Hi..
I´m planing to buy some crane cams

http://www.cranecams.com/import/avteccams.htm. (the 4th one from top down)

Now I need some valve springs for these rpm range. Whats about the valves?? Can I use the stock length??? I´m planing to buy ferrea valves. There is writte that I have to check the valve to piston clearance. I´ve b20/vtec 9.0:1 pistons so I don´t think that the pistons will hit the valvs.. What do you think? Does anybody have some experiences with these cams?

Thanx

 

are you boosting? why do you want to go to 12500? no power band there. crower's, or skunk2 should do you fine. if you boost i would go stainless on intake and inconel for exhaust.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 9sech22civic &raquo;</TD></TR><TR><TD CLASS="quote">are you boosting? why do you want to go to 12500? no power band there. crower's, or skunk2 should do you fine. if you boost i would go stainless on intake and inconel for exhaust.</TD></TR></TABLE>

um thats why hes getting the cams, so there IS power up there.

 

Yes I´m boosting but I want both.. high rpm range and bost.. These are Turbo cams. Take a look on them.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Foozball26 &raquo;</TD></TR><TR><TD CLASS="quote">

um thats why hes getting the cams, so there IS power up there.

</TD></TR></TABLE>

At 12.5k? Who makes cams that make usable power that high? Even more of a concern would be those rods letting go at 12k rpm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTC_CiViC &raquo;</TD></TR><TR><TD CLASS="quote">

At 12.5k? Who makes cams that make usable power that high? Even more of a concern would be those rods letting go at 12k rpm. </TD></TR></TABLE>

holy jesus click the link and read the site, CRANE obviously makes them.

there are alot of race cars that rev to 12k ish so why is his any different?
He never stated whether this is a street car or race car but by the parts hes pick im assuming its race

 

The main flaw on every rood are the connecting rods. There are stronger bolts than ARP bolts available...

 

You would have better luck with this thread in the allmotor forum. I don't know of any turbo cars revving to 12k rpms. Sure there are several all motor race cars that venture above 11k but you have a lot more to worry about than your valves holding up at that point. I cant imagine any turbo cams making power up that high, they simply aren't designed for it and not to mention the extreme amounts of heat that would be produced from 12k rpms and an ungodly amount of proportional boost. Traction would also make those rpms unusable. Many people break loose some decent 24" slicks in third gear still at about 7k so I think that the power up there(if it could be made) would be unneccessary(sp?).

and after looking at it it's a cam designed for a roller rocker system which are pretty rare even among the all motor race catagory. I also think a reason for turbo cars not revving that high is that a head will only flow so much. and at 12k rpms it's gets hard to have a head maintain efficiency.

 

12.5k thats kinda overdoing it, but if you wanna attpemt it go for it. make sure to show pics when the motor goes boom.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTC_CiViC &raquo;</TD></TR><TR><TD CLASS="quote">

Even more of a concern would be those rods letting go at 12k rpm. </TD></TR></TABLE>

*shudders*

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Foozball26 &raquo;</TD></TR><TR><TD CLASS="quote">

holy jesus click the link and read the site, CRANE obviously makes them.

there are alot of race cars that rev to 12k ish so why is his any different?
He never stated whether this is a street car or race car but by the parts hes pick im assuming its race</TD></TR></TABLE>

it has to be a race car!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bEG &raquo;</TD></TR><TR><TD CLASS="quote">12.5k thats kinda overdoing it, but if you wanna attpemt it go for it. make sure to show pics when the motor goes boom.</TD></TR></TABLE>

I just wonder how in the hell the Head is going to stay on at 12.5k! On top of all that on boost!

 

you will sink your valve seats 12.5k and need to go full titanium retainer and Ti - ss valves all around, make sure to check valve installed height upon install and after 500k to make sure. also you will need a spring with atleast 20psi additional closed seat pressure, check the service manual for base figures. you will also need the best headwork you can find to make any power that high. you building a car for DTM - deutsche touring meisterschaft???

 

JGTC too.

 

The reason for going higher in the RPM is for a larger power band, with those cams you have a powerband at 5500-12500 in this case, which is a good 7000rpm's worth of power, on a normal vtec cam engine you will have 5500-9500 or so(turbo power)... only 4000rpm, I would suggest going with carillo rods, H-beam, they have decent bolts as well, however they go for about $290 a piece, or go with Ti pauter rods or something, weight here will be key, also you will need to get lighweight pistons, and alloy wrist pins that are lighter will also help, everything will need to be balanced to the tightest tolerances you can, try and go to .02-.05grams. 10000rpm is about the magical 25m/s mark on a b16, so you can be sure the engine won't last long at higher rpms than this, this is why you can't do this on a street motor... I hope you are not planning a b18. There are other things you should also consider, you will either need to speak to someone who has done this before, to crane/ferrea and ask their opinions, and also do alot of research into high rpm motors.

For the valvetrain you should maybe contact crane or ferrea and ask them...

if you are really adventurous try and build a pneumatic valvetrain, that will handle anything , I have not yet heard of any diy projects to attempt such a thing, however delwest do offer these systems for race use, at about $100000 they are pricey, but not overly complicated for the hardcore engineer...

 

the reason you want to rev higer is the same reason why f1 cars rev to 16+K rpms.

more rpms = more displacement, with the right modifications makes more power..

of course this is a very loose statement

 

well if u want to go that high I'd suggest a seat pressure of 100-120psi @ 1.320", maybe look into EF-1 springs/retainers/cams.

- Fred

 

contact http://www.hondaraceengines.com RLZ has some springs that will do that

 

Actually if you are running Titanium valves you don't need that much since the valves will weigh in at half the weight of ss valves.