Mike K.

where can i get a set of these?

also what is needed to put them in,, I hear something about a special pedestal for the springs. Has anybody installed these and can comment on this.

Reason for all this is I'm gonna swap my 918's soon just in case and want to get a good dual spring that requires no machining to put it.

Slowhawk

iTrader: (12)

Thunder sells them as a kit.You have to replace the seats which come in the kit.The only other thing you will need is new valves seals.

jrp

iTrader: (16)

what cam specs are you running?

http://www.thunderracing.com/index.c...yid=1114#T1161

Mike K.

Without pissing JPR off I can say that the cam is pushing the 918's to the limit.

Is this the kit part number?
40-144308-1

I got it from the thunder link that jpr posted.

I have never had to do it before so would i have to pull the heads to install the new seals or seats? These heads are still almost brand new as well so I would think most of the current parts would still be in good condition. If you cant tell I just dont want to pull the heads off if I can help it

jrp

iTrader: (16)

if your doing a dual spring swap then no you dont have to pull the heads. i swapped in rev duals and yours should be no different:

remove locks
remove retainer
pull out springs
remove vavle stem seal
remove spring seat

install new **** in reverse order.

Mike K.

thanks jrp how are those revs? What are they rated to and what is all the rage about these cranes if the revs are holding up.

jrp

iTrader: (16)

i dont even remember what the revs are rated, .625 i think. the revs werent bad but i swapped them out for manley singles with tit. retainers. my cam aint that drastic when it comes to lift so a single is fine. the revs were fine too, i just went another route.

i think the rage about the cranes is just cuz there new :dunno:, if yours is a high lift cam i dont think you can go wrong with either; revs, cranes, or comps 921's.

Beast96Z

iTrader: (21)

The cranes are just the new thing on the market. A very good dual spring that require no machining. Don't forget to air up the cylinders or roll the piston to top dead center on whatever cylinder you are removing the spring from or you could drop a valve. Then you would have to pull the head.

Mike K.

No air here so I will be using the tdc method. Thx for all the advice, I'll probably go with the cranes cause its the "in thing" .

Tally TransAm

iTrader: (17)

i just installed a set of crane duals and so far they are holding up great

they are als very light compared to other larger dual springs on the market

Slowhawk

iTrader: (12)

The Cranes are rated for .650 lift and I think have 10-20lbs more pressure than the 918's.I put them in for a piece of mind with dual springs and that the spring pressure is not as high as other duals.

Mike K.

Can you guys confirm if this is the right kit number?

40-144308-1

Thanks in advance, I heard from a friend of mine that there are several crane duals. I just want to make sure I get the correct ones.

jrp

iTrader: (16)

i'd call up thunder and see what exact springs come with the crane kit. i added up buying the springs, tit retainers, hardened spring seats, and valve stems and its about 376. the kit is 329, could just be a savings or it might be another spring. i'd find out for sure.