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Problem with 327 build...

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Old 06-08-2014, 12:45 PM
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randymbtech
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Default Problem with 327 build...

Hey guys,

I just finished a top end build on the 327 in my '68. I installed a modified Vortec head kit from Scoggin dickey Chevy, and a Lunati Voodo 262 hydraulic flat tappet cam and lifter kit. The heads are modified by Scoggin Dickey to accept higher cam lift. I got the motor running and broke in the cam properly (I do this for a living, used the right oil and additive for break in). The motor runs excellent, but it is really noisy. It sounds like it has solid lifters and race valve train. I have set the valve lash 3 times, don't think it's a lash problem.

I just did this same exact package on my L-48 350 and it runs and sounds amazing. It has tremendous torque and pulls great. The only difference is that this is a 327, and the compression ratio is higher because the motor is a '68. The heads that I took off of the 327 are 3917291c fuelie's. According to my research, they should be 64cc just like the Vortec's I installed. Anyone have any ides why this thing sounds so loud? I must be missing something. Thanks!!!
Old 06-08-2014, 01:37 PM
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cv67
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faster ramp rates on the cam +roller rockers will bring more noise.Its good noise though
Old 06-08-2014, 02:11 PM
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doorgunner
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Rookie says-----put some miles on the engine...

maybe it just needs to be treated differently than the other engine....

oil too thin/oil pressure O.K. for the 327.....it's a great engine stock or modified!

Last edited by doorgunner; 06-08-2014 at 02:13 PM.
Old 06-08-2014, 05:52 PM
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cardo0
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Reads like u should be directing us for trouble shooting Randy. Im sure u know how to use a sthesiscope and cut open the top of a old vlv cover.

My first effort (after listening with stethoscope) would be to verify the vlv train clearances. U need to check the rocker arm clears the vlv spring retainer - for the entire vlv travel. Always verify the rocker tip wear patch is centered in vlv stem tip - side loading not allowed here. Check the rocker slot is long enough - again for the entire vlv travel so it doesnt smack the stud at the end of travel. These clearances are 0.050" to 0.060" and u need a fairly large/thick unbent paper clip to check with. The rocker arm also needs side clearance for the stud.
Grab the p-rod feel for binding in the head slot - this can usually be seen as wear marks on the p-rod also.

Last effort would be pull the intake and look at the lifters to make sure they didnt wipe a cam lobe.

cardo
Old 06-09-2014, 07:26 AM
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randymbtech
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Thanks for the help guys, I am going to get back into it tomorrow. I think I need to check the rocker arm geometry as mentioned. I used the stock push rods, as scoggin dickey told me to, but that does not mean they are right! Thanks again.
Old 06-09-2014, 07:41 AM
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MotorHead
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If you do this for a living you should know to check the valve train geometry before starting it up, I don't see how anyone can tell you that the stock pushrods are the right length. You can do this by eye with the engine in the car. You just roll it over and see that the rockers are centered properly. That's all I did on my $15,00 427ci, no need for machinst's blue or magic marker you can clearly see the if the rocker is the same on both sides of the valve stem.

Do you have screw in rocker studs or pressed in ? If pressed in then they could be pulling out.

Also check the clearance between the pushrods and the heads, the could be rubbing the heads on the inside.

Check to see if the one or two aren't hitting the valve cover or the PCV baffles.

What is your method of setting the lash, there should be zero lash.

Good luck with it
Old 06-09-2014, 08:48 AM
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Did the 327 have domed pistons? I was trying to figure out why it had more compression

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