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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Hey guys. I'm doing a cheap/budget build on my LG4 until I can afford a 350 or larger engine. I want the work I do to it to transfer over to that new motor should I end up getting one. How much lift can I put on the stock 416 heads? I've done research and can't find a definitive answer. My best guess based on my research is no more than .450". Can any one give an educated opinion on the heads and their lift capacities? Also, if I do need to work them to go past that, what would I need to have done to them.
Also I already have an Edelbrock Performer intake and Holley 600 carb that I had on the car already. I am doing exhaust towards the end of the month with headers and new back from there.
Hey guys. I'm doing a cheap/budget build on my LG4 until I can afford a 350 or larger engine. I want the work I do to it to transfer over to that new motor should I end up getting one. How much lift can I put on the stock 416 heads? I've done research and can't find a definitive answer. My best guess based on my research is no more than .450". Can any one give an educated opinion on the heads and their lift capacities? Also, if I do need to work them to go past that, what would I need to have done to them.
Also I already have an Edelbrock Performer intake and Holley 600 carb that I had on the car already. I am doing exhaust towards the end of the month with headers and new back from there.
Not exactly the same casting, but should be very similar, I ran 081s at .460" lift with no modifications and ran a set of 601s at .465".
I had an Lg4 with stock heads and used a cam with around 455-465 lift I cant exactly remember but had no issues. Had a good intake, Holley DP, and headers w/3in exhaust. It turned 14.88 1/4mi. My stock LB9 I bought a few yrs later was actually a tad faster to my surprise.
Thanks for the input. Much appreciated. Now I know I can use the cam I had in mind. I also have a set of 1.7 roller rockers laying around. Can I utilize those?
I just put a lunati cam in my LG4, home ported the heads and the difference was night and day from stock even with having stock manifolds yet. Specs are in my sig. Haven't had it to the track yet.
http://www.competitionproducts.com/mobile/Elgin-Hydraulic-Flat-Tappet-Complete-Cam-Kit-Chev-SB-214_224-288_298-443_465-112-LC/productinfo/E922K/#.VEnBR3Mo7qA this is the cam I want to use. Comes with everything I would need for a good price and have heard good things about Elgin. Should I go ahead and pull the heads to swap springs or will stock springs work? And would 1.6 rockers be of any benefit?
On most stock heads of that era the bottoms of the retainers will touch the tops of the guide seals around .470" of valve lift.
Even if you are under that, stock springs are not adequate to control the valves at higher RPMs with an aftermarket/performance cam.
A set of Comp 981 springs or cheap eBay "Z28" springs are good "drop-in" upgrades for stock and will work fine with most mild flat tappet cams, as long as your lift still doesn't exceed the retainer-to-guide seal limitations of the stock heads.
http://www.competitionproducts.com/mobile/Elgin-Hydraulic-Flat-Tappet-Complete-Cam-Kit-Chev-SB-214_224-288_298-443_465-112-LC/productinfo/E922K/#.VEnBR3Mo7qA this is the cam I want to use. Comes with everything I would need for a good price and have heard good things about Elgin. Should I go ahead and pull the heads to swap springs or will stock springs work? And would 1.6 rockers be of any benefit?
That is a really lazy cam grind IMO.
I think you would be much happier spending a little more coin and getting a much better product. I feel this small Isky cam would blow the cam above away in terms of power and overall driveablity. With the 108* LSA it would sound a little better at idle as well. I really don't feel the stock 305 heads flow enough upstairs to effectively use 1.6:1 rockers with more than .450" valve lift. Full roller 1.5 or 1.52 rockers would be a nice upgrade from the factory stamped steel that vary from 1.42 to 1.48:1 through their sweep and create extra heat from friction. I would run this cam advanced 4* to a 104* ICL. With the 4* advance in a 305 it would make power from about 1,600-5,600 rpm in the 305.
With 1.52:1 rockers it would end up about .456/.456" valve lift and IMO a great match for a stock 416 head.
Granted with the kit above you won't get the springs or locks and it cost more, if you want it to run well, its worth spending the extra money. A decent set of small block valve springs, retainers, and locks can be had fairly inexpensively anyway and the valve seals come with the head gasket set.
With the slow valve timing of that Elgin cam even 4* advanced the intake valve doesn't close until 72* ABDC blowing a substantial amount of intake charge back into the intake at lower rpm and the exhuast valve starts to open at 85* BBDC. With the quicker Isky ramps and shorter exhaust duration the intake valve is closed 16* earlier by 56* ABDC trapping more cylinder pressure and the exhaust doesn't open until 64* BBDC giving the still expanding combustion gases an additional 21* of crank rotation to push the piston down. The Isky cam also has substantially less overlap at 48* compared to the 69* of the Elgin cam.
Your 86 LG4 should have flat top pistons in it, if it is factory. They will be about .025" down the hole. I would consider using Felpro 1094 head gaskets. That would bump you from 9.5 to 9.7:1 static and the Isky cam 4* advance would give you 8.25:1 dynamic compression. Perfect for iron heads on pump gas.
I think you would be much happier spending a little more coin and getting a much better product. I feel this small Isky cam would blow the cam above away in terms of power and overall driveablity. With the 108* LSA it would sound a little better at idle as well. I really don't feel the stock 305 heads flow enough upstairs to effectively use 1.6:1 rockers with more than .450" valve lift. Full roller 1.5 or 1.52 rockers would be a nice upgrade from the factory stamped steel that vary from 1.42 to 1.48:1 through their sweep and create extra heat from friction. I would run this cam advanced 4* to a 104* ICL. With the 4* advance in a 305 it would make power from about 1,600-5,600 rpm in the 305.
With 1.52:1 rockers it would end up about .456/.456" valve lift and IMO a great match for a stock 416 head.
Granted with the kit above you won't get the springs or locks and it cost more, if you want it to run well, its worth spending the extra money. A decent set of small block valve springs, retainers, and locks can be had fairly inexpensively anyway and the valve seals come with the head gasket set.
With the slow valve timing of that Elgin cam even 4* advanced the intake valve doesn't close until 72* ABDC blowing a substantial amount of intake charge back into the intake at lower rpm and the exhuast valve starts to open at 85* BBDC. With the quicker Isky ramps and shorter exhaust duration the intake valve is closed 16* earlier by 56* ABDC trapping more cylinder pressure and the exhaust doesn't open until 64* BBDC giving the still expanding combustion gases an additional 21* of crank rotation to push the piston down. The Isky cam also has substantially less overlap at 48* compared to the 69* of the Elgin cam.
Your 86 LG4 should have flat top pistons in it, if it is factory. They will be about .025" down the hole. I would consider using Felpro 1094 head gaskets. That would bump you from 9.5 to 9.7:1 static and the Isky cam 4* advance would give you 8.25:1 dynamic compression. Perfect for iron heads on pump gas.
Wow okay thanks for the good info. I will definitely look in to it!
hi
sorry for upping this topic
i searching in google for my question then i found this topic
my primary question is topic name
how much is maximum valve lift for 416 and 081 heads
in my opinion 0.475 but i'm not sure
next question
how much lift support the factory std valve springs on these heads ?
in really when we talking about lift capacities of heads the valve springs determines cams lift not heads is this true ?
so at the end i want to use edelbrock 2209 cams on my engine (305 1987 caprice) but i dont know can i or i cant
but also i had been requested from edelbrock and they said to me :
for the Roillin' Thunder Hydraulic roller camshaft 2209 Edelbrock suggests 125-150 lbs. on the seat with350-375 open pressure
meaning i should to buy 2209 with comp cams 981-16 if i use 2209 but without changing valve springs this setup have a problem ?
Originally Posted by Damon
On most stock heads of that era the bottoms of the retainers will touch the tops of the guide seals around .470" of valve lift.
Even if you are under that, stock springs are not adequate to control the valves at higher RPMs with an aftermarket/performance cam.
A set of Comp 981 springs or cheap eBay "Z28" springs are good "drop-in" upgrades for stock and will work fine with most mild flat tappet cams, as long as your lift still doesn't exceed the retainer-to-guide seal limitations of the stock heads.
well going to this post
std 416 - 081 retainers will make a problem with high lift so should i buy valve springs with retainers ?
this is true but higher than how much ? 5k rpm or ?
how much the retainer-to-guide seal limitations of std heads ?
No one can give you an exact number as to whether your combination of parts will have clearance issues, or not.
The bottom line is that YOU HAVE TO MEASURE.
Our Vortec kits are specially engineered for Iron Vortec & 96 iron LT1 Impala heads. The parts go on without the need to machine anything.
That's right, no machine work required to set up a pair of iron Vortec heads.
We engineered this kit with all the right parts so Vortec head owners won't need to take them to a machine shop.
Works with stock or with most aftermarket self aligning rockers.
Its common knowledge Vortec heads have a problem w/ retainer to seal clearance. The stock retainers and springs do not allow for more then around .460" lift.
This kit is specially engineered to allow for up to .550" lift using our custom designed retainers, springs & locks.
Our Vortec kits solve two common problems on these heads:
The retainer to seal clearance issue. And the spring base diameter issue (Vortec heads will not accept common SBC springs).
Call Alex and you can talk directly to him. Explain what you are trying to do. He is a great guy and can deliver what you need.
i found this info :
Since we wanted to run a mild camshaft that would generate almost a half inch of lift, we knew we would have to modify the Vortec heads. The stock Vortec’s Achilles heel is that the valvespring/retainer/seal combination is limited to a maximum of about 0.460 inch of valve lift.
omg when i read post #12
i just read to last link and i forgot to read more !!!
now i see "Our Vortec kits are specially ........."
is this kit compatible with swirl port 081 - 416 cast number heads ? or just compatible with 96 and later vortec heads ?
and follow to that specs : Specifications:
Outside Diameter- 1.270"
Inside Diameter- .880"
130 Lbs @ 1.790"
340 Lbs @ .550" lift
Rate- 365
Average Coil Bind 1.150"
Beehive Spring? - No
High Perf Replacement Spring? -Yes
i think these springs incompatible with vortec heads guide boss because Inside Diameter springs from this kit is 0.880 and vortec heads guide boss diameter is 0.900 so with this springs we have not clearance !!!!
is this true ?
04-06-2015 | 10:42 AM
