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Originally Posted by Tartilla
(Post 4939647)
Hard to say how you'll fare without the ski jumps. The help bias the port flow and induce swirl...helping keep the fuel atomized and assist in healthy turbulence. It should increase the cfm a bit.
Have you back cut your intake valves 30°? Helps with low lift flow..and getting the air moving earlier...allowing it to flow more on the larger valve opening phase. Larry tells me they are primarily for automotive applications, to improve efficiency at lower RPMs. This engine was OEM designed to spend its life at 1700 RPM. We NEVER run 1700 RPM, other than sweeping through it, getting on or coming off plane. I didn’t do the valve job. Given the builder primarily does high HP marine engines, I have to assume he did the valves properly for the application. And, to be honest, I haven’t really looked at the valves, as I wouldn’t know what I’m looking for. Thanks. Brad. |
Guys,
https://cimg2.ibsrv.net/gimg/www.off...2af31886b.jpeg Fun fact…. Guide plates are hardened. I wasn’t expecting that. I had to buy a 7/16” carbide reamer to open them up for the new rocker studs. Slow and easy, and lots of MolyDee cutting oil, and they cut like butter. Seemed to hold location pretty well, too. Coming together. Thanks. Brad. |
[QUOTE=Brad Christy;4939648]Tartilla,
I didn’t do the valve job. Given the builder primarily does high HP marine engines, I have to assume he did the valves properly for the application. And, to be honest, I haven’t really looked at the valves, as I wouldn’t know what I’m looking for. Beware....We would assume that HP engine guys with 30 years experiance would do things right, WRONG. I had 2 sets of AFR heads done with welding up corrosion and new seats. Dyno'ed and one engine was off 200hp from the other. Told that the one engine had serious leak-down in several cylinders. Ordered new AFR 385's and had them on order for 4 months so no engines this past summer. The valve job was so bad with bad margines and not seating due to warped seats, valves ground off center, the heads are SCRAP. I will never use that guy again! Not funny but he runs a very conpetitive Pro-Mod 950 cu/in plus car. Guess there is no care in good customers engines by some and it showed. |
[QUOTE=LakeBoat4;4939805]
Originally Posted by Brad Christy
(Post 4939648)
Tartilla,
I didn’t do the valve job. Given the builder primarily does high HP marine engines, I have to assume he did the valves properly for the application. And, to be honest, I haven’t really looked at the valves, as I wouldn’t know what I’m looking for. Beware....We would assume that HP engine guys with 30 years experiance would do things right, WRONG. I had 2 sets of AFR heads done with welding up corrosion and new seats. Dyno'ed and one engine was off 200hp from the other. Told that the one engine had serious leak-down in several cylinders. Ordered new AFR 385's and had them on order for 4 months so no engines this past summer. The valve job was so bad with bad margines and not seating due to warped seats, valves ground off center, the heads are SCRAP. I will never use that guy again! Not funny but he runs a very conpetitive Pro-Mod 950 cu/in plus car. Guess there is no care in good customers engines by some and it showed. I’ve actually since come to find out my builder didn’t actually do the heads. He sent them to the same shop my tuner’s family owns. The tuner does the automotive repair work and tuning, while the dad does the machine work and builds the engines. They are fairly widely known for building strong engines. Compression seemed strong all summer. https://cimg0.ibsrv.net/gimg/www.off...aa7fd556c.jpeg Thanks Brad. |
Guys,
Got one head torqued down and did some preliminary rocker sweep checks. Exhaust https://cimg0.ibsrv.net/gimg/www.off...ef8f0dfb2.jpeg On the base circle https://cimg1.ibsrv.net/gimg/www.off...a9ca68545.jpeg Mid sweep https://cimg2.ibsrv.net/gimg/www.off...366a94a71.jpeg Full open https://cimg3.ibsrv.net/gimg/www.off...5d4af8ce1.jpeg Well centered Intake https://cimg6.ibsrv.net/gimg/www.off...70f1e1c6c.jpeg On the base circle https://cimg7.ibsrv.net/gimg/www.off...1b7e65b86.jpeg Mid sweep https://cimg8.ibsrv.net/gimg/www.off...2cd1827e3.jpeg Full open https://cimg9.ibsrv.net/gimg/www.off...13aaad7bf.jpeg Well centered I’m pretty happy with the decision to drill and tap for the larger rocker studs. I’ve got probably double the base thread engagement, probably ten threads of engagement with the rocker nut after preload, and just about perfect rocker geometry, not being perfectly centered on the valve stem tip aside. Thanks. Brad. |
So, in hindsight, was it worth the effort compared to paying $800 (?) for the custom M10 studs?
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Originally Posted by Markus
(Post 4939830)
So, in hindsight, was it worth the effort compared to paying $800 (?) for the custom M10 studs?
I didn't pay $800 for custom studs. I'm sure those were for someone in my position that was unwilling, or unable, to modify their heads. That was the whole point behind drilling and tapping the heads for 7/16" base thread studs; to get away from the need for their "specials". These studs are an on-the-shelf existing part number that worked for my setup. As it happens, the studs I opted for only come in sets of 8, so I had to buy two sets, but they were less than $100 a set. Studs, pushrods and new valve seals were a combined total of less than $400, including shipping. Plus, it was fun, trying to Frankenstein it all together. Absolutely worth it in my eyes. Thanks. Brad. |
Originally Posted by Brad Christy
(Post 4939832)
Markus,
I didn't pay $800 for custom studs. I'm sure those were for someone in my position that was unwilling, or unable, to modify their heads. That was the whole point behind drilling and tapping the heads for 7/16" base thread studs; to get away from the need for their "specials". These studs are an on-the-shelf existing part number that worked for my setup. As it happens, the studs I opted for only come in sets of 8, so I had to buy two sets, but they were less than $100 a set. Studs, pushrods and new valve seals were a combined total of less than $400, including shipping. Plus, it was fun, trying to Frankenstein it all together. Absolutely worth it in my eyes. Thanks. Brad. Owning a machine shop help just a tiny bit,,,,LOL. |
Originally Posted by Wildman_grafix
(Post 4939833)
Owning a machine shop help just a tiny bit,,,,LOL.
At least a bit, yes. Thanks. Brad. |
Originally Posted by Wildman_grafix
(Post 4939833)
Owning a machine shop help just a tiny bit,,,,LOL.
by the sneaky backgrounds in the pictures its a full blown. " let's get it done" shop you have the set up those rockers being centered.. sooo much better than before 👍 |
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