dan_t

Just wondered if anyone has any opinions on this cam?

Engine is a

85 Forged piston engine - 10.8:1
87 Alloy Heads
No AIR
No Cats
Straight Through Exhaust - Mufflier Eliminators
7730 ECM (MAP) with Custom Tune
Auto TH700R4

I'm looking to get headers on there and do something with the Intake at a later date - LT1 Conversion? Modified TPI?

Its not a daily driver. I'm after some lope and more performance. How does this cam suit?

227 int./233 exh. 050 - 0.489 int./0.504 exh. lift - 110LSA


Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,800-6,200
Intake Duration at 050 inch Lift: 227
Exhaust Duration at 050 inch Lift: 233
Duration at 050 inch Lift: 227 int./233 exh.
Advertised Intake Duration: 268
Advertised Exhaust Duration: 276
Advertised Duration: 268 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.489 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.504 in.
Valve Lift with Factory Rocker Arm Ratio: 0.489 int./0.504 exh. lift
Lobe Separation (degrees): 110

vader86

It really needs the LT1/MR intake, it wont go well with TPI

dan_t

if I decide to go the LT1 route do you think it'll WORK with the TPI for time being? or am will I be taking a step backwards?

dan_t

or could you advise on a Cam that will be more suitable but has some Lope?

dan_t

Any more thoughts?

mseven

Sounds like a lot of camshaft for a 350 to me, but I like the duration @50 #s like the CC 306, GM 846 or maybe a zzx(239 239 @50), if going big in a 350, no DD, I would also be looking at a solid roller. At that point you would be doing quite a bit more to that motor, regardless all would need a better intake, good heads, headers, converter etc. as Vader mentioned. If well tuned there would be very little lope. mo

tequilaboy

A cam like that will have some lope and you will definately loose torque below 2500-3000 rpm. Otherwise, its tough to imagine making less power than a stock tpi cam through the midrange and top end.

In the interim it will likely slow you down, due to the reduced launch torque.

Once you add an intake, headers, gears and/or converter you should see some gains. Of course you could always wait to do the cam until you have the intake and other parts, but what fun is that right now, when your itchin' for a new cam.

I ran a similar grind (Comp 503) with a tpi base and ported SLP runners for a year or so. It worked fine, but I already had headers and 3.73 gears in a 4+3 car, so I didn't really mind loosing a little low end torque.

JAKE

Do you mean by "WORK" that the engine will start, run and be driveable?

Jake

dan_t

I obviously dont want to be loosing all the power but I DO want to get a nice Lope. I heard that a tight LSA 110 will make it lope more without loosing as much torque?

I'll rarely see less than 1.8-2k as its an Auto with 3.07 Perforance ratio.

vader86

Well, its goin to lope some, but using the same motor and different intakes, that cam would make the car feel kinda sluggish off the line.

Youre mismatching an intake thats made for low-rpm, with a cam that wants high-rpm. Midrange power should be alot better than a stock cam with TPI intake, but to 60mph I'd not be surprised if it was actually slower. If as you say it stays less than 3K rpm most of the time, I'd say its not going to be a fun car to drive.

dan_t

Vader - any recomendations on a more suited cam? Something with Lope that will work with TPI for time being but won't need changing out when going to an LT1

vader86

Nothing comes to mind.

Anything with lope that you can hear is not going to be suited to low/midrange use.

You can certainly go with the basic MR cam, the ZZ-9, and it'll work fine for both setups, but isnt going to have noticable lope after tuning. But I think this cam is kinda small for the MR. I guess you could get something ground to similar specs, and then change the LSA a little for some more overlap.

JAKE

Since you asked for an "opinion" and "thoughts" on the cam, here's mine.

First, it's a flat tappet, which I don't like. A roller is the way to go. Also, there have been many flat tappet camshaft failures recently due, in part, to changes in the engine oil formula.

Second, there isn't nearly enough valve lift. Lift should be in the mid .500 range, like .550 +

Third, because it's a flat tappet cam without much valve lift, the ramps aren't going to be aggressive enough. This will limit the amount of power the cam can make.

I'd be looking at a hydraulic roller in the duration range of 218 In/224 Ex or even 224 In/230 Ex. There are several cam companies that make cams in those ranges. CompCams has two series of hydraulic rollers, Xtreme Energy and XFI that fit the bill. The complete specs are on their website.

The 224/230 will give you the lope you're looking for. I ran the ZZ9
(212/226) in a 86 355 TPI engine and, while it didn't hurt bottom end torque, it was barely noticable at idle.

Just my thoughts.

Jake

dan_t

but i've got a flat tappet block - how would i go about using a roller cam?

vader86

You can convert to roller cam, there was a kit available to do that from Lingenfelter. I don't have the link.

tequilaboy

If you just want it to lope, you could cycle the egr at idle. That ought to do the trick.

It might take some trial and error with the egr duty cycle table to get it to sound right.

It would be completely pointless of course, but it may be possible to make it sound like it has a cam.

Vetracr

From my experience you are going to have trouble getting a MAP sensored L-98 to work with a 110 LCA degree cam. I ran a 112 degree LCA Lingenfelter cam on my 350 and could only get 12" of vacuum at idle. FWIW, I'd convert to a roller cam with a 112 degree LCA with 220 degrees of intake duration with a valve lift .030" to .050" less than coil bind on the head.

Larry

JAKE

Right, Larry. I should have mentioned he should widen the Lobe Separation Angle. I'm running 114 on the CompCams XE 224/230 in my 415 L98.

Jake

dan_t

this is all so confusing lol

jeffyc

i run a 236/243 @.50, with a lsa of 110 with my map 383 L98
so its possible