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Engine Quest Head work results

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Engine Quest Head work results

Old 03-07-2016, 08:05 PM
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Default Engine Quest Head work results

I know some of you were interested in the Engine Quest heads, so, I'll share what I have found so far.

Good castings out of the box, which I had mentioned in the other thread that got shut down. One of the main reasons I bought these heads, was their low initial cost, which would allow me to have a cylinder head specialist, spend some time on them setting them up for my engines. What guide clearances I wanted, what springs, spring setups, what valves, and so on. Having read a ton about them over on Yellowbullet, and Speedtalk, and a few other forums, the consensus seemed to be, that they are a good head out of the box, but a really nice head, if you spend some time working on them. My cylinder head guy, hadn't used these heads yet, so he was interested in seeing how they performed out of the box. Once he saw the out of the box flow numbers, he got really curious to see what some work would do for them. I pretty much told him, "do what you do, and give me the bill". His thoughts were, lets do a really nice valve job, blend things in, port the chambers, adjust the throat diameters, and go from there. Which he did. He flowed them, and while the results were still very good after all that, he felt the exhaust flow could have been improved a little, so he went into the exhaust bowls a bit, and saw some measurable gains. Anyhow, here's where we are for flow numbers. Mind you, intake ports are pretty much untouched at this point, other then the throat. I think we are going to call them good and assemble.

My prior heads were the 308 Darts, and were flowed on the same bench, same fixture, as the EQ heads, and the 345 Iron Eagles (icdedppl's heads). I havent totaled up what I have in them so far, but obviously cylinder head guys don't work for free, especially when it comes to working with iron. When I get some times, I will tally up my costs per pair when ready to bolt on. I think these would make a really nice head for those running saltwater. Heck, even freshwater took its toll on my old aluminum darts. These are the 320cc versions. Also avail in 360cc. FWIW, my darts were originally 308 heads, but had a little work, and actually measured 319cc at the port. The Darts made 804HP at 6200 on my 468's with 7psi boost. I plan to redyno with new heads.
Attached Thumbnails Engine Quest Head work results-hiflowtests.jpg   Engine Quest Head work results-20160229_161245.jpg   Engine Quest Head work results-20160229_161318.jpg  


Last edited by MILD THUNDER; 03-07-2016 at 08:09 PM.
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Old 03-07-2016, 08:43 PM
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Those are good numbers. Back cut on the intake makes a huge difference in low lift numbers. I have a new set of EQ 320's here that I'm doing a valve job and blower marine prep. Staying with the 2.25 valve and not doing any porting. I may throw them on the flow bench just to see how they compare.
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Old 03-07-2016, 08:45 PM
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They did great especially on the lower lift. I cleaned the chambers on my 308 irons real carefully and to me they look like a cnc dart chamber I looked at (I'm not saying it's as good but close). I left the intake port alone, but back cut the ferrea valves 30 degrees. I did clean up the exhaust port and I'm running ferrea tuliped super alloys untouched. I'm at .63 lift. What is your total lift?
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Old 03-07-2016, 08:48 PM
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I'm no head expert but I am happy with the looks of the heads i bought. The numbers definitely kill stock rec ports which is what I replaced. I'm looking forward to see how they run. I think they are going to be hard to beat for the money.
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Old 03-07-2016, 08:51 PM
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Originally Posted by Mr Maine View Post
They did great especially on the lower lift. I cleaned the chambers on my 308 irons real carefully and to me they look like a cnc dart chamber I looked at (I'm not saying it's as good but close). I left the intake port alone, but back cut the ferrea valves 30 degrees. I did clean up the exhaust port and I'm running ferrea tuliped super alloys untouched. I'm at .63 lift. What is your total lift?
Same thing, .630 lift. Hopefully within the next year or two, I can build some bigger shortblocks when these wear out, and then move on to a higher lift cam.
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Old 03-07-2016, 08:54 PM
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90% of the improvement you can make on a set of heads occurs within 1" either side of the valve job.
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Old 03-07-2016, 08:58 PM
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Originally Posted by horsepower1 View Post
Those are good numbers. Back cut on the intake makes a huge difference in low lift numbers. I have a new set of EQ 320's here that I'm doing a valve job and blower marine prep. Staying with the 2.25 valve and not doing any porting. I may throw them on the flow bench just to see how they compare.
Scott, would there be any reason NOT to back cut an intake valve? Reason I ask, is my old valves did not have a back cut.

He flowed them stock with the tulip ex valve and nail head valve, I forget the difference in flow, wanna say around a 8-10 cfm gain on the exhaust from the tulip ferrea over the manley. That sound about right?
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Old 03-07-2016, 09:10 PM
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Most intake valves don't come with a back cut so that's the way they usually stay. No reason not to back cut. It's always an improvement.
I don't get too carried away with ex flow numbers. You can ruin an ex port and cost a bunch of power by trying to chase flow numbers. Tulip ex valves seem to always flow better but not always the best choice. Unfortunately most of the extreme alloy valves seem to come with a semi tulip shape. I think they're just trying to get as much material in a critical area as they can but they sure are heavy.
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Old 03-07-2016, 09:14 PM
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Heres a flow sheet I found somewhere online. Apparently fully ported.

My guy did mention the exhaust port "sounded" good, for whatever thats worth.
Attached Thumbnails Engine Quest Head work results-fb_img_1453439817558.jpg  
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Old 03-07-2016, 09:23 PM
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Originally Posted by MILD THUNDER View Post
Heres a flow sheet I found somewhere online. Apparently fully ported.

My guy did mention the exhaust port "sounded" good, for whatever thats worth.
Joe Petelle is one sharp dude.
Sound means a lot.
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