Originally Posted by MILD THUNDER (Post 4559098)

Im not understanding clearly on the chain of events. You purchased the heads bare, assembled them, ran them, had oil pressure issues, pulled engine, then found issues with the heads? Am I understanding that correctly?

When you say you had the seats "recut" , was this before they were installed ? You earlier said the seats had to be REPLACED, was that before or after?

The 1200 dollars spent on them, was that soley in machine work?

The few friends I have that have purchased and used these heads, I strongly suggested getting them checked out and assembled by a professional cylinder head shop. Actually that goes for any brand head. There have been plenty of issues with out of the box name brand heads as well. Its no different than assembling a bottom end. You cant just order up a block from dart, and just hope the clearances/tolerances are good to go. Even a brand new dart/merlin block needs a bunch of machine work before its ready for assembly.

As far as cost, last time i looked, a pair of Dart CNC 335 MARINE heads, with inconel valves , anodizing, and assembled, was just under $5,000 a pair. And even then, i would still want to check them out before bolting them on.

Originally Posted by veloc410 (Post 4588713)

The heads were machined before install . Once you get the seats right. You won't. Have enough material left o n seats to replace guides and do touch up. Must take a close look at guides first. Just press them out and install new then do valve job. Myh guides were not true. Looked like they were cut after they were pressed in . Center hole not parallel or concentric with O.D of bushing. Just don't touch the seats unless you inspect guides first . Yes the heads perform very well, no doubt. Nice heavy castings too. They need to be gone through first thing. . My problem came after i had guide wear most likely from temperature issues . Pushed the original guides out then not enough material on seats because location changed. Had to press new seats in. So probably need new bushings right out of the box. They must remachine guides after they are pressed in . The fixture is not true to guide hole so sizing reamer is out of square to guide hole when it goes through. That is why the valves don't seat from get go. These heads will kick ass but they need machining first. Again I had valve job done first.

And last time I discuss this topic on this thread. Pete

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Originally Posted by MILD THUNDER (Post 4412828)

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.