I have a 90 corvette with an L98...This is not about the corvette, but rather about the modified L98 engine...I wanted to seek your advice here. I've posted here a few times before and got some awesome advice. I posted a few days back in the TPI section about this same build, but with the TPI intake...I actually just (yesterday) purchased a superram setup to to use instead. I want to seek your cam advice on this board with so many knowledgable L98 guys on the board.

I'm hoping to just expand my audience and ensure I get the best cam possible to enjoy the 383 L98 build.... Thanks guys for your help!

.....This is more or less a repost - BUT WITH A DIFFERENT INTAKE SETUP I need a different set of cam recomendations....You guys remember my thread here.... ....

https://www.thirdgen.org/forums/tpi/...your-best.html

Well, I stumbled upon a good deal from a veteran on the corvetteforum board in the F/S section for a superram, runners and eddlebrok base. Accel Superram Plenum & runner kit (billet lid) and TPI Edelbrock base

http://forums.corvetteforum.com/show....php?t=1536504

Judging by months of people saying I'd be happier with a different intake for a 383 ----I purchased it --- So no longer am I retaining the stock TPI. You only live once right? I'll prolly never build up another car in my life like this so let's do it right!

Keep in mind for this cam recomendation that this car will see the track maybe once or twice a year for FUN - not competition, and it's primary role will be a daily driver in the warm season. I don't mind a bit of lope in the idle, but I want the car to handle Kansas City rush hour traffic without dying or running too rough at idle, and I don't want a constant tuner.

My car is a 1990 Corvette L98 coupe with a manual ZF six speed transmission.

Mods:
4.10 gears, (I say this because at 70mph on the HWY in sixth gear my tach reads 2100-2200RPM with stock wheel size---from what I read on another site this means 4.10 -since I bought the car used from a dealership I don't know how to confirm this outside of this tach/mph comparison)
Hedman Elite Headers,
True Dual 2.25 inch Exhaust with Borla XR-1 mufflers
Steel Single Mass Flywheel, and Spec Stage 2 clutch.

I'm having a 383 Engine built with the specs below. I sent the vendor (http://www.precisionengine.com/) my 113 heads which he is porting. Precision Engine seems to be a great shop so far, I'm dealing with Ken and he's been patient with my questions, and is after a partnership on this build process to make sure I'm happy with it.

Specs are below.


 GM 5.7 block bored, honed, decked and align honed
 Durabond cam bearings
 Matching roller lifters and springs
 New sir steel rods 5.7”
 New cast steel 3.75” stroke
 Crankshaft micro-polished less than a 12 ra finish- (Eagle or Adept)
 Speedpro pistons with Molly rings
o 10 to 1 compression ratio
 Balanced rotating assembly
 New Melling timing set
 New high volume oil pump
 New gasket set
 New push rods
 New head bolts
 Customer’s aluminum cylinder heads will include the 2.02/1.60 valves
 120 lbs. springs
 3 angle seats
 Bronze guides
 Positive seals
 1.6 roller rockers
 Ported intake and exhaust runners
 Internally Balanced


It would seem from what I've read that the superram is well mated to the LPE219 cam? Is this 383 build still best suited to an LPE 219 cam?
What about an equivalent cam if the vendor can't get the LPE219? What RPM range does the Superram like to be mated with?

The vendor has a lot of exp. with this cam and has been happy with it in the past...
 Performance roller camshaft:
o 224/232 @ .050
o .501 lift
o 112 lobe center

What do you think about this cam with the 383/superram?


I would like one final sound off of help from this board in helping make this engine as strong, fun, and reliable as it can be for my daily driver application. I should note that the car will be running on 91 or 92 octane gas because that is the highest available in my area.

One last request---If you don't know what you are talking about please don't post(just read and learn with me), because it's hard to distinguish on the internet, who is speaking from exp, and who is rattling off unknowns.

Thanks for your patience and help in ensuring I get this right and am happy with my purchase!


Please post any CorvetteFevor, CarCraft, or other tech magazine/website type articles or links you have references to for this kind of 383/superram build up. Additional information would be awesome and I would love to read the links.

One last thing....What should this combination be good for in regards to HP/TRQ?

 

based on my experience, i have seen tons of LPE 219 350 superam combos and they are very streetable. in a 383 it will be very tame. still make decent power but tame. lol LPE is a good match for heads that flow really well on the exhaust side of the head. exhaust/intake ratio of 75% or better. so hopefully your ported L98 heads will have a good ratio. Else it might be better to go to a split duration cam

the other cam u listed would be a good choice too. the lift tho is on the small side of things but still will work. 1.6 rockers will bump it up. depends on your head flow but ported L98s should make peak flow near .550 if not higher.

a 383 will swallow that cam easily. so either cam will suit your daily driving needs but still make power to be a fun car

 

Haven't personally used a SuperRam, but many 383s using just about every other commonly available intake.

I was going to suggest the very similar GM "LT-4 Hotcam". It's a hydraulic roller like your stock cam and will basically slide right in there. Specs are very similar to the Lingenfelter cam. 218/228* @ .050 on a 112* LSA and lift of .525/.525 using 1.6 rocker arms. Maybe just a hair milder. It's a GM piece, available many places (including used for cheap) and has proven to be a good performing, reliable piece in many many engines.

I don't think you'd go far wrong with either cam.

Happiness on the street is often a cam that's about 10* less duration than you think you need.

Don't forget to budget for custom dyno tuning when you're done. You're too far from stock to rely on the stock tuning to run it well.

 

yeah i was gonna add, for a superram/HSR/miniram street/strip 383, i would like to run a 230/236 or slightly bigger like GM847 cam which is 232/242 i believe. for a streetable daily driver, i'd definately drop it about 10 degrees. a good 220/230 cam would be about right. the 224/230 comp cams xe274 is a good cam!

 

bump for a decision I need to make tomorrow before noon

 

I've found that usually when you get a couple of replies in agreement and then nobody else posts it's becuase they can't find much to disagree with. I think you'll make a good decision with either of these cams.

 

BadSS sent me this PM...I thought I'd put it out here since I'm linking the vendor to this thread and he won't be able to see my PMs...thanks BadSS. I did ask Ken for the head flow numbers if he has them.

You really need to have a good idea of what the heads are flowing and the exhaust to intake ratio. I'd ask the guy doing the heads to give you a serious on inflated estimate on what increases in flow he expects from the port work. If it's not much you'll want a little more duration on the exhaust side. If there was more work on the exhaust side than intake side,,, you might get away with a single pattern cam which can give you more power with less overlap. Plus with your true dual Borla system (excellent mufflers by the way),,,, so you'll get by with less split regardless considing most of these 3rd gen F-body guys are running a y-pipe into a single 3" exhaust. Plus,, the true dual and Borlas will let you tighten up the lope spread since you're going to have to get that SD system custom tuned to work with what ever you put in it. Let me know about the heads and I'll throw something at you that I know will work. You'll probably think I'm crazy though,, although on the engines I build,,, I routinely estimate their ETs in the cars within 0.15 seconds - many less than 0.1 seconds.

 

Aluminum l98 heads are d-ports which flow much higher than regular heads.

They work best with a cam that is single pattern. Like a 218/218 cam, or 224/224.

You dont want extra duration on the exhaust lobe.

 

let us know what u end up choosing

 

I gave the vendor my wish list today...but I'll for sure let you guys know what the exact cam I end up with is, and I'll post back some dyno numbers after I get everthing tuned!

I asked him if we could get the LPE 219 cam, and if we couldn't get that cam, something really close. I also linked him to this thread.

It helped that I saw this link below - stats are similar to my motor build.

Dyno Tests of Small Block Chevy Motors in detail

 

If I remember correctly, the heads used were the LPE CNC $1800 with core exchange ported heads. If you run that same size cam on heads that flow less, you're going to make a good bit less power than this and peak at a lower RPM. The smaller duration high lift cams work wonders with higher flowing heads, but for stock or mildly ported heads, the cam will need to be a bit larger in order to make decent power and pull decent in the upper rpm range of that intake.

 

Ken, the engine designer called me back and said he was talking with his engine production manager and they both just felt I should stay with a tried and true cam they have and often use on their 383s.

He said I would be really happy with it and they felt more comortable with it.

He restated the cam specs he strongly advised using, which were the cam specs of the original build, -----

The specs are 222/232 @50, 114 lobe center and about 494 and 499 lift.


Does everyone think this is okay? I told him I wanted to go with the LPE 219 because that was the cookie cutter cam that everyone suggested. He stated that he thought I would be better off with this cam for my purposes, and that the higher 232 exhaust number would give me a bit more torque and better match his engine.

This is taking so long because I changed the plans on him mid game and sent him the superram intake from forum member nucking futs....I also asked him not ship it to me till early december because I will be out of state for the next 2.5 weeks.

Comments on this cam? Will this make more HP/less HP, more torque/less torque? What is the difference between this cam and the LPE219? Will it be noticible/beneficial/detremential/neutral?

 

I used the LPE219 with the ASM Runners and 383. It had a massive 424 RWTQ at the wheels lol

 

I'd go with something like the newer Crane Z cams that have a faster ramp. They use much less seat to seat duration, to help with idle and low RPM drivability, but ramp faster to give same .050 duration for about the same power as others with same .050 duration. I'd go with the 218/228 Z cam, but that's because I believe I could easily pass emissions with it in a 383 or 406.