was wondering if anyone has bought anything from dh-racing.com. I was looking at the valvetrain package and its a lot cheaper than skunk2. how's the quality? I read the cams are re-grinds thats why they are cheaper. Does that make any difference? thanks for any feedback
dh-racing valvetrain package?
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you know what? Dave Hickman doesn't sponsor us. So those springs are for his eliminator cam's specs (lift, ramp, duration, overlap).
you need to find out what the starting and opening seat pressures are on those at stock installed heights (if that's what he calls for) and what the coil bind lift height is.
each brand's springs has their own seat pressures and coil bind specs.
they should've spintron those to know when they fail.
so find those out first. you can't just go by brand name and interchange them on the cams.
their website isn't exactly full of helpful spec info on there so you'll have to contact them directly.
you run into problems whether you get valvesprings which are too stiff or too soft for the cam.
interference fit springs are the way to go for sure these days.
I can't tell if those springs have been nitrided by their website pics...but that helps on the wear front too.
what cams are you running anyway?
You know who makes good steel valvesprings?: PSI in Michigan...consistent specs and just stiff for that height and coil bind you need...they make springs for the IRL,CART, and big name engine builders...
you need to find out what the starting and opening seat pressures are on those at stock installed heights (if that's what he calls for) and what the coil bind lift height is.
each brand's springs has their own seat pressures and coil bind specs.
they should've spintron those to know when they fail.
so find those out first. you can't just go by brand name and interchange them on the cams.
their website isn't exactly full of helpful spec info on there so you'll have to contact them directly.
you run into problems whether you get valvesprings which are too stiff or too soft for the cam.
interference fit springs are the way to go for sure these days.
I can't tell if those springs have been nitrided by their website pics...but that helps on the wear front too.
what cams are you running anyway?
You know who makes good steel valvesprings?: PSI in Michigan...consistent specs and just stiff for that height and coil bind you need...they make springs for the IRL,CART, and big name engine builders...
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what are the specs on that cam? you can make a decision without knowing the specs and how much it will shift the powerband up or how much of an effect it'll have on your cylinder pressure (and the need to change your CR).
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thanks.
Does he reduce the base circle on those regrinds?
I guess heat treating them is supposed to protect them but you wonder about the lubricity (ability to hold the oil on the surface ) of regrinds after they've been ground down at the base circle. I forget: are his regrinds hard welds or base circle grinds (to get more lift from the stock cam core) ?
Does he reduce the base circle on those regrinds?
I guess heat treating them is supposed to protect them but you wonder about the lubricity (ability to hold the oil on the surface ) of regrinds after they've been ground down at the base circle. I forget: are his regrinds hard welds or base circle grinds (to get more lift from the stock cam core) ?
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I have actually purchased a complete head kit from dave hickman, untuned w/ cam gears set at o and fuel pressure at 43 psi dropped from a 16.3 to a 15.2 1/4 mile, still on stock clutch, but the quality of his work is excellent I am not to sure on the specs anymore, have to find the emails I had printed out, but what he sells is quality and if any problems will help every step of the way exa. all the components he sent me were off a 94 teg and I have a 91 helped direct me on running the vac. line for the map sensor to the throttle body instead of the fire wall and also the throttle body does not have coolant running through it, told me how to bypass it, which now I know I should have known lol (commomn sense). I will vouch for Dave and if you notice on my profile you see my engine on the stand then you look on dh-racing.com at the race motors you will see my engine towards the bottom, and MD I will talk to him about sponsoring the sight, hope this helps a little.
MD, where would one buy interference fit springs? I know you mentioned PSI in Michigan, but I would ask about something for a mild cam like the 403's and 404's. I know that crower makes their own, but I would like to have the best springs, theoretically. I'm not asking because I want them, only for the sake of knowledge.
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the key is to run the tightest closest interference between the the inner and outer spring without running so tight that they affect each other and generate too much heat, stressing the spring itself. The good interference fit spring manufacturers have tight consistent clearances from one set to the next. It's not a mish mash of of clearances on the fit.![]()
Interference Fit: This term is used in reference to valve springs. The inner spring is a very tight or push fit in the outer spring. This allows lower spring tension to be used. This type of spring requires lots of lubrication or spring breakage may occur.
PSI is well known to the racing community for their consistency from one batch to the next.
There's lots of manufacturers of interference fit aftermarket dual valve springs for us, including Skunk2 and Manley.
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308 =
advertised duration (duration when the valve is just coming off it's seat) or duration @ 0.05 in. valve lift? or duration @ 1mm valve lift (0.04 in.) ?
0.464 in. max. lift is 11.79 mm .
once you clarify the duration @ 1mm, you can compare his cam spec to the other VTEC cam specs here to see where they stand.
yes, as we've told you here: the head's max flow capacity (flowbench cfm @ 10-25 in. water vacuum) determines peak hp potential. The cam just holds the door open longer. The door has to be wide enough to let the entire party in.
looks like an intermediate cam like a Stage 1 Skunk2.
can he tell you the intake cam's valve closing spec ABDC?
advertised duration (duration when the valve is just coming off it's seat) or duration @ 0.05 in. valve lift? or duration @ 1mm valve lift (0.04 in.) ?
0.464 in. max. lift is 11.79 mm .
once you clarify the duration @ 1mm, you can compare his cam spec to the other VTEC cam specs here to see where they stand.
yes, as we've told you here: the head's max flow capacity (flowbench cfm @ 10-25 in. water vacuum) determines peak hp potential. The cam just holds the door open longer. The door has to be wide enough to let the entire party in.
looks like an intermediate cam like a Stage 1 Skunk2.
can he tell you the intake cam's valve closing spec ABDC?
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