G1 twisted wedge valve clearance

[grumpyvette]

I have a 383 stroker that has 10.5:1 compression with trick flow twisted wedge g1 heads. The max lift I can use from a cam before the valves hit a piston is .520 if I use different springs. "So long as you stay at or below 236* @ .050" Duration, No less than a 108* LSA, you can go up to about .520" lift before piston to valve clearance becomes an issue." I need help on cam selection. I want a hydraulic roller cam. It's a non roller block. I'm trying to make around 500 horsepower. It's a street strip setup with a t56 transmission. Also 1.52:1 rocker arms. Thanks in advance!

first ID point out that those are the guide lines that came with those heads and
THEY DON,T ALWAYS APPLY, you NEED TO ACTUALLY MEASURE YOUR PISTON TO VALVE CLEARANCE AND VALVE TRAIN CLEARANCES
you will be taking a HUGE gamble if you don,t VERIFY your TRUE clearances, and ID also point out that the valve springs can be and should be UPGRADED for use with a roller cam as the load rates are different,on those heads currently than what you need for a hydraulic roller cam plus the fact that your valve springs and seals are at least 15 years old now, because they stopped selling those heads at least that long ago.
they are decent heads if in good condition but need better springs for a hydraulic roller cam.
It would help to know more about the car weight, rear gear, headers etc, and if you need to pass emission testing.
check the valve seals and valve guides for wear, as the G1 heads have a reputation for wearing originally installed valve guides


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I don,t know many or in fact any engine builder that doesn,t have some good model clay in his tool box for checking clearances

or a can of wd 40 to spray on the valves and clay too prevent clay sticking to parts measured, use good quality modeling clay, some crap like kids PLAY DOUGH, is SPRINGY and won,t give exact and consistent measurements, I pick mine up at a local arts & craft supply

almost every mechanics tool box needs a few basic measuring tools and supplies

https://www.amazon.com/Claytoon-Set...d=1466872286&sr=8-17&keywords=plastilina+clay

http://www.utrechtart.com/Plastalin...currency=USD&gclid=CN3G75zOw80CFQgaaQodKbgFjA

 

[philly]

ditto all but particularly want to double tap verifying your own PTV clearance regardless of what the cylinder head manufacturer says. you could easily discover that you can run a 535 ish lift at 240* or that you infact cant run more than 510 at 224... point is measuring your clearance for YOUR specific application is the only what to know what cam YOU can run in YOUR combo.

trick flow, dss, and several other companies sell an off the shelf piston in all the popular sizes that clearanced for the twisted wedge valve angles. in fact for ford 351w the piston in 4.030 forged with the big valve relief for 500 bucks a set for 8 not a huge expense and the new amounts of lift and duration you open up to with that new found clearance

 

[grumpyvette]

So today I did my p2v test and I have about .210 left to go until it hits on the exhaust and the intake did not even contact the clay. The cam has about .460 max lift. So in theory I should be able to go to about .560 right? Any cam suggestions that will make a solid 500 horses?

Heres a selection of hydraulic roller cams from fairly mild to fairly radical,in about the required range youll need to get 500 flywheel hp,theres about a 15-20 hp gain on each of these three cams as you add duration by swapping, but with a matching loss of street drivability, its a trade-off of better manors for more power, at each upgrade. keep in mind youll want the correct roller lifters rockers and guide plates and youll want to verify the clearances and rocker geometry,

CRANE,
http://www.cranecams.com/userfiles/file/294-295.pdf
MOREL ,
http://www.straubtechnologies.com/hydraulic-roller/

CROWER
http://www.crower.com/lifters-roller/

and

ERSON lifters

http://www.usaperform.com/solid-roller- ... 8_249.html

If your looking to make 500 horse power youll want a cam that allows those trick flow heads to breath up in the 5500-6500rpm power band,and headers that flow well, Id strongly suggest you have a long talk with the tech support guys at CRANE,CROWER AND ERSON before you decide,on which of these HYDRAULIC ROLLER CAMS YOU MIGHT WANT OR FIND SOMETHING SIMILAR, notice the duration range on the milder crane is 230 to the wilder crane at 240 @ .050 lift, with the crower nearly splitting the difference,in duration between the two crane cams, and yes YOU WILL NEED NEW VALVE SPRINGS AND YOU'LL NEED TO CHECK CLEARANCES CAREFULLY, but Ive personally used these cams and made over 500 FLYWHEEL hp in 10:1-11:1 compression ratio,383 engines.
I'd also point out that youll generally need a 3.54:1-4.11:1 rear gear to keep the engine running in its intended power band


Ive never had an issue re-using old push rods on new roller rockers with a good dose of moly cam lube on the tips , AS LONG AS the tips looked like they were in decent condition and not obviously worn,after, they passed a close inspection before they were used, most good brand name aluminum roller rockers have pressed in hardened steel push rod seats that are far less likely to wear than the tips of the push rods.
but I'D point out that the push rod length MUST BE CHECKED with a new cam, and NEW VALVE SPRINGS that the roller cam will require as the standard twisted wedge heads came with valve springs that won,t work correctly with the hydraulic roller cam

OBVIOUSLY that assumes you have no valve train clearance issues, binding or geometry or lubrication issues, and you set the lash or lifter pre-load on the valve train correctly and use the correct oil, and it certainly would help any engines durability to have provisions for adequate valve train oiling and a bit extra valve train cooling can be helpful on an engine designed for higher rpm use.

READ THRU THE LINKS


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