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781 heads best mods

Old 08-05-2014, 08:15 PM
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Originally Posted by rev.ronnie
Honestly, a cylinder head set up like this benifet a greatly from higher compression (than stock) and a cam to compliment it. We have used 781 heads, with stock valve sizes and no porting and made 580+ hp with just 10.25:1 pistons and a generic Erson hydraulic flat tappet cam.

Would I put a fully reworked set of heads on a stone stock motor? Probably not worth the expense. Spending the money on pistons and a cam would net bigger results.
Ronnie, I assume that the 10.25 CR was being run on one of your street car engines - as you probably know, that high of a CR would not live for long with iron heads in a marine engine. Same with the 110* LSA - you would be relegated to running dry exhaust.
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Old 08-05-2014, 08:27 PM
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Simple.

SPAM.

====================

You can run either or both...you just have to build for it and stay on top of it. Most biz's customers would not stay on top of it.

Last edited by SB; 08-05-2014 at 08:32 PM.
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Old 08-05-2014, 08:28 PM
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I'm running 10.08:1 with iron heads, no issues.... Static compression isn't a good number to base any assumptions on as the cam, rods, and stroke dictate what your actual running (dynamic) compression is.
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Old 08-05-2014, 11:30 PM
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Originally Posted by Budman II
Ronnie, I assume that the 10.25 CR was being run on one of your street car engines - as you probably know, that high of a CR would not live for long with iron heads in a marine engine. Same with the 110* LSA - you would be relegated to running dry exhaust.
10.25:1 and a 112° LSA are fine for marine applications. Marine engines run substantially cooler than their street counterparts. Detonation is not a problem on a properly tuned engine and premium fuel. Smaller bore, long stroke engines a not as picky as one would think. The domes are very small.

As mentioned, people can wreck anything. This is the main reason we don't do retail work. Dealing with other businesses and engine shops eliminates this risk.

Last edited by rev.ronnie; 08-05-2014 at 11:32 PM.
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