I'm putting together a 385 stroker with a Comp Cams XR282HR (hyd. roller)cam. Will be using the GM melonized distributor gear, as I've seen suggested. With AFR's and the Edelbrock Air-Gap, I want the installed distributor height perfect, for correct cam/distributor gear engagement. How do I verify a correct gear engagement? And, if not right, ... how is it corrected? Shims etc? Using a GM HEI. Thanks, ... another again.

Was it CC that suggested the melonized gear? If not, call them directly and ask them what is the correct dist gear. Is yours a steel billet or a cast core?

This is a cast piece. CC told me , quite awhile back ... to run a stock gear. However, since then, I've done a TC search on this subject, ... and found a 8/04 post (reply) by Wolfplace, ...where he highly recommends the GM melonized with all cast hydraulic rollers. Also, had another engine builder, that frequents this site, suggest the same. I'm hoping that Wolfplace will notice this post and re-state his position.

After several experiences with Comp's cast core rollers I can say without a doubt run the GM Melonized gear.

ABSOLUTELY DO NOT RUN AN MSD MELONIZED GEAR on Comp's cast rollers-- unless you like lots of iron chunks circulating in your oil because your distributor gear shredded and left you stranded in a questionable part of town... I have experience in this department. Twice I tried MSD distributor gears & Comp cast core HR's and both times resulted in failure, one of which was very short lived (and fragged all my bearings.) I used a 3rd Comp cast core HR with the GM gear and things looked perfect. I have since replaced that cam with the same grind on a billet core, tired of playing russian roulette with cast core rollers.

As far as verifying the gear mesh, spray the gear with machinists blue dye (aka dykem) and turn the motor over several times. Check the contact pattern. You'll need a slip-collar on the distributor to adjust, but usually raising the distributor up about .050" from bottomed out on the oil pump driveshaft is near perfect.

Also, what are your valvespring pressures? Too high and you'll eat the lobes right off that cast core cam.

Gokou:

Using AFR #8020 springs. 1.450" dia... 120 lbs on seat... to .550 lift. (according to AFR). Sound OK? 5500 rpm max engine.

Gokou:

Using AFR #8020 springs. 1.450" dia... 120 lbs on seat... to .550 lift. (according to AFR). Sound OK? 5500 rpm max engine.
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My position has not changed regarding the GM gear, use it. :)

The one gear I will not use on anything is the factory MSD one.
Don't really care how many people are "using it with no problem", I have replaced too many of them in the last few years to screw around with a gear that costs less than $50 plus honing.

Just a question but if your plans are for only 5500 why the 282 cam?

Those springs may work if you really keep the RPM under 5500 but are too light for an aggressive hyd roller like you have in my opinion.
They are only 300 @ .550 lift.
I would like to see another 40-50lbs open & another 20 on the seat.

I have very little use for cast hyd rollers, have seen them track at less than 400 open in a small block in more than one case but if you keep the pressure down it should be OK.

Mike (Wolfplace)

Thanks for the info. This 282 cam was part of a new engine, in hindsight, ..I probably shouldn't have bought from a local .... private party, quick talking, receipt and photo(s) carrying ... incompetent "garage builder" (buyer beware).
It was never installed, but ran a short time on a stand. I've had to completely rebuild ... rebore, repair forged crank, repair cam, align bore/hone. etc. $1500 additional.

Having said all that, .... it actually doesn't surprise me now, that this cam and spring combination is not correct. And, I'm now hesitant to use a cast roller. --- What brand & grind, steel hyd. roller,.... would you recommend using? This is a 10 to 1 engine, w AFR 190's (angle), Air-Gap, 23-2500 stall & 3.73's. Hoping to make near 500hp and same torque. Need enough vaccum for power brakes & ac controls. Will be installed in a street vehicle, with ocassional strip usage. Maybe now, 5800 rpm tops.

Appreciate all recommendations. I'm still budgeting here, so I'm looking for a durable cost effective piece, if possible. Thanks Mike, for sharing your knowledge and experience with us.

PS. I'm looking at the Crane HR-276-2S-12 IG. It's a hardened billet core. http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=119821&ivi=2&prt5 Search using pt. # 119821. ( For some reason, couldn't get a direct link). Appears the AFR 8020 springs should handle this cam according to specs. Will this grind get close to the 500hp/500tq range, with my combination, or do I need more cam?



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Brian

Mike (Wolfplace)

Thanks for the info. This 282 cam was part of a new engine, in hindsight, ..I probably shouldn't have bought from a local .... private party, quick talking, receipt and photo(s) carrying ... incompetent "garage builder" (buyer beware).
It was never installed, but ran a short time on a stand. I've had to completely rebuild ... rebore, repair forged crank, repair cam, align bore/hone. etc. $1500 additional.

Having said all that, .... it actually doesn't surprise me now, that this cam and spring combination is not correct. And, I'm now hesitant to use a cast roller. --- What brand & grind, steel hyd. roller,.... would you recommend using? This is a 10 to 1 engine, w AFR 190's (angle), Air-Gap, 23-2500 stall & 3.73's. Hoping to make near 500hp and same torque. Need enough vaccum for power brakes & ac controls. Will be installed in a street vehicle, with ocassional strip usage. Maybe now, 5800 rpm tops.

Appreciate all recommendations. I'm still budgeting here, so I'm looking for a durable cost effective piece, if possible. Thanks Mike, for sharing your knowledge and experience with us.

PS. I'm looking at the Crane HR-276-2S-12 IG. It's a hardened billet core. http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=119821&ivi=2&prt5 (http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=119821&ivi=2&prt5) Search using pt. # 119821. ( For some reason, couldn't get a direct link). Appears the AFR 8020 springs should handle this cam according to specs. Will this grind get close to the 500hp/500tq range, with my combination, or do I need more cam?



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Brian
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Brian,
I think your power goals are a little optimistic on an honest dyno especially with your RPM limits.
I do not like that Crane cam much for a 383.
Think your first choice was a better cam with 1.6 intake rockers.
Or, with your heads I would probably start with something like Comp's 3015/3036 lobes. 274/282, 224/230, 149/152, .537/.533, 108 sep.
More cam if you are going to RPM it a bit more like to 6500

While I do not like the cast core stuff, if you keep the pressure down to about 350-375 it should be ok.
Any more is probably a crap shoot in my opinion.
Billet core cams are quite a bit more money but I prefer them.

Springs, probably Comp's 978 at 1.800 or 977 at 1.850
Or you could look at trying the Beehive type springs, seen very good results with them.