2001CamaroGuy

iTrader: (6)

My heads have Comp 987 duel springs (have 20,000miles) in them. I am looking into swaping out my TR224 for a G5X cam. Can I just do a cam swap or do I need to replace/upgrade my valve springs?

SPANKY LS1

iTrader: (24)

I don't think 987s will hold that much lift, I'm going to be running 977s, and I know some like the REVs. I originally was looking into swapping my TR230/224 for a G5X2, and was under the impression that the 987s would need to be replaced, but not sure.

Shawn

2001CamaroGuy

iTrader: (6)

what lifters would I use with a spring like that?

FDLS6

iTrader: (4)

I'm voting for no on the 987's I hear that a set had valve float on the g5x2 recently... check out 977's

Louis

iTrader: (7)

Indeed, they do not have the control at 6k plus. Isky 295 Ds, REVs, or 977s will be just fine.

2001CamaroGuy

iTrader: (6)

987s are rated at 130 @ 1.800" and 325 @ 1.250"

977s are rated at 160 @ 1.850" and 440 @ 1.250"


that seems like a lot of spring pressure for hydraulic lifters (or no?)....

AZ Power & Sound

iTrader: (2)

I like my REVs... call LG Motorsports and get Lou or Louis to sell ya a set... their customer service is BEYOND great!

verbs

um, your G5X-2 cam has already broken two of your rev springs in only what, 2 months?...that's a pretty bold statement there.....

JF WS6

That's funny.

I'm running Comp 987's set up by Jay at Absolute and he informed me that they should be fine with this cam, as I personally asked him about it. A quote from him:

"they are plenty of spring for that cam, some people look at a comp cam book and see that they are the recommended spring for old small block chevy cams that dont go much over .500 lift, the way i set up the 987's they have 20lbs. more on the seat and 40lbs. more open compared to 918's and they bind just before .700"

Sounds like they should be fine if set up properly to me. Although in this guy's case with that many miles on his 987's I would definately swap them out to new ones.

2001CamaroGuy

iTrader: (6)

so would I be ok just installing a NEW set of 987s?

Comp also makes a 985 which has the same closed pressure as the 977 but a little lighter than the 977 open. I'm trying to avoid swaping lifters if I don't need the high spring pressure.

987 set = 130lb @ 1.800" and 325lb @ 1.200"
985 set = 150lb @ 1.800" and 365lb @ 1.200"
977 set = 150lb @ 1.800" and 400lb @ 1.200"

Phil99vette

iTrader: (11)

Whats really funny is I talked to Jay 2 days ago and he said that 987s and big XER's dont mix. He said you run that big of a cam you need 977s.
Phillip

2001 Pewter WS6

iTrader: (43)

Ditto here... I have 987's with a 236/240 and it isn't enough spring pressure. How long ago did Jay tell you that? Over a month? I told him about the issue I had and he said they recently found out that the 987's were getting valve float with the G5X2.

MyLS1Hauls

iTrader: (2)

According to the Comp book, the 987s will be close to coil bind with a .600" lift cam when setup at 1.800". I'm not sure how Jay sets his springs up with 20 lbs. more on the seat. That would give you even less possible lift. Also, the only difference between a 985 and a 987 is that the 985 has a 973 inner spring with more pressure.

Louis

iTrader: (7)

We ran into float with the 987s on AS S2.5 heads 2 weeks ago.

If you are set on a dual, REVs or 977s. The new crane dual does not have enough pressure to control the valve. It has less open and closed pressure than a 987 according to their website.

If you can live with a single, the Isky 295 Ds work well with no control issues. There are a few cars with that setup, but it is $100 more. The springs are run for a 1000+ simulated miles. If any from that set break, the entire batch is tossed.

Hope that helps

JF WS6

Yeah, it was a little while ago that I asked.... Maybe he's changed his mind. I'll follow up with him and see what he says.

Are the Comp 977 springs the same diameter as the 987's? Could I just do a direct spring replacement or would I need new retainers and seats?

Smoke_ur_5.0

iTrader: (2)

It will float and isn't enough spring. Been there.

CamM

987s not enough spring pressure?!? My springs haven't shown any signs of valve float on the dyno, but I've put 2k miles on them since then. I'd like to know the definite answer on this also.

JF WS6

I'm in the exact boat as you. I haven't noticed any float either personally (would've shown on the dyno) but I also don't have many miles on mine either. So can ANYONE tell me if the 977 is a direct replacement for 987's?

SStrokerAce

iTrader: (2)

The 977's use the same retainer as the 987's, but you should install them at 1.850 height rather than the 1.800 height that the 918's and 987's are installed at.

Bret

JF WS6

Thanks for the info Bret..... so to get the 1.850 height they would need to be shimmed then? Also, going to the 977's will I have rocker arm clearance problems like some of the others have had on the Patriot heads? Thanks to anyone who can answer my questions...