Crane powermax 272 too big for lg4?
#2
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Re: Crane powermax 272 too big for lg4?
Probably. Not a bad cam, but will want more compression than what you have, to avoid the soggy feeling at low RPMs. It will run pretty good at higher RPM if your LG4 is modified for better breathing (exhaust above all else) but in a totally stock one it will probably feel like you have lost A BUNCH of "leave". Works better in a L69.
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Car: 1987 Z28 Camaro
Engine: 305 LG4 4bbl
Transmission: TH700R4
Re: Crane powermax 272 too big for lg4?
I can only vouch for up to .450 lift on stock heads definitively - i dont know how much more they can handle
springs and retainer replacements should be mandatory
springs and retainer replacements should be mandatory
#7
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Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10bolt 4.10 Posi w Lakewood TA Bars
Re: Crane powermax 272 too big for lg4?
That is a lot of valve lift for uncut heads, you MUST measure. Alex's parts has a kit for that without machining.
https://www.alexsparts.com/valve-spr...ssure-vsk4h50/
https://www.alexsparts.com/valve-spr...ssure-vsk4h52/
https://www.alexsparts.com/valve-spring-kit-sb-chevy-vortec-hi-perf-hyd-roller-130-lbs-seat-pressure-vsk4h53/
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87_LT (08-14-2019)
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#8
Re: Crane powermax 272 too big for lg4?
If my engine is less than 9:1 compression I'm going to skip the cam idea altogether and just start putting together a 350 shortblock. Will probably just do headers and 1.6 roller rockers until I'm ready for the swap
#10
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Re: Crane powermax 272 too big for lg4?
A good cam choice for a 8.5:1 cr supercharged 305.
A good cam for a high compression 305 10:1+
Say with improved/ported heads and headers
Can be enhanced using 1.6 intake rockers to increase intake valve lift. X 1.0666
The Edelbrock EForce supercharger does sick things to a low cr 305..
A good cam for a high compression 305 10:1+
Say with improved/ported heads and headers
Can be enhanced using 1.6 intake rockers to increase intake valve lift. X 1.0666
The Edelbrock EForce supercharger does sick things to a low cr 305..
Last edited by F-BIRD'88; 05-10-2019 at 11:04 PM.
#11
Re: Crane powermax 272 too big for lg4?
I guess I should update this thread with what I have found out about my engine since this thread started. Block casting number is 14010207 and both heads are casting number 462624 so it is most like an early 80s 350 and not an lg4. I still plan to use the crane 272-2 cam, but I have picked up a set of vortec 062 heads and a jegs vortec intake for it. Hoping it will get close to 350hp
#12
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Re: Crane powermax 272 too big for lg4?
Will work very well with vortecs.
Will need spring upgrade and valve guide boss machining for lift clearance.
Use a
.015" shim head gasket.
If the 350 has flat tops ,,bonus points.
370-375 hp. 750 carb hi rise RPM style intake
1.6's on intake only
Will need spring upgrade and valve guide boss machining for lift clearance.
Use a
.015" shim head gasket.
If the 350 has flat tops ,,bonus points.
370-375 hp. 750 carb hi rise RPM style intake
1.6's on intake only
Last edited by F-BIRD'88; 05-11-2019 at 04:06 PM.
#13
Re: Crane powermax 272 too big for lg4?
Right now I'm still on the fence between using Alex's .550 spring kit or going with beehives. From what I can tell with my little USB camera, it has normal sbc 4 eyebrow dished Pistons. From what I have calculated, the steel shim style head gaskets should bring it to right around 9.5:1 compression. For right now, i will stick with the 600cfm holley that I just put on it. Might look to upgrade that later as the budget allows.
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Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10bolt 4.10 Posi w Lakewood TA Bars
Re: Crane powermax 272 too big for lg4?
To consider the beehive springs, for starters, you have to look at the installed height and valve open pressures to see if they will work well with your cam.
Then there is the issue of fitting them into the spring pockets in the heads - machining required???
The Alex kit will get you there with NO MACHINING and waaaaay cheaper.
Then there is the issue of fitting them into the spring pockets in the heads - machining required???
The Alex kit will get you there with NO MACHINING and waaaaay cheaper.
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87_LT (08-14-2019)
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