INTERNAL ENGINE MODIFICATIONS Valvetrain |Heads | Strokers | Design | Assembly

Cam and L92's

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Old Feb 20, 2011 | 01:18 PM
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Default Cam and L92's

So I fear I may have made a mistake. Hoping someone can help me understand the madness.
I ordered an EPS tt3 for 4.8-5.3 cathedral port heads. I'll put it in my 5.3 and I later want to put this same cam in my 408 with L92 heads.
Can I even do that?

From what I've been reading there may be PTV clearance issues if not using a cam that is designed for L92 heads. What makes the l92 require a different cam?
am I going to need to order a new cam when I'm done with my build?

The 408 will likely have -15cc dish pistons with L92 heads and the cam spec on the tt3 is 224/230 609/607 111.

any info on this whole head n cam requirement is wanted. Don't I even need to make sure i'm ordering pistons for L92 heads?
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Old Feb 20, 2011 | 01:39 PM
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Most of the time the poor exhaust flow of the heads is the reason for there own cams. Cans help you on the ptv question tho
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Old Feb 20, 2011 | 02:09 PM
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Originally Posted by viciousknid
So I fear I may have made a mistake. Hoping someone can help me understand the madness.
I ordered an EPS tt3 for 4.8-5.3 cathedral port heads. I'll put it in my 5.3 and I later want to put this same cam in my 408 with L92 heads.
Can I even do that?

From what I've been reading there may be PTV clearance issues if not using a cam that is designed for L92 heads. What makes the l92 require a different cam?
am I going to need to order a new cam when I'm done with my build?

The 408 will likely have -15cc dish pistons with L92 heads and the cam spec on the tt3 is 224/230 609/607 111.

any info on this whole head n cam requirement is wanted. Don't I even need to make sure i'm ordering pistons for L92 heads?
theres no special cams for l92 heads, i ran a 232/238/612/607/112 +2 advertised 230/238 and a 235/239/624/624/113+1 BUT on a LQ9 shortblock. these are NA spec'd cams


if you dont mind me asking what are you after in your setup ?
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Old Feb 20, 2011 | 06:31 PM
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Shooting for 450-500rhp on the 408 with l92s milled 30, ls3 car intake, -15cc dish pistons. Somewhere around 10.1:1 with the ability to do heads n cam swap in the future for turbo. Goin to a stock l92 should brin it back down to 9.6:1
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Old Feb 20, 2011 | 06:32 PM
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The stroke should take care of any tq I need but want it to scream up top
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Old Feb 20, 2011 | 06:38 PM
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You need to look at the DCR with that cam and your 408 engine specs...
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Old Feb 20, 2011 | 08:26 PM
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Dcr?.?
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Old Feb 20, 2011 | 08:30 PM
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he may have meant SCR static compression ratio instead of dynamic compression ratio, you wanna keep your DCR above 8.00 or it will feel like a dead dog leaving on launch

Last edited by skeet; Feb 20, 2011 at 09:10 PM.
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Old Feb 20, 2011 | 08:35 PM
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Dynamic Compression Ratio. Google it and look for a calculator... plug in the numbers for your 408 and that cam and post up what it comes back with... IMO anything over 8.5-8.6 is toooo much...


http://search.yahoo.com/search;_ylt=...8&fr=yfp-t-701
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Old Feb 20, 2011 | 08:43 PM
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Originally Posted by viciousknid
Dcr?.?
yes sir, DCR so you can keep it pump gas friendly. If my calculator is right, with a .060 head gasket, 4.30 bore, 4" stroke, adv -.006 out of the hole, 64cc chamber, and -15 dish piston it comes to a 8.06 DCR. As long as the cam has no advance. At 111+4 it is around 8.32 DCR. I say go for it, stick with a stock H/G. DCR should be around 8.5 like Corey said....
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