Shaper

Silly question, I know but I am new to owning this truck.

Will Comp 26918-16 valve springs work on stock 91 350 TBI heads?

Also, I was wondering if anyone knows of a detailed write-up on changing out the springs with the heads still on the engine. Thanks.

Kevin91Z

iTrader: (1)

Yes, but I would get these springs:
http://www.jegs.com/i/Manley/660/22410-16/10002/-1

Along with these retainers:
http://www.jegs.com/i/Manley/660/23652-16/10002/-1

That will get you good for up to .550" lift. Dont forget to replace your valve stem seals while you're in there.

Orr89RocZ

iTrader: (20)

why do you want or need the beehives? You can get away with those above springs mentioned for most cams and i think they are alot cheaper. beehives are generally used for pretty aggressive setups

racer J

I'm actually curious about the 981-16 springs as well. Comp recommends 986-16 springs for a lot of their cams but, the 981-16 springs will handle up to a .525 lift. There is a lower spring rate on the 986-16 springs as well as them being a dual spring and having a larger diameter. The 981-16 springs will fit on factory heads though while you have to machine to get the 986-16 springs on. I understand cam math and how a cam works but, I don't understand why Comp recommends a 986-16 spring over a 981-16 spring.

Thoughts?

Orr89RocZ

iTrader: (20)

its just about spring pressure and spring life. Most of comps cams will need around 130lbs seat to work ok. higher you rev tho, with the bigger XE grinds, you will want abit more pressure to control the valves so they dont start floating.

For mild roller cams, the 981 will work ok. its got alot less seat pressure than the 986 at the advertised installed heights. At 1.700 installed height, that spring is only for .500 lift or so safely with a .050 coil bind clearance. 986 is good to .550 at its advertised 1.750" installed height.

YOu gotta match the springs to the cam for best performance

If you want a tough stock diameter spring, check out those manley springs suggested above OR talk to patriot performance for their gold and extreme gold springs. AFR also has two great 1.29 and 1.27 inch springs that should fit in stock spring pockets as well. Their 1.27 inch spring i have and its setup for near 170lbs on the seat and its good to over .600 lift its a hell of a spring

racer J

RPM is not an issue for me (crossover at 5200) but, I can see it being an issue for others. Something tells me that Patriot is expensive as are the AFR items. Speaking of AFR 170lbs seat seems high but, I'm sure it's proper for your application. It's nice to know the stock seats have options though for springs.


Those Manley valve springs look like a hell of a buy. 130# of seat pressure vs the 105# seat pressure of the 981-16 springs for the same price range is hard to ignore. Plus they are in the same spring pressure range as the 986-16 springs and have a bit more open seat pressure. They also don't require any head mods to go on. After looking into the Manley springs, they make the 981-16 springs look like junk and the 986-16 springs as not worth the time and cost.

Shaper

I was looking at the beehive springs, for two reasons. I had great results with them on my heads/cam LS1. I like the engineering behind the ovate springs, smaller retainers(steel ones are lighter than most regular sized titanium ones) and the supposed more efficient "beehive" shape.

I plan on going with EQ 180 heads soon, but I have to change out my springs now anyway, so I figured I would go ahead and upgrade now. Looking at the comp springs again I might need to go with the 986's to match my new cam which will be custom ground (as much lift I can get away with without flycutting) after the heads are installed.

Those manley's do sound nice and have some nice specs. Do you know how much each spring weighs including the retainer?

Orr89RocZ

iTrader: (20)

patriot set comes complete for 250 bucks or so. the upgraded extreme gold spring is 279 for the set. This is a good deal, it includes titanium retainers, viton rubber intake/exhaust valve seals, machined spring bases, and locks. Designed for LSx guys and their 8mm valves so you wil need to buy a set of regular valve locks for small block chevys but those are cheap. The valve seals are for 8mm as well so you'll need new ones of those. BUT you could upgrade to the 8mm valve stem valves anyway as they are much lighter, but not worth it on stock heads i guess.

You can get the springs themselves for 150 bucks a set, some places cheaper i bet.

AFR i'm not sure, the good 8019 spring is a 100 dollar upgrade over the base 1.29" 8017 spring. I'd have to look to see their pricing if advertised on teh site.

And yes my springs are setup very stiff, 166lbs intake, 170 exhaust i think it is. My custom cam grinder told me this would be very good for the cam he spec'd for me and the revs i plan to hit (6500), so i set them up to those specs



The manleys are nice springs tho, a very stiff single spring. being a 1.25 inch spring they probly weigh as much as stock and thats not that much. Thats good. They have the pressures to handle most comp/crane cams as long as revs are under 6000. For a higher lift cam with some aggressive ramps, i'd go to a dual spring with more pressure or the beehives.

If you plan on running a aggressive cam later with loads of lift, then get a good spring like the patriot extreme gold springs or the big beehives from manley that have more pressure than comp's version. OR the PAC1518's which are a beehive with 650 lift handling capacity. MORE than likely you will get away with near .600 lift on a hydraulic roller. Not to many cams are bigger than that nor do they need to be as most heads are done by .600 anyway. Talk to the custom cam grinder to see what they recommend. They grind cams to the springs you intend to use sometimes, instead of just grinding the cam and telling you what springs you need to run. Thats important to know to make sure you get the best cam for your setup. SO if you buy the springs now they need to know if you intend to reuse them.

Shaper

It will be around .58x-.59x on either side I figure depending on the quench of the new heads and gasket thickness. It will certainly have agressive ramps, the intake being steeper than the exaust side. The LSA and overlap are TBA.

I couldnt find Manely's version of the beehive on Sumit. Do you know a vendor that has prices on them?

Orr89RocZ

iTrader: (20)

http://store.summitracing.com/partde...5&autoview=sku

well thats the manley conical ovate wire spring, also called a beehive spring. kinda pricey but they have more pressure than the beehive comp has. Its got 150lbs on the seat at rated installed height

The other bigger beehive is the pac springs. 1518 is their special coated beehive that allows more lift than their base beehive. 1218 is similar to comps 918 spring as PAC used to make it for comp, and its good to .600 lift. The 1518 is good for .650. Both are rated at same 130lbs on the seat at the same installed height, but if you shim up the 1518 .050" and run max lift of .600, then your seat pressure will be 145lbs, so its not a bad spring either.

Beehives you can run less pressure and be ok. My custom cam is .603/.613 lift on a small base circle. I'm running AFR 8019 dual springs setup for 166-170lbs on the seat. SLight overkill, as i could have gotten away with 158-160 or so. He recommended beehives in the 140lb range for this cam even tho comps 130 may have worked just fine.

racer J

Yea, I won't venture beyond a .510 lift unless it's on a LSx based engine. Please keep in mind 6000 RPM would be the DEFINITE cutoff on a Gen I SBC for me so I think the Manley springs from Kevin's post would have more than enough pressure given that criteria. Define aggressive ramps though because, everyone has their own opinion on what is mild and what is wild.

Orr89RocZ

iTrader: (20)

eh the XE series from comp are pretty aggressive for hydraulic rollers. Cams like the LT4 hotcam, zz4 cam, or computer controlled series like the cc306/cc305, those are pretty lazy ramps.

My cam isnt that much more aggressive ramp wise than the cc306, just abit more aggressive but it has a LOT more lift and different valve events, tighter lsa, so its gonna rev up and need high springs mainly because of all the lifter travel.

LSx cams are pretty aggressive lobes, and my spring setup has been proven by those guys. I got the same pressures they run on some of their 6500+rpm cams

Nothing wrong with more than .510 lift on gen I's, as long as your heads will flow there.
What cam/heads are you considering? If your under 220 degrees duration, under .525 lift or so and dont wanna rev much over 5500, then yes the manleys will work great. I was planning on camming my stock L98 once and was gonna run the 503/276 grind from comp, the 224/230 XE grind very nice cam and i was gonna use the manleys for my stock heads

racer J

That's actually the cam I'm looking at. Well the LT1 version anyway as I can get it cheaper than the Gen I version. Probably going to use the RHS Vortecs with it but, I may just use the 187 L03 heads right now. The 187s were the reason I was asking about the springs as the RHS heads SHOULD already be able to handle that grind. Yes I know, the 187 heads are crap. It's more of seeing what those heads are capable of with this cam and moving up to the RHS Vortecs later on.

Orr89RocZ

iTrader: (20)

Then you probly will be ok with the manleys, although bigger/stronger dual springs wouldnt be a bad choice if you can get them

racer J

I'll go with the Manleys right now then. I just don't see the need of having 187s machined to take larger springs. It's not cost effective especially since the 187s will NEVER see past 5200 and since the RHS Vortecs already come with springs.

Kevin91Z

iTrader: (1)

Its not in the catalog but I can weigh one for you when I get to work in the morning. Steel retainer and titanium, with spring. I wont be able to post it until after work, though.

Yes those are our "beehive" springs. They're more expensive because they're the "Nextek" design with better material. Unfortunately we only make an 11/32" retainer in titanium, not steel. They're made for LS1 with 5/16" valves. But you can use the Comp steel retainer for their "beehive" springs on our Manley springs as its the same diameter. Allen (1989TransAmGTA) is running the Manley springs in his engine right now. His Comp springs started at 130lbs on the seat but were down to 100lbs after only a year.

Kevin91Z

iTrader: (1)

All weights in grams.

22410-1 spring - 82.5g

23651-1 steel retainer - 21g

23652-1 steel retainer +.050" lift - 20.5g

23642-1 titanium retainer +.050" lift - 9g

------------

221428-1 "beehive" spring - 78.5g

23625-1 titanium retainer +.050" lift for LS1 valves - 5g

23626-1 titanium retainer +.050" lift for SBC valves - 6g

Shaper

Wow, thanks for those specs. I knew there was a big weight difference, but not near 4 oz for the set.