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Old 10-07-17, 01:05PM   #1
Mr.Pontiac
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Default maybe just maybe thinking of cam change?? ideas

I love my set-up so far but i am thinking about a cam change to a flat tappet instead of my Hydraulic Crower. 60243. Who should i talk to???
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Old 10-07-17, 02:49PM   #2
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NOT NEEDED. give Cliff a call to confirm what I said about it needs 4 deg advanced. OR JUST DEGREE THE CAM. The cam you have now will get you into 11.70 or better.
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Old 10-07-17, 03:01PM   #3
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Here you go Comp Cams ??1 (800) 365-9145‬. Make sure you tell him what your running for compression.

I know what I would do but Iím not getting involved.
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Old 10-07-17, 03:18PM   #4
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Quote:
Originally Posted by thomas flaherty View Post
NOT NEEDED. give Cliff a call to confirm what I said about it needs 4 deg advanced. OR JUST DEGREE THE CAM. The cam you have now will get you into 11.70 or better.
I have to disagree with you his biggest hurdle is the compression heís running.
9.5 on a 400 with aluminum heads is like 8.50. Aluminum head takes at least 1 point more compression. Over a iron head. He should be running a minimum of 10.75. Easy .1 tenth. Then Iíd go with something like 236.246 duration cam with .550 lift on a 108-109 c

Cam heís running is only 228-235 on 112 with .479 lift with his 1.65 rocker itís like 5.29 lift. Itís basically a Ram 1V can
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Old 10-07-17, 03:28PM   #5
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A Ram 1V Stock from the factory had 10.75 compression. Heís Basically running same cam.
With his head itís more like 8.50. Ram 4 What those heads flow 195-220 CFM. E-head 270-280 out of the box.

Under camed and under compression, but he did damn well for what heís running,
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Old 10-07-17, 04:14PM   #6
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040 over 400 cid zero decked .039 felpro gasket 72 cc heads. I'm not going to do the math but it not 9.5 or 8.5. Back in the day that was 10.50 -10.75.
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Old 10-07-17, 05:39PM   #7
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great answers thanks guys!! honestly i am not up on compression, but with my 4 valve reliefs in my pistons it may be hurting me.
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Old 10-07-17, 05:52PM   #8
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Just asking ok, i am just asking, best way to up compression mill heads??? Gach, don,t get involed but if it was you???
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Old 10-07-17, 06:36PM   #9
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Fix your heads
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Old 10-07-17, 07:56PM   #10
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Compression and the application involved, street engine with some racing or all out racing to push the compression envelope. An opinion for conversation.....

Many years ago when I was planning a previous 462 build with Edelbrock aluminium cylinder heads I contacted Dave Bisschop about compression ratios. At the time based on his dyno testing he was recommending a maximum of 10.25 compression with the 87cc Edelbrock chamber design as cast and 10.5 compression with the 72cc Edelbrock chamber design as cast. This was a general recommendation for engines leaving his shop to be used under all types of driving conditions, unknown gas quality, unknown camshaft parameters, and not knowing how the end customer would tune and operate the combination. Obviously under the right conditions it could be higher but like many professional engine builders they are not going to suggest pushing it for most people with a lot of unknowns.

Keep in mind this statement, "The design of the combustion chamber influences the performance of the engine and its anti-knock properties. The layout and shape of the combustion chamber has a bearing on the thermal efficiency and performance as well." If it's the newer design Edelbrock chamber it's a different story.

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Old 10-07-17, 08:30PM   #11
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please, i beg you, fix your heads when there,s nothing wrong with them, set up to original specs.Correct installed height, correct springs & all. See why i am asking??
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Old 10-07-17, 08:57PM   #12
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Two cylinders leaking air on the leakdown. Confirmed with lower compression test's . Your words I have to talk to the 3rd machinists Question are you still planing a new short block this off season.
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Old 10-07-17, 08:57PM   #13
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And what is the actual verified installed height on the heads ? And what are the valve springs in use with their rated specs ? And what is the actual verified spring pressure, not when installed but after use, after they have dropped some pressure ?

At one time Crower called for 116 lbs seat pressure with the 60243 cam. Probably the same today.

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Old 10-07-17, 09:04PM   #14
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In a other thread me and Steve asked about the brand and part number of the valve springs PS a other question are you going to try again before the end of the season to see if your top end problem is fixed.
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Old 10-07-17, 09:16PM   #15
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I also previously asked him direct as to what cam he was using. No answer. Only now I'm I seeing it posted. That said, it might of been posted a month ago, or longer, but I didn't want to wade thru hundreds of posts to find it


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