skinny z

PAC's 1219 has the same spec as COMPs 26918 (both are single beehive springs).
While I've had good luck with COMP, Jones suggested the PAC replacement and seeing as I'm replacing everything cam related, I'll probably go with that.
It's a given that high RPM valvetrain control, especially with a heavy hydraulic roller, is greatly enhanced with the small spring and retainer the beehive/conical spring offers. There's upwards of another 1000 RPM of headroom by some accounts. And that's with a spring that has less seat and open pressure than would otherwise be needed. And excessive pressure can be just as hard on parts as having too little.

As for the XFI's, the profile is aggressive considering it has a .360" lobe even with smallish duration (high 270's to low 280's). It's not unique to the XFI line however, but in general their ramp rate is more intense than COMP's XR. That too can be hard on parts. That said, I ran an custom XFI cam for many miles in one of my 350's (274/282, .359/.356 lobe). Noise aside, it was otherwise trouble free.

84 4+3

I will ultimately use what is recommended I've just heard of the XFI lobes being hard to control even with good valvetrain. A good beehive doesn't scare me but if a better part is recommended I will use that, you know?

skinny z

I'd sure like to browse the used NASCAR parts warehouse...

F-BIRD'88

Skinny, with your history using the Hydraulic Roller stuff I don't see why you'd want to hesitate running a Solid Street Roller set up.
Especially if you want to rev it up that high.
LESS noise, more POWER, Longer Service LIFE.

Fast355

iTrader: (2)

There is a reason I am going to one. Not that I am having any issues with the hydraulic setup. I just want more power and I like the mechanical sound.

skinny z

There may be something to that F-BIRD.
That said, although past RPM's were approaching 7k, this go around might see me dial it back a little. Maybe shift at 6200 and try to carry another few hundred RPM.
FWIW, my target MPH of 115 is reached at 6100 RPM calculating 10% converter slip at the stripe.

If it weren't for one failed link-bar, hydraulic rollers have never failed us in anything the crew has put together. In all fairness to the broken COMP short travel lifters, they were nearly 60 000 kms/ 34 000 miles old. And were really pounded for the last racing season (2017).

84 4+3

For those keeping track at home:
Jones specs:
240/250 @.050
.375/.360 lobe on a 110 LSA

Cam motion:
234/242 @.050
.350/.350 lobe lift on a 110.5 LSA with a 107 ICL

My current observations are the cam motion one would be a little more streetable but the jones would make better overall power... I may reach back out to Jones and ask why so aggressive and if favoring street driving over track use would sway his specs some.

Thirdgen89GTA

iTrader: (5)

The first cam in that list sounds like the Lunati Voodoo cam, and it has 66° Overlap.

That is the same specs that re in my LT1 swapped GTA. I have AFR 195's, and a ported LT1 intake, with 2210LTs.

You will NEED gears. The cam does not make power below 3000rpm, and if you get below 2200rpm, it will start to shudder.

F-BIRD'88

Skinny. You need to get beyond those girlie cams with the sissy squish hyd lifters.
Heres your street strip cam.
Howards street roller # 111313-08
Use the Howards recomended street roller 1.437" dual springs #98441 just as they recomend.
279-279 247/247@ .050" 108 LSA 104/112 .022"lash. .585"/.585" lift
This will get 'er done with all the different intakes you might want to try out..

If you want to analyze it in programs.
its 279°. @.020". Seat to seat is " .006" + lash" 288° running.. Varying the lash setting +/- changes this number +/- for effect..

Orr89RocZ

iTrader: (20)

comp had bad batch of springs, can’t remember when that was but was a supplier switch. But pac also makes beehives with quality materials. Springs can break a lot of different ways. Maybe material, may be something wonky in the valvetrain setup, harmonics, etc. Not sure what your case was. But how many 200+k mile ls motors are running around with hydraulics and beehives? Lol they dont seem to have a problem either. An ohc nissan is way different animal than ohv small block, so i wouldnt draw any conclusions based on that. I mean diesels also run them but dont rev over 4k and dont have a lot of spring either. Not used in other pushrod oem applications that i know of, and likely because of the maintenance and reliability.
I can say solids dont necessarily need a lot of maintenance, but they are a wear item that do need occasional checks that hydraulics do not. Its not a big deal either way i just dont see why it would be preferred on a 6700 rpm setup. Not max effort. All the late model hyd roller setups i see work fine. I had several, no complaints. The right lobe and combo of parts, proper valvetrain setup and geometry will make everything go smoothly, in any application

84 4+3

So I reached out to Jones again, he made another recommendation. (We talked a bit and I think it is a good idea to back down where I want the car to perform slightly.) We agreed on a 6000 RPM peak with carrying power up to 6500 or so. This will make more power from idle up to about 6000 than his first recommendation but will be down about 20 HP where the other one peaked.

Specs:
231/239 @.050
.343/.348 lobe lift on a 110 LSA.

I kind of came to the conclusion that I would be favoring street use and this would get me where I'd like to be but be a lot more drivable. I think this is the path to take on my engine.

For those keeping track at home, the other two are as follows:
Jones specs:
240/250 @.050
.375/.360 lobe on a 110 LSA

Cam motion:
234/242 @.050
.350/.350 lobe lift on a 110.5 LSA with a 107 ICL

Orr89RocZ

iTrader: (20)

You’ll love the 231/239 cam. Thats the perfect street size for a 383

skinny z

Nice to hear about another Jones successful interaction.
That guy sure deserves some props.
Question regarding the cam spec. Did he give you a part number? Typically his PNs include the lobe he's selected. Going through his two lists of hydraulic rollers, I can't find a match for the .050" timing or the lobe lift. That said, anything he'll make for you would be truly custom and would undoubtedly come from a pile of blanks.
Speaking of which, does he have cores in stock? I believe it was mentioned he was out of step nose cores and that is what you have.

84 4+3

Kind of what I was thinking. Seems that 231-233/239-242 range is pretty popular. I have a 236/242 in a poncho 400 and it's mighty fun even with a low compression ratio.
HR73353-75348-110. I forget to ask about a step nose but had mentioned it. Will reach out again to confirm. I have the parts to run step nose or cam button but if I can use a retention plate I'd prefer that.

Fast355

iTrader: (2)

I wonder if he could regrind my nearly worthless 395' Marine/Ramjet/HT383 cam to anything worth while. It is a GM steel core, just too small for anything I would ever run.

skinny z

I know Jones will regrind any given core. There's obviously a limit though. Not only with the change in spec but also the surface hardening.
That said, I've had conversations with Jones about this and he knows the limit of the GM cores but says the aftermarket stuff is a crapshoot. It might be worth investigating but keep in mind that'll undoubtedly produce a reduced base circle and all that that entails.

Here's a link to a discussion at Speed-Talk that you may find interesting.

https://www.speed-talk.com/forum/viewtopic.php?t=65078

skinny z

I've gone through the Jones Cams catalogue and as usual, the profile numbers given in the cam part number don't match up exactly.
Everything I've inquired about looks to be a tweaked version of his catalogue profiles. Makes sense.

F-BIRD'88

Most all the racing cam companies should be able to re-grind yiur OEM hyd roller cam.
As said the origional LSA has to be close to the new cam lobes LSA.
That lowly lame OEM HR 305 "peanut cam" with its 109° LSA should make for a usable core for regrind to a performance hyd roller or solid street roller cam like the XR. or the Voodoo SR series.
All you need do is contact your favorite cam company.. As long as its not damaged or the diz gear is not worn out they should be able to use it to make you your next cam. Seems a lot of stuff is just not available.
Other previously loved roller cams may also be suitable as cores for re- grind. Again the LSA has to be close within a few degrees.

skinny z

The entire lobe gets involved so the base circle is also reduced.
If the surface hardening is sufficient, and only experience knows if it is or it isn't, the lobe lift could actually be increased.

Fast355

iTrader: (2)

395' cam has the same 109 LSA but starts out at 196/206@ 0.050 and .431/.451 lift.

skinny z

What's your proposed spec?

F-BIRD'88

The cam lobe lift is increased by reducing the cam lobe base circle. a low lift stock like cam lobe will have plenty room to gain lobe lift by regrinding within reason.. Longer push rods may be nessessary if your build does not include block decking or head deck milling.
The cam company will advise you on whats possible and practical. If they do not have cam cores on hand they may well welcome re- grinding your good condition previously loved cam core.
They may need to inspect , first, to advise.
Could be cost efficient.

84 4+3

Looks close to me.

Fast355

iTrader: (2)

236/242 @ 0.050
0.3775/0.380 lobe lift
I would like it on a 110 LSA, I know the LSA can be changed but not much. Luckily its already on a 106 ICL too.

84 4+3

That's almost exactly what I'm running in the Pontiac, I have a little less lobe lift.

It does not like to run cold lol.

Fast355

iTrader: (2)

I could see a carb having some issues on cold start. Hopefully sequential port fuel will be more forgiving.

84 4+3

It's not so much the cold start as it is slamming it into the converter in reverse up a 25 degree incline to back out of the garage... Does not like that until it runs a minute. Then you gas out the house. Anything above say 55 and it's fine however.

Sequential should be very forgiving lol. Unless it's tuned with a potato.

Fast355

iTrader: (2)

Looking at what the camshaft, lifters, pushrods, springs, retainers and locks will cost me to be able to run a much more aggressive solid roller I think I may just stick with a hydraulic roller.

I put 100 miles on the Express last night in some really twisting, winding 2 lane and dirt roads. Running on E85 it happily loafs along at 40 mph @ 1,250 rpm in overdrive with the converter locked even up some decent hills. At 75 mph @ 2,300 rpm it climbs a mile long 8% grade without even coming out of lockup. No spark knock at all just nice smooth torque output. I got on it to WOT accelerating on a merge area from a hard right corner at a ~25 mph roll and in no time was rolling 80 mph still in the merge lane. Merge lane is a couple hundred yards long. I am getting ~15 mpg on E85 and it is nearly 1/2 the cost of 93. As much as I love power it has alot as it is.

I think I may just swap in this hydraulic roller grind and call it good. The wider LSA should make the torque curve broader and the later IVC will drop the dynamic just a little to make running on 93 octane with a decent timing curve easier. With a 1.6 rocker is should be about ~228/234 @ 0.050 up from my current ~218/228 @ 0.050.

https://www.summitracing.com/parts/h...make/chevrolet

84 4+3

The summit in house roller grinds are also really nice too fyi and are in the duration range you are looking for.

Fast355

iTrader: (2)

8802 and 8803 both look decent and they are dirt cheap for a billet steel roller right now too.

The 8802 has less overlap and a later IVC then my current cam. I modeled it on DD2003 the other day. It would work well with both the truck manifold and the Pro Flo clone.

Fast355

iTrader: (2)

How is the cam search going?

I too contacted several vendors. So far I have one recommendation. George @ Clay Smith recommended a cam I believe was designed by Chris Straub over the phone. Told me alot of guys have these in trucks, suvs and vans that tow with them so that their SBC would have some get up and go when needed. Seems like a big stick for a low compression 350 in a heavy truck with a trailer hanging behind it. That being said my 383 probably would like it, but the 8802 and 8803 make more power on engine simulation programs while being at a lower dynamic compression ratio with less overlap.

https://claysmithcams.com/hr-8082-8-...k-torque-3800/

Luke @ Howards basically told me we don't know how your engine is even running the way it does run, leave it alone. Also mentioned that dynamic compression ratio was basically dirty words and not something they mention on basis of cam selection. Also mentioned that he would suggest something around high 230s to 240 degrees @ 0.050 with an 11:1 engine. I guess they need to look at some of the LT1 builds Ellwein has done. Some are ~12:1 with less cam and 11.5:1 with low 220s @ 0.050 is common.

Still waiting on a response from Jones.

skinny z

That's understandable.
In our terms, we're talking about a SBC and the more generalized application of being a street/strip kind of deal.
Pump gas, results outside of WOT, etc.
Over the years, some guidelines have been established as to what works. E.g. A 9:1 DCR we know from experience isn't going to fit in the above little box. So as an example, it's extremely finite. Kind of like Vizard's 128 rule.
For the guys at the end of the cam tech line, they know too from experience (or should anyway) that a WOT racing engine has a different sort of dynamic going on. And the resulting DCR from intake closing and SCR takes on another kind of relevance. A really low DCR can have very good cylinder filling if the rest of parts are doing their job. The VE goes up but not necessarily the DCR. That compression pressure is achieved in different ways.
For our group, that being the +/- 10.5:1, NA, pump gas, gotta go racing and then groceries on the way home crowd, I feel DCR still plays an important part in spec'ing an engine.

84 4+3

I'm going to go with that second jones grind. Fits the bill imo and isn't anything overly aggressive. He also recommended PAC beehives to keep it easy on everything. I feel with those specs a beehive is very reasonable. I think I will look into lighter valves though just to play it safe. But I think my search is done.

That all being said I need to save a few bills up to make the purchase. The cam alone costs more than any one single piece I've purchased for the bottom end lol. Not saying I bought crap bottom end components but rather that I got everything dirt cheap...

skinny z

The valves are your choice but you might want to consider a lightweight tool steel retainer as opposed to valves. Might save some bucks and be easier in the process.

skinny z

Which PAC spring?

84 4+3

He also recommended tool steel retainers. The valves currently aren't anything special and I would prefer to put something I can trust more in it but I see your point.
His part number was JRC18X which I believe (based on the supplied specs) comes out to PAC 1218x.

skinny z

That's great info. Thanks for that.
I'm familiar with that spring as well as the next up the list which is the 1219 and 1219x. That'll most likely be my route. I have the retainers which are COMP pieces however the spec between the PAC and COMP is identical so I'm looking to swap them over. Probably the only part of the valvetrain that won't be brand new.

Fast355

iTrader: (2)

Should be a fun build. Mike Jones did just tell me he is months out on a step nose cam.

I then asked about having the brand-new GM 94666492 cam I still have sitting in the GM cam tube reground. I had forgotten that I had it. Getting a GM cam reground is about 3 weeks out.

He suggested
224/228 @ 0.050 on a 112 with 0.544 lift. Nothing in his lobe catalog has those exact specs, but 280/286 should be very close.

That is likely the one I will end up going with. 280/286 @ 0.050 on a 112 LSA and 108 ICL puts my dynamic compression ratio at 8.5:1. Engine analyzer puts that setup in the 535 hp @ 6,000 and 540 tq @ 4,000-4,500 range with the cutouts open. Down at 2,800 rpm where the torque converter stalls it shows a sold 485 ft/lbs of torque. Through the muffler it show 508 HP @ 6,000 with 522 TQ @ 4,500. Down at the hit at 2,800 it is showing 460 ft/lbs. I will take that power loss for not having to listen to the small block yell all the time. The Jones design also has a bit less overlap than my current cam profile. Desktop Dyno shows roughly the same results as Engine Analyzer.

skinny z

Therein lies my quandary.
As an example, which 280° lobe do you pick?



There's certainly going to be a difference in performance not to mention the different requirements of the valvetrain. At least from a longevity standpoint. Stability too.

Fast355

iTrader: (2)

I fight this same thing with the LS fan boys. I will avoid recommending a BTR, Texas Speed, or Cam Motion camshaft for this reason alone. I will use a Comp Cam, a Lunati or Crower or literally anyone else that provides fully detailed specifications over someone that does not. I do 1-2 LS cam swaps a month and recommend more than that for swaps into all kinds of non emissions vehicles that are being tuned.

84 4+3

I personally like data... when people say "it's a stage 2" well a stage 2 what? That means absolutely nothing to me. Just like full bolt ons... because that list varies depending on the person.

Orr89RocZ

iTrader: (20)

thats the funny thing. Depending on the combo, you may not see huge differences in performance numbers with those lobes, despite big .050 differences. The last lobe may be the more obvious difference but the others within a few degs, couple of hp maybe depending on the induction package.

ive seen it time and time again, the hundreds of aftermarket lsx cams for those stock head stock intake cam only cars. They vary a decent amount in specs and lobes but always make about the same power. Plus or minus 10 whp maybe. Closer you are to maxing out the intake and head the less the cam matters imo. If you are close there isnt much to gain.

now if you had a big head big cube deal, yeah you will likely see a big diff between 222 at .050 and 234 at .050.

regarding valve train life and all that, yeah could be different depending on parts used. If geometry is perfected and good parts used, you could see long life with just about any lobe. Lower acceleration rate lobes i would expect to live longest all else being equal. Ive seen the cheap springs wear out faster than good springs. They lose pressure. Valvetrain is an interesting subject

skinny z

I can agree on the output side. Any sims I've done show only marginal gains at the top and HP and TQ below peak to be about even. This is something I have to work through with the next cam and this comes around to the longevity vs performance conundrum.
My XFI custom cam had a .360" intake lobe (274@.006", 224@.050") and it sounded loud in comparison to the XR which had .335" lift (276@.006", 224@.050'). Was the increased noise harder on parts? Both cams had worn lobes but still looked serviceable with the 274 at 30,000 miles and the 276 at 40,000 so it's hard to say.
Yes, the valvetrain is an interesting subject.
Maybe Jones will explain to me what I can expect between that 280/234 and the 280/227 in the chart above in terms of that performance vs longevity metric I mentioned.

Fast355

iTrader: (2)

I agree, its alot like say a CC306 in a LT1 with stock aluminum heads. The cam can make far more power than the stock heads support. On a stock headed engine the HP curve flat lines for 1,000+ RPM. The cam wants to run to a higher rpm, but the heads choke it because they only flow ~210 cfm. Put that same cam into a LT4 and it actually has a curve to the HP curve.

Fast355

iTrader: (2)

Now this is purely my opinon here. The quicker your ramp rate the more potential for wear. Some of the max endurance stuff has much slower ramp rates. This preserves parts. I have a friend that builds and runs 410 sprint cars. They have massive spring pressure over the nose, shaft mounted Jesel rockers, etc. The 0.050 is big however the 0.006 is massive. The ramps are not as quick as some of the hydraulic rollers on the market. 49-50 is a pretty aggressive lobe and not something I would want turning 8,000. The more intense the lobe, the more spring pressure that is needed to prevent lifter toss as RPM increases.

84 4+3

I've always heard for all out sprints the faster ramp rates are better but endurance stuff does generally have softer ramps. The COMP LST (low shock technology cams?) interested me because their overall duration seat to seat is lazy but the .050 to .050 is very aggressive. They allegedly work really well.

84 4+3

I am about ready to pull the trigger on the jones grind. funds all in a row, just gotta get past this surgery and I'm in the clear. hopefully by the new year.

skinny z

I'll see were those those two grinds stack up in my library of sims. It be interesting to see how Mike's predictions play out.
I may have to be a little inventive on reconciling the .050" and lobe lift with a catalogue .006" timing number. As mentioned, what he specs doesn't necessarily match up with any particular part/lobe number.

84 4+3

I do have a feeling the second grind will perform about to spec. I am figuring ~435 crank hp and 400 ft-lb of torque. Anything beyond that I am very pleased. The first grind seems a little on the aggressive side for the given range. But again, he knows more than myself for sure.

skinny z

Spec 1: 286/296 on a 110 has 71° overlap. (240/250 @.050 .375/.360 lobe on a 110 LSA)
Spec 2: 277/287 on a 110 has 62° overlap. (231/239 @.050 .343/.348 lobe on a 110 LSA)
You could go any number of ways with that advertised number. I picked something that looked close and had a good fit with the .050" and lobe lift.
Note to mention the increased lift in the overlap triangle. Just a first glance I think you can see where 20 HP has gone. But I'll bet torque below peak is way up.

What's the compression ratio? Stil 10.8:1?