Anders - check out this thread -- http://www.corral.net/forums/showthread.php?t=569936

And here's a link that will help you understand some of the variables regarding rod angle, side loading of the cylinder and rod length/stroke ratio implications.

http://www.victorylibrary.com/mopar/rod-tech-c.htm

 

simple...don't believe the hype and go for the cubes

 

408 is still a small block.. mcuh easier to fit in the car, and must be a lighter motor than a big block! You can also reuse lots of parts from your 302.

 

um, i am no stroker expert, but i am pretty sure the 427 is a small block as well man...a very large small block no doubt, but both are based off the 351W block...

PONY1 is right man, dont jump off the bridge cuz everyone else is... build that baby! and you can wear a cool badge too. 427 dang, that would be awsome!

 

Mav - Jeckle's right; Anders is talking about a 427 based on a 351. It's a long-rod 351 bored .060" over and with a 4.125" stroker crank instead of the stock 3.50" stroke crank. About the most cubes you can get out of the 9.2" deck height small block.

 

Ah ok. Sorry guys, I had never heard of a 427 coming from a small block! I think the .060" over would freak me out a bit though, i'd vote for the 408.

 

Thanks Michael for the link.

Let me be more specific. I´m in particular thinking of buying a Roush crate engine and they have 2 versions that I´m considering.

You can see specs and prices on this site:

http://www.stage3motorsports.com/CRATEENGINESHOME.html

The 402 stroker, Sportsman block, forged rotating assembly, 185 heads rated at 515hp/500tq. Price is $ 12.200 (polished version). Possible Dart block upgrade for $1000.

and the 427, Dart block, forged , 205 heads rated at 550hp/535tq. Price is $ 14.200 (polished version)

The engine will be coupled with a 6 speed manual transmission in a ´68 Shelby Hardtop clone. Pretty light car as well.

I don´t really think there will be much difference in the performance numbers as I do believe traction will be a real challenge anyway.

The 427 is more expensive but I´m really sure that for my use, that I will see/get the benefit of this. Only thing is the magic that the 427 number brings, ut on the other hand, this particular Shelby prototype apparently went through a number of different engine combos and therefore one could argue that there really is no "original" engine for this car.

So I guess that everyhing points towards the 402 then??

Thanks
Anders

 

there is no replacement for displacement, Go for the 427, you can go even bigger with the 4.125 bore dart block that takes you to a 440. there may be some extra skirt wear from the side loads caused by the longer stroke but it's not like your looking for 200,000 miles out of this engine.

 

I guess I'm wondering if all the options suggested aren't overkill given how you've said you're gonna use the car. But only you can decide that Anders. I'd start a dialoque with Roush about building a 400 (range) cubic inch stroker, but with a cam choice aimed not at 500-550 HP, but maybe something like 400-425 with an even fatter bottom end and mid-range. That's something that would be REALLY fun to drive as the occasional summer cruise car.

 

I'm with Michael - those high hp numbers are great, but where in the rpm range do they occur? I would go for something with peak power lower in the rpm range, where you will spend the bulk of your driving time...

Wow, that's a lot of coin for those motors. For that cost, you could do a fuel injected 351 with nice blower on there - that would be cool as well, and you could hit similar power levels...

 

He's in Finland Richard - kind of needs someone to be able to ship it over all buttoned up and ready to go. Carbs on a big-inch stroker are a bit easier to manage/trouble shoot/repair/tune over yonder.

 

Oops, didn't notice that part...

 

I also think its a lot of money, and I also know that I could go much cheaper route if I bought a little here and a little there when the price was right.

As I live in Denmark (not Finland Michael), the cost of having parts shipped is high. If I buy parts seperately the total shipment cost will be insane as where it will be high but not crazy if I get a complete engine over in one shipment.

Maybe I save a total of $ 1500-2500 by having everything sent in one shipment. If I then buy parts seperately I´ll have to find a machine shop to help me with some of the stuff.
Again it will add alot to the cost as there are very few and they are expensive etc.

Also I have my previous turn key engine experience in mind. I bought a engine from Total Performance which was assembled wrong and had to be rebuilt after less than 30 mins operating time. Imagine that!!
That 347 in my ´94 vert has cost me about the same as if I had bought the Roush 427 AND a T56 !!

I just have to accept that it will cost me a small fortune no matter how I do it, so that´s why I don´t think the pricing is that crazy it for me is

* easy - turn key
* high quality - tested and with guarantee
* Reasonably priced

About the hp/tq numbers, I thought Roush already had spec´d it to be good on the street rather than an all out race engine?

I´m very open to any suggestions you have. No final desicions have been made except for the testing/dyno/guarantee part is a must.

Anders

 

Well, since you're shooting the wad here. I'd go with the large bore Dart block (4.125) and put the 4.00 stroker crank in it. It'll give you the 427 CI that you like. The large bore will unshroud the valves and the 4.00 stroke will still let it rev pretty well.

That may be exactly the combo in pick #2 since there aren't many details. Also, I would go with AFR 225 on something that big but if your buying it as an assembly, they may not give you that option.

All I can say is Damn, that's alot of coin.

 

Sorry for the country mixup Anders - Denmark, I'll try and remember. You'd think I just lumped all those Scandanavian countries together.

I'd talk to Roush about the 'streetability' of their 500+HP 'small' blocks. It's important to understand that before you plunk down $10K+. Be sure you understand what you want and what there's will do. I'd like to know what rpm they'll reasonably idle at, how much vacuum they make at idle, how comfortable they'd be lugging around in 4th gear at 1200 rpm. With 400+ cubes you can definitely have something with plenty of power on top, and reasonable drivability down low. But if I were in your shoes, I'd want to ask Roush about their engines.

 

I believe oth Kieth Craft and DSS can build a turn key engine and also dyno it. On the website of Stage3motorsport they say 3 year/50k miles on the DSS engines

 

Mav - Jeckle's right; Anders is talking about a 427 based on a 351. It's a long-rod 351 bored .060" over and with a 4.125" stroker crank instead of the stock 3.50" stroke crank. About the most cubes you can get out of the 9.2" deck height small block.

Michael,
The 427 is based off a 4.03 bore and a 4.17 stroke using a stock 351w block which is a 9.5 deck block(9.48 in 69&70). The 9.2 deck block is the 351C or an SVO or Dart short deck windsor based block. You can achieve 434 from a stock 351w block and close to 450 from a Dart.

 

The Roush 402 is based on a Sportsman block. Is the 351 Sportsman as weak as the 302 sportsman?

 

Lee - thanks for catching my deck height typo - cleveland is 9.2/windsor is 9.48/5. How does anyone know how a particular displacement is reached by a particular builder when so many different stroke lengths are available cast and billet?

 

The Sportsman II 351w block is very strong and unlike its 302 counterpart wont break on start up

Michael,
The original 351w to 427 stroker was the 4.03 X 4.17 which is harder to come by these days as everyone has tried to standardize stroke combos, Alot of companies try to pass of a 4.06 X 4.1 = 424 as the 427 because its much more readily available and cheaper. Either way .070 stroke isnt much and only adds 7 cubic inches to the equation.
My 418 is 4.03 X 4.1 and uses a 6.2 length rod with a 1.23 comp height piston.

 

Thanks for the background Lee -- "Alot of companies try to pass of a 4.06 X 4.1 = 424 as the 427" -- even the factory did it; one of the mid-60's FE combos was actually 425 cubes that they called a 427 because of the brand/market power of the engine size.

 

Yeah but the FE 427(4.23 X 3.78) evolved from the 406(4.125 X 3.78) which evolved from the 390(4.05 X 3.78). But for comparison sakes the 428(4.125 X 3.98)was actualy 426ci but was marketed as the 428 except for in a few 427 Cobra roadsters which had 428s but were marketed as 427s. I grew up with FEs and am very fond of them still.