with less stroke and more bore to get the rod ratio better closer to 1.54 and avoid that extra machine work.

The other thing that kills stock blocks is RPM ......keep it under 6K and it will live much longer.

I currently have a 427w.

Hope it helps.

[Jim Kellogg]

Back to part of his original question...
(I am thinking of upgrading also. I have driven almost 35,000 miles on my SPF with a Ford Motorsports 351/385 with 3.27 diff and 5speed)

Anyone that has moved from 351w (380-400hp) to 427w (500+hp) and want to share the experience? Did the extra hp make a big difference in actual performance (say up to 100mph). Traction is a bit of an issue now, so I would think that would limit the actual performance gain of the 100hp or so...

No doubt there would be a big performance gain above 100mph.

How about some "seat of the pants feel" and actual numbers from those here who have upgraded their cars?

thanks in advance,
Jim

[RACER X #99]

Originally Posted by Jim Kellogg

Back to part of his original question...
(I am thinking of upgrading also. I have driven almost 35,000 miles on my SPF with a Ford Motorsports 351/385 with 3.27 diff and 5speed)

Anyone that has moved from 351w (380-400hp) to 427w (500+hp) and want to share the experience? Did the extra hp make a big difference in actual performance (say up to 100mph). Traction is a bit of an issue now, so I would think that would limit the actual performance gain of the 100hp or so...

No doubt there would be a big performance gain above 100mph.

How about some "seat of the pants feel" and actual numbers from those here who have upgraded their cars?

thanks in advance,
Jim

Jim, I went from a 427FE to a 351 385 HP Ford crate engine. Handled better, no noticable performance difference.
Then from the 385 HP to a 408 CI Dart 600+ hp (leaded race gas)...big difference especially on the track with open headers and slicks. could pass almost everybody with ease.
I had the misfortune to drop a valve in the 408 and was forced to overbore to 4.125 and now I have a 427. I also detuned with less compression,a smaller cam and unported heads.... picked up bottom end torque but lost some top end power. I have not been on the dyno with this combo but based and seat of the pants feel I am guessing around 500HP ( I can now run pump gas but still use 100octane on the track)

You will notice the power over 100MPH

385 HP = run with the stock FE's
600HP= run past the FE's and just about everybody else.
500HP= run with most everybody on the track pass most on the street.

The one thing I have learned is that race engines belong in race cars and a fun track car does not need a race engine.

[SPF1061]

Jim -
I put @ 32,000 miles on a FMS 392/475(?)hp. Replaced it with a Roush 427R/550hp which now has about 14,000 miles on it. With the FMS I was constantly doing upgrades trying to get a little more power. Pro Systems carb, Trick Flow heads... With the Roush I had an AED carb custom built and dynoed for the motor to replace the POS vacuum advance 870 that Roush shipped on the engine. I made that change as soon as I got the motor because I hated the vaccum secondary throttle response. I have not felt the need to make a single change to this motor since then. I have felt the need to put BIGGER BRAKES on the car!!!!
There is a huge difference between the 392 and the 427, both seat of the pants and measurable. The 392 as it came from Ford would run low 12 sec 1/4 mile.
After all of the upgrades I did to it I was running 11:70s. The 427 currently is running 11:30s. I think that when I get my launch perfected I will get into the 11:20s. In short, there is a HUGE difference between the FMS392 and a Roush427R. Hope this helps. Let me know if you have any specific questions.

[carbon777]

Couldn't say never ran a 351 .....went right to 427w