Got my heads off to do some porting, when I assemble I want to set the spring pressure close to acceptable for the cam. It’s a TA roller, lift is .538 or thereabouts, maybe a tad more. Last flat tappet cam was a TA413, open was 325 lbs closed was 110 IIRC. Machine shop that went thru the heads on last assembly set em up stiffer, Michael’s said they like to see more pressure with roller cams. TA said the springs used for the 413 cam can be used with the roller and I haven’t had any issues. So what’s a starting point, the cam card tells me nothing.
Pressure at the installed height and the pressure at compressed height and then figure out the coil bind. Also a good idea to measure the guide to the retainer distance.
Mark, I'm running the TA super duals. Having some use, the intakes & exhausts were swapped. Was told exh always lose a bit more pressure from heat. Plus I shimmed all springs .060 to bring seat & open up to 135/335. Those Super duals coil bind at .990 so no problem with room at .584 valve lift. Didn't want lifters jumping off cam lobes at rpm.. Check your seal to retainer clearance also. I have a brand new set of Poston PE107 duals, & no wiggle retainers that coil bind at abt 1.100, so the TA's are more forgiving at .990 & allow you to shim them some. Check with TA for their advice. Of course the way to do it would be light 11/32" valve stems, new bronze guides, & maybe beehive springs. Light valvetrain = quick rpm.
I’m reusing the springs, there dual springs from TA, never had issues. I think mine bind @.990 also. Whatever pressure they were at before I just took it apart they were good to 7000 rpm
Mark the spring pressure recommendation should have come on the cam card. Did you get the cam from TA? I had the TA dual springs. They didn't work with my cam and I had to go with Isky.
Cool, thanks Larry, Jim and Mart, I’ll set seat pressure @ 140, and see where that takes open pressure.
Damn Demko I would put a 100 shot on that engine, you almost have the same cam as me but roller and a lot bigger lift not much overlap 113 lsa mine was at 116. The response is crazy on the 350 easy 1 1/2 seconds faster.
Im hoping to get the engine back in this summer, SOMETIME Thats after I port (Ruin, LOL) my heads The way things are going, Im kinda like WHATEVER, LOLOL I've got the mindset now port on the heads when I can. Im SUPPOSED to have hernia surgery, but my crappy health coverage may or may not cover it, so far I've paid 250.00 to see my doc about my hernia, then another 833.00 just for consultation with the surgeon, now its up in the air whether it will be covered. Extra money is supposed to go to Buick stuff, NOT health care
next time you go to Summit I am about 10-15 min away. Open up the heads to match the gasket then just do the spots that have been talked about around the valve. Need a cutaway so you know how far you can go, you already got to a 13.40's. Just a 75 shot like I am using would net you a low 12. hernia can give you trouble so you have to watch straining of any kind, that is your insides breaking thru to the outside, lol somewhat. I know not funny it can be a bitch. when I had obami care I was up to 575$ a month just for the insurance and the gov was paying 200$ more on top of that and I have No issues B/P meds that is it. Same insurance cost me 125$ a month in 2010 before obami care started then went up each and every year and got to 575$ by 2017 and that year I had that kidney stone and the year cost me another 3500$, I spent 10 grand that year on insurance and medical costs. On Medicare now and it costs me 172$ a month plus I get to buy 40$ worth of products from United Care website every 3 months. Plus using my Fitbit and just walk 7500 steps once a week I think and I will get another 10$ a month. I walk 10,000 steps every day now at work so that will be easy.
Seems everything is going to crap these days. I’m probably going to be off for at least two weeks after surgery, They say 4 weeks, so I’m going to have to be VERY careful, I don’t wanna undo what they done
Good question. My original cam card from TA, and what I got back from Crower are 2 different cams. I called Tim and he said that manufacturing specs vary, and basically this is what I got. Cam quoted is left, cam received it right:
Cam on right has slightly less overlap which means it won't be as lumpy but you will never notice the slight change. Spin it to 6500 and go kick Mart's ...... BTW you better get that 850
