This has to be the best series on big block chevy building out there. Really amazed how little you have touched the port compared to the results in flow.
Mark thank you for doing this series on this head. This is hands down the best video ever on any head porting, valve job, etc. You sir are a true master machinist. I wished your shop was close to me, I would be working for you!
The details in these videos are amazing. Watching this series is like getting a free college degree in porting an engine. Thank you for taking the time in explaining, demonstrating, and showing the results of the work.
This is one of the best vids I've ever seen on porting including many by David Vizard. It isn't BS for customers who want 'pretty' but is showing what actually works even if port looks ugly. What's most impressive is your not leaving out or editing the critical parts as many do to hide stuff for later sales, instead pointing out in detail where things need work to actually help people on a budget (although tuning any V-8 is never going to be cheap)
I am using this and other info experimenting with my old Harley Sportster heads. They are cast iron with HUGE ports and valves. I bought a junk set to section cut, as a retired draftsman cutting sections on paper is what I did. I even made my own flow bench contraption, some old guys golf. I drag race old motorcycles...
I enjoy watching all your videos, you are very meticulous and you know your stuff! No guesswork here.... I learned a lot and was surprised how many details are taken into account when building an engine..... now I know what's the meaning of a blueprinted engine! Thumbs up 👍 👌
Really great series to watch! really digging this tutorial on the heads. I.m going to be starting on a set of 215's. I'm hoping the valves aren't to shrouded with the smaller chamber, but then I'm only looking to make somewhere in the neighborhood of 500 hp. Thanks much for doing this series.
I saw your list of costs and you listed the castings at $100. I wish I could decent heads of any kind. All rusty junk and pricey. I'm building a 99 Gen 6. Absolutey no rust or minerals in the water jacket and the block is high nickel and factory roller. I was told for the money I'd spend for the hp that out of the box Race Rites are better plus lighter. 650 with cast crank and rods is impressive. Great work!
Might not look like a lot of material removal but trust me even with the best carbides it takes a lot time a patience, a job like this could cost u well over a grand, just on the port work
Mark is right, put an intake gasket on the parts to check for core shift. I got these a long time ago and they were already machined, then this series comes along and I find out today that I have core shift! What ya going to do! I had to hog the hell out of the left side of each intake port. I’m sure I got all of .100 off that side. Three hours just to do four intake ports the first 2 1/2-3 inches. Will be using the 6” SE6 tomorrow the rest of the way. Then the bowls. I figure I’ll have 10-12 hours just to finish the intake runners of both heads. I’ve done about a dozen sbc heads. Those take up to 16 all done.
How much horsepower do you think a set of these heads can make in stock form? I've only got one set, and they are getting harder and harder to find, so not sure I want to chance screwing them up. How about just putting in a larger 1.88 exhaust valve, would that help at all?
Hey Mark, I know this is not a BBC, but I gasket matched a set of RHS Pro Action 1(SBC) and also did a bowl blend, that area right behind the valves on intake and exhaust both protruding area into the valve seat. Is that common on even the aftermarket performance heads? And what is the common pick up in cfm when you relieve that area and widen the throat of the port?
That 30* top cut you're using is not that good. You'd pick up a bunch more by making that 38-40. I would recommend using Mondello's cutters, they're MUCH better...' fyi
ROFLMFAO!! Do you have any idea how hard the valve bangs on those seats? I guess not! A tiny little tap tap with a screw driver ain't going to do jack shit! ROFLMFAO!!!
Two intake runners point to center of cylinder, two point at cylinder wall. Word on the web is that in reality, the good port looses some intake charge out the exhaust valve, while bad port looses less because it’s pointed away from exhaust valve. I think the engineers done fine, and we don’t need to worry about it much. Mark does awesome work.!!
@@TonaldDrump686 I think you may need to do more research , because the port you are calling bad is really the good port. You are baseing you conclusion off of flow numbers and not wet flow or ignition timing requirements . I have spent 46years on a flow bench and also working with my wet flow bench that I designed and built over 30 years ago. My wet flow bench works with the intire intake track including a piston in the clear plastic cylinder. The BBC head has what I call 2 chevy ports and 2 ford ports. The ford ports you are calling the bad ports are the standard in all NASCAR heads today. If you want to take a look at a project I worked on for CID cylinder heads. Check out their symmetrical port BBC Chev head. It has all ford bad ports. This head will run with 26degs of timing and will make at least 30hp better than the Brodix SR20 head on the dyne on the same engine. We have done the testing. I am impressed with your work and the results you have gotten fron the old 781 heads. Keep up the good work. Its not an easy head to FIX.
I enjoyed the first of your videos but have grown tired of the snippets of video you're showing. You should be combining several videos - maybe doing the whole build in 3 or 4 longer videos instead of, well, I don't know where your series ends and I won't find out because I won't be watching them. I'm sure your info is legitimate but "Part 22"? and you're not even close to the end of the build? Sorry, but I've grown tired of chasing your video snippets. My mild street, 781 headed 454 is already built anyway.
