|03-16-2011 03:13 AM|
I agree, tighten up the lash, makes the cam seem bigger to see if the engine wants more duration.
I looked up the head flow on the Enginequest web site and on Stan Wiess' independent head flow site, and I wouldn't expect them to be the cork, the #'s look good.
This is a real head-scratcher.
|03-16-2011 02:33 AM|
|iambigperm||Cam is not advanced. I did degree it when I installed it to make sure it was correct as well. I'll try the tighter valve lash to see if it helps out at all this weekend.|
|03-16-2011 01:05 AM|
UPDATE! Made it to the dyno!
Finally made it to the dyno at Wicked HP this evening. HP was peaking at 5700 rpm and dropping off from there, exactly as it felt. Made 356hp/358tq N/A and 458hp/485tq on a 125hp nitrous shot. Before i went to the dyno I locked the distributor at 36 degrees. After a couple of pulls I found that it made the best power at 38 degrees. After all the passes the only two things that the shop thought might increase those numbers with my combo was to port the heads or try shimming the valve springs to see if it helps. Given my setup they thought it should peak at 6400 rpm or higher. I think I'll try shimming the valve springs since that is relatively easy. I know I have a lot of room on these springs before they would bind. Anybody have any other ideas?
|03-05-2011 05:03 PM|
|cobalt327||It is likely- given the stock spring length- that these springs are installed at a shorter installed height than the 1.9" spec given by Crower. That would account for the higher seat pressure. That will also lessen the amount of lift that's available until spring bind is encountered.|
|03-05-2011 03:49 PM|
|iambigperm||I'm starting to wonder if I'm chasing my tail. Could this combo just run out of steam at 6k? I'm hoping to dyno this week and maybe that will give me some ideas. My old solid flat tappet cam with .520 lift and 041 heads revved higher than this with the same bottom end.|
|03-05-2011 03:44 PM|
|iambigperm||As for the installed height, I can't remember what it was. I'd have to pop off the valve cover and check again. They are installed with the retainers and locks that came in the kit. There were no shims needed to get these pressures. The valves are stock length.|
|03-05-2011 03:38 PM|
|03-05-2011 02:31 PM|
|iambigperm||Just got back from testing the springs. They were 190 seat/450 open using an on-car tester. I found the box the springs came in and they are the 68385x2 springs and retainers. These number appear to be spot on for that part. I think this should be enough pressure, but my machinist said he likes at least 240 on the seat for a solid roller and did recommend heavier springs. I'm really not sure where to go from here...|
|03-03-2011 01:08 AM|
|03-03-2011 12:44 AM|
|ericnova72||Keep posting, I'm curious to see how this turns out.|
|03-02-2011 10:13 PM|
|iambigperm||I spoke with Dave Crower this afternoon about the low spring specs and strange spring part number on the cam card. He said they do run springs on the light side with their street rollers and that I may need to go with a heavier spring. It sounds like that spring part number is a typo on the cam card. As to whether the spring specs were a typo as well I didn't really get a direct answer. He said if I ended up needing heavier springs that they would help me out with some at a good discount. He was pretty helpful. I can't imagine how many calls they get a day. Next step is to actually recheck the springs I have. I'll do this on Saturday.|
|03-02-2011 03:35 PM|
|sri3850341||i need that body work!!! and your gen vi has turned into a 498 monster with rect heads!!!!|
|03-02-2011 03:29 PM|
|iambigperm||We actually moved by Nellis now. Much better commute! And yes those heads you sold me have been working great.|
|03-02-2011 02:42 PM|
|sri3850341||speaking of the speedway, do you still work out north by apex??|
|03-02-2011 02:25 PM|
The ignition timing is 20 initial plus 16 degrees advance. All in by 2500 rpm. No vacuum advance. I did check the timing marks when I assembled the engine and they were accurate.
I was hoping to dyno this weekend and then I remembered its NASCAR here this week... The dyno I would be using is at the speedway and I'm not going near that traffic disaster.
|This thread has more than 15 replies. Click here to review the whole thread.|