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Old 02-15-2017, 04:31 PM   #1
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My 5.7 needs a cam

I have come to the conclusion that my G30 needs a new cam/lifters. Does anybody have any suggestions for the right cam?part#? Fuel economy and cost our primary concerns and towing secondary. I'm pretty sure the turbo 400 transmission and 410 geared rear would tow great with just a stock Truck cam.

I'll be throwing on a new timing chain and water pump at the same time. Just for safety sake

Jeep, bus, repeat.
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Old 02-15-2017, 06:08 PM   #2
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I am assuming you are talking about a 5.7L/350 small block.

If you are, the upgraded RV cam would be ideal for your purposes.

If you don't have it already upgrading to EFI would be a great idea. Fuel mileage may get a little bit better but the driveability will be greatly enhanced.

Opening the exhaust up and getting a cold air induction system installed will go a long way towards improving the burn in order to take advantage of the improved cam profile.
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Old 02-15-2017, 06:14 PM   #3
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+1 on an RV cam... what yeasr is that? is it later than 87?

the chevy 350 in 87 started shipping with Roller cam and roller lifters. thats adds to the cost of things and gives you a bit fewer choices,..

86 and older engines have flat tappet cams and lifters which drops the cost and offers many choices..
-Christopher
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Old 02-15-2017, 06:59 PM   #4
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Its an 85

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Old 02-15-2017, 07:38 PM   #5
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also you need to know what the engine speed is at the normal speed you travel, you want a cam optimized for that engine speed for best power and economy
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Old 02-15-2017, 07:56 PM   #6
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did you wpe a lobe on the original? or just trying to beef it up a bit?

do you have an idea of what your preferred cruising RPM is? I rememebr you have a TH-400 trans (1:1) but cant remember what rear and tires you have...

we cant go with anything too wild as the stall speed on the converter is likely 1400-1800 on that bus..


I have used the comp cams in the past with good success..

COMP Cams: Dual Energy™ 255DEH; Hyd. Flat Tappet; '58-'02 Chevy Small Block

this one is a smooth idle.. gives good low end torque but will not be as aggressive in power at the higher RPM (above 4000)...

they make a 265 which is a bit more aggressive but also creates a bit more rough idle... rough idle sounds bad-ass but can be cumbersome if the torque converter stall is too low..

-Christopher
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Old 02-15-2017, 08:17 PM   #7
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My cruising rpm is in the 2500-3000 range. I think 2700 is about 60. Rear is 4.10 gears. Th400 is 1:1 tires are 215/85r16.

One of my cyl isnt firing. Rocker arm is barely moving. Compression is great across all the cyl. Holds pressure too.

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Old 02-15-2017, 08:32 PM   #8
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wiped Lobes are common in older engines with modern oils... flat-tappet cams dont like the new oils...

I ran a product called ZDDP-PLUS in my old hotrods for this very reason... I may still have some of the stuff in my garage in ohio...

you may also just have a flat lifter... the first step would be to yank the intake manifold and examine the lifter for the affected rocker... on a 350 they can be plucked from their bores with the heads on.. is there excessive play in the pushrod for that valve?

when you get the lifter out you can use a micro camera to examine the cam lobe visually.. and of course the bottom of the lifter...

if the lifter is a ^&*%^&* to get out of the bore it usually means the cam ate up its base...

pullinfg the intake also lets you make sure thats the original bloick and someone didnt stuff an 87 or later block (with roller lifters) in..
-Christopher
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Old 02-15-2017, 08:44 PM   #9
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Could very well be a flattened cam lobe, I'd recommend converting to a roller cam and lifters for durability alone. It wouldn't be cheap, but with the lack of ZDDP in today's oils it would mean only having to do the job once.
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Old 02-15-2017, 08:58 PM   #10
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Theres no tapping or noise. If it is the original thirty-year-old lifters and Cam I really don't mind replacing it before we go all the way to California from Florida. If I convert from Flat to Roller do I need new pushrods?

Jeep, bus, repeat.
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