Thread: Valve springs

^ You're sort of right, and wrong.

You can go rockers and cam, it just depends how you're heads are clearanced. For example, my cam with 1.8 rockers would put me at .597 total lift. So I would have to get my heads clearanced to at least .600.

Turbo car's benefit more from camming then they do from rockers. Most of the highest HP Turbo 3800s run stock rockers.

So match your valve-springs with the cam setup. I'd run 105's or 150's. 105's if going with a mild cam and shifting around 6k or so. 150's if you're going with a big cam and wanting to shift much higher.

If you go with 105's get Crow Cams. Skip the Comp Cams 105s.

How many times do you want to change valve springs? While 105's will be fine with higher lift rockers and mild cams, there's not much sense in buying 105's if you'll need to upgrade father down the road.

Are you planning on going with modified stock rockers, or roller rockers?? Turbo car's don't care for roller rockers. Again, why most high HP builds use stock.

I personally wouldn't run an old stock timing chain/damper on anything other than stock springs. I would go ahead and replace it with a new stock set if going with 105's/90's. Or go up to a roller set.

There are people rocking stock timing chains with the modded rockers, though if you start raising the shift points I'd be a little concerned.

As long as you have access to compressed air, changing the valve springs is easy.

I think the best thing for you to do is:
Install a set of 105s and new valve seals
Install the modded rockers.

Keep shift tables around 6k.

If/when you decide to go cam:
Choose cam and supporting mods (105's may be enough spring pressure)
Swap modded rockers for stock rockers, sell modded rockers
Install new cam and new timing chain/dampener, or roller chain setup.

If you end up going with a larger cam and want to rev it higher 6500+ then I'd go ahead and put the 150's on, sell the 105's and go with a double roller.

Why is there no option of 130# spring? On my turbo application I went with 105's because never planned on running more than 10psi....and while I'm doing trans work here soon I'll be swapping in 130# springs. I wanted to stay away from having to do a double roller but looks like I'm going to end up doing one anyway.

If you look at a lot of the turbo guys running big power the lowest spring they opt for is the 130....and quite a few run the 150s

Boost it til it blows!

And GMR the only reason I didn't mention the 130's is because most people I've seen go turbo go for an all out setup, and not a more refined streetable route.

I asked a very similar question and the general response is that rockers aren't ideal for turbo setups. Stick with stock cam and keep upping the boost and enjoy. Go cam right off the bat....if you're in the motor far enough to do valve spring and timing chain you're at the point where throwing in a cam would be just one more step.

In general 90 are completely out of the option. It's been shown that the 105's are a better spring and after several people have shown that the 105s with stock timing chain is perfectly fine the popularity of 90's have really phased out.

^ Yep, the exact reason I went with 105'.