Head Porting Question

[Shane@DBPerformance]

Ok so just clean it up and match the runners and gaskets then? What cams should I run with a 6 bolt swap, wisecos, eagles, and a 20g?

You can clean up the casting flaws, but don't gasket match the runners. I wouldn't take the normal Crower springs/retainers to anywhere near 10,000 RPMs. The Crower springs aren't a huge upgrade from stock, but they are cheap. Good for someone looking to rev to 8500 with not too extreme of a came. If you want to rev higher than that or even run a cam with a crazy profile design then you will have to some stronger springs.

[Halon]

I don't mean to steal your thread, but my question is regarding what's being talked about so I'll just throw it in here. I have the crower springs in my head. Shane when you say you should get something better then crowers to run a cam with a crazy profile, how extreme are we talking? Right now I plan to rev up to 8500, and I'm running 272's. I was contemplating moving up to 280's, or FP3's. What would you say is the limit of these springs?

[Super Bleeder!!]

People have run 8500rpms on 272s with stock valvesprings since the dawn of time.

264s, 272s, and 280s all have the same 10.3mm lift and the same ramp rates, so if whatever spring works with the 272 will work with all of them given the same rpm limits.

[Pushit2.0]

Crower springs and retainers should hold 280s and the revlimit your looking at. The problem with the crower springs is seat pressure, with the more crazy lifts and ramp rates of the big big cams plus high revs you need 280+lbs of spring pressure(pending cam choice), I think the crower gets up to ~190 lbs with a .400" lift, so dual valve springs is the way to get the spring pressure needed for the big big cams. Its good to know comp and fp are the same. I like how easy it is to see the info on FP's site about the cams, and they are a good price.

~John

[Jakey]

Crower information:
http://www.engintecs.com/html/valve_springs.html

[Halon]

People have run 8500rpms on 272s with stock valvesprings since the dawn of time.

264s, 272s, and 280s all have the same 10.3mm lift and the same ramp rates, so if whatever spring works with the 272 will work with all of them given the same rpm limits.

I understand that, but since I had a head with quite a few miles on it, I decided to just go with some new springs because I wasn't sure how worn out the stock springs were. I had my head off, and figured it was a good time just to go ahead and upgrade them to assure that I wouldn't run into valve float.

But I didn't know that all the HKS cams had the same lift, so that's nice to know that I could upgrade to those. I never plan on revving over 8500, and the only time the motor would ever see that kinda RPM's would be when it's at the track, which it hardly ever will be. Are the FP3's comparible in lift to the HKS's? Or would running those on crower springs be pushing it a little bit?

[v8klla]

I'm running Crower 64415 cams with crower springs and retainers, so far no issues up to 8500. I'm not sure what the lift is, but I'm sure that being their race cams it is a significant increase.

Chris

[Pushit2.0]

I have check both stock DSM and Crower springs and found that at a installed height of 1.57"(stock) that the crower is 7% stronger then stock and at ~.460" lift the Crower spring would be 10% stronger then stock. This was a used stock spring compared to the new Crower but I think the 3% stated by Enginetecs is a little low. Crower springs and retainers with a good valve and valve job with be what most need for their dsm. Then if more is need 1mm over and some port work to fit the setup to produce the most power, its all about sizing everything in the setup to work together to net the best results.

~John

[Goat Blower]

The FP3's are designed for the bigger displacement DSM motors and I just heard real good things about them on one of my 2.4's. The FP2's are comparable to the 272's. The x versions of each are a little hairier, but should still be fine on the Crower springs up to the FP3x's.

I'll be upgrading my 272's this winter sometime.

[Halon]

It was after hearing about your friends results that I started thinking about going with the FP3's and ditching the 272's. But I didn't realise they're mainly for the larger motors. I'm still 2.0. I suppose I should just stick with my 272's and just be happy with them.