We are talking STOCK 500efi here that turn 5350 rpms, not super modified Drag boats. What info do you want to post?
Dave
On the crane cams website, under frequantly asked questions, at the heading below, "reasons and causes for cam failures" I wanted to post that topic, as it states spring pressures for Hyd. roller, street performance BBC's.. Yes, it does not say boat, but I build my mild boat engines as basicly street car performance style, of course with some exceptions. But come on, a low rpm, well thought BBC is very comparable, whether its a car, boat, or ?? The bottom line is HP-TQ at the right rpm, with reliability. Although, some boat engine builders would like to think there is a black art to building offshore engines, the none racing performance offshore engines are some of the lowest stressed BBC's I have ever built, but again, I'm comparing exp. I have gained from trying to keep very high stressed applications together, such as blown gas-alky, injected nitro drag-boats. Although very different, agreed, I have learned a few things along the way that correspond with the basic mechanics and design of engines & componets regardless of what it is, from the dyno or actual implement its going in. The last page I wanted to post was from the Competition products, inc. website. If you go under valve springs, and then Isky, you will see the 8005's with the specs. That is where I buy my springs from, and probalbly have over 50-engines out there with hyd. rollers and that exact spring. Also, my Rimac tester, verifys the numbers listed from comp. products, dead on. Thats it, sorry for all the BS.
bob
12-28-2007 10:12 PM
I am no cam wizard but I can tell ya I tried running a Tool Room Sp that went in new around 250 at the seat, with .720 lift on a solid roller. That was the ticket I guess for 7500 running but it was not good on lifter life. Switched to an Isky Plus which has I believe a tool room outter and a lesser inner spring and they go in around 200, end up around 185 or so after dyno and life has been good. My experience with the pressure drop after break-in is almost 10%. There are some builders suggesting that you want 180# or so with a hyd roller. I think I would look at that a little closer for a boat app.
formula 382 sr-1
12-29-2007 01:10 PM
Yup 8005 sp for me two new sets of AFR's 315 with them on them.:D
Quinlan
12-29-2007 01:40 PM
Wow all this back n forth and no one even said the Fountain word.
formula 382 sr-1
12-29-2007 01:43 PM
Originally Posted by oklaoutlaw
(Post 2386634)
Wow all this back n forth and no one even said the Fountain word.
WOW !!! I would have never guessed valve spring choice would be such a hot topic. Thanks for the input guys. I will start researching the part numbers offered.
