Can it make 600fwhp.....High Riser 427

[HR427]

Im am planning on putting together a stock stroke 427.  Was looking for input to see if im dreaming or what.

427 4.250 bore
$ crank, molnar rods, dome diamonds 13/14-1, low tension ring set
unported F HR heads 2.19/1.72
Unported D manifold
Solid roller
CU/CV carbs

Can these basic componets get me close to 600 fwhp?  Thanks

[427LX]

Should be able to hit that number with 10.5 compression!

[HR427]

you really think so?

[CaptCobrajet]

That is absolutely realistic.  With the right prep and parts selection, very doable.  I have done extensive R&D on stock stroke High Risers for Stock Eliminator racing. We are 700+ on power now with .525 lift flat tappets.  With the right solid roller, it can make notably more power than the Stocker cams.  The D manifold is slightly down from the F, but it is the correct manifold for what came on the cars.  The F was the improved replacement part. 

[Joe-JDC]

That unported  F head will only flow 285/190 cfm.  It will be a real stretch to hit 600 whp without porting the heads and intake.  Crankshaft horsepower is going to have to be about 20% more than the wheel horsepower.  JMO, but I just finished two sets of HR heads and intakes, and they respond to porting with great success.  Joe-JDC

PS I just re-read the title, and flywheel horsepower is possible. 

[HR427]

I would actually love to use a solid flat tappet. 

This will have a faceplated TL in a 64 galaxie that weighs roughly 3750

Thanks for the help fellas.  I may contact some of you for parts. 

[GerryP]

Don't use a flat tappet unless you are racing in a class requiring a flat tappet or your budget is too thin for a roller.  It will be more difficult to reach your goal with a flat tappet.

Flat tappets have their place and are certainly appropriate for most builds.  But you have a horsepower goal that pretty much automatically elevates the budget consideration.  And in that regard, much like you wouldn't opt for a cast piston, you want to make room in your budget for parts that are compatible with your goals.

[blykins]

I would actually love to use a solid flat tappet. 

This will have a faceplated TL in a 64 galaxie that weighs roughly 3750

Thanks for the help fellas.  I may contact some of you for parts.

What block are you using?  Undrilled?

[HR427]

solid lifter marine

[blykins]

solid lifter marine

Keep in mind that a solid roller lifter that can’t be pressure fed won’t last nearly as long.  The lifespan will be fairly short, especially with rpm and spring pressure.

A solid flat tappet isn’t really a bad idea, but even a solid flat tappet will need to be calmed down a little since you cant use a lifter that benefits from oil pressure.

I’m doing a high riser build right now and will be using a solid flat tappet with a center oiler.  It has a nitrided cam and tool steel lifters but the lobes are such that it will live on the street.

[427LX]

Wheel horsepower is going to have to be about 20% more than the crankshaft horsepower.  JMO, but I just finished two sets of HR heads and intakes, and they respond to porting with great success.  Joe-JDC

PS I just re-read the title, and flywheel horsepower is possible.

How can HP at the wheels be 20% more than at the crankshaft/flywheel???

[Stangman]

well I believe Joe is saying that you need 20 percent more at the flywheel. So if you want 600 at the rear wheels then you need 20 percent more at the flywheel.

[CaptCobrajet]

Don't use a flat tappet unless you are racing in a class requiring a flat tappet or your budget is too thin for a roller.  It will be more difficult to reach your goal with a flat tappet.

Flat tappets have their place and are certainly appropriate for most builds.  But you have a horsepower goal that pretty much automatically elevates the budget consideration.  And in that regard, much like you wouldn't opt for a cast piston, you want to make room in your budget for parts that are compatible with your goals.

All correct info!!

[wayne]

I know newer grinds are better but how would the old 600-330 factory cam work in this how much did they make back then.

[CaptCobrajet]

Those old flat tappets were really "slow" lobes compared to now.  Valve springs are about 900% better now.  Some of the older grinds will rpm with light valves and light retainers, as they did in the day, but they hurt bad for bottom end and mid-range.  I would say that cam would struggle to see 600 hp.  There are creative ways to control the valves nowadays.  Lobe design has come light years, and keeps getting better.  CNC cam grinding has eliminated having to make masters just to try new ideas.  It's on the screen and keyboard, and then BOOM......new design.  We explore stuff now that would have been unaffordable before the CNC cam grinders cam along.

Also, new spring materials, ovate wire, conical and beehive innovation has brought lightweight and effective springs that require less pressure to do their job. 

Roller lifters didn't have the pee holes for many years.  Pressure fed oil is absolutely better, and required for bushed rollers, but a person can get creative with the cam lobes, valves, valvetrain, and springs, and do things now that really work well.  Things that had not been possible until recent years.  A severe duty Crower, non HIPPO with less than 600 open pressure can live pretty good in the right set up.  No doubt a roller is the OP's best option if there are no rules to prohibit.