FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: 427HISS on August 13, 2019, 09:26:35 PM
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What kind of added performance can be gained and at what apx cost ?
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It depends on which manifold and head combination. But most likely no gain. I would focus on optimizing the heads and then try to find the flow numbers for your manifold. As long as your manifold outflows your heads, leave it alone. The step up in port cross section area right at the gasket won’t hurt a bit.
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The intake is either TWM or BORLA, stacked EFI. BORLA bought TWM several years ago, so I don't which company made it, but assume it's a TWM. I'll send BORLA a photo asking who's it is.
The aluminum heads are Jim Dove's.
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Unless you have a flow number on them as stock, you are absolutely taking the risk of losing flow by making the ports larger. With such a short runner, you need the velocity, and opening them up will slow down the flow unless the heads are super efficient. BTDT, and off idle is killed when port matched, but screamed once it recovered and built some rpm. Lost torque, and was hard to drive from stop light to stop light. Joe-JDC
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By the way. That’s going to be one seriously sweet looking engine.
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Joe, I thought Port matching (including the gasket) was always a performance gain, so why do so many people do it ?
383, it should, thank you. I again painted this block the color of my body, then I have a industrial polisher to brighten the aluminum parts. It's a lot,...of sanding & buffing, but worth it at the end. I don't do it to s mirror finish though, just too much.
I thought I had pics of the new block after painting, but I guess not. The ones shown are of my last 428 FE and the non-painted is the Dove engine I bough, but I did paint it so I'll take a few pics of it, my new Tremec TKO 600 and the steel bell. I have pics somewhere...lol
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Big difference in runner length between an intake manifold, and that EFI manifold. The short port length will need all the velocity it can get to keep any torque at low rpm. Ideally you should have some idea of how much the intake flows, and how much the heads flow, and then make a decision whether to open up the intake to gasket match. Anything else can lose 20-30 lb/ft in a hurry. Joe-JDC
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I agree, flow some ports, see what you get, it may already outflow the head and having a step can help dampen reversion a little with a short runner and no plenum.
More flow isn't always better, and of course a port can flow both ways, and backwards isn't good
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What kind of added performance can be gained and at what apx cost ?
IMHO unless you are running Pro Stock, the effort has not enough return to bother. I'm making 575 HP with a 351C running a 4V Funnelweb on AFD heads. Ports line up well enough with the manifold sitting high in relation to the head port. The manifold I consider to be too valuable to grind on or mill as it's worth way more $$$ in it's original state. Making 450 on another 351C using 4V iron heads with port fillers and a 2V Funnelweb that hardly matches at all. It's not made to fit those heads, so no reason to hack on the 2V intake either.
(http://raceabilene.com/misc/351cNotes/2015/AFD4V/Fweb4V_B.jpg)
If you don't have an issue with any of the parts, then grind away - but don't get carried away. About an inch or so in either direction (heads/intake) is about all that should be needed.
LOL - the Weiand Tunnelram base lines up better BTW
(http://raceabilene.com/misc/351cNotes/2015/AFD4V/TRamB.jpg)
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I don’t think the pictures shown accurately represent his problem. This shows a mismatch in the other direction (manifold ports larger than head ports). This situation would kill power at all RPM’s and should be resolved by replacing the manifold or gasket matching the head side. Unless Power isn’t a concern.