[tjet]

I have a question regarding the lobe seperation angle on a cam.
Will a cam with 232* @ .050" with a 112 LSA have a similar idle as a cam with 224* @ .050" with 110 LSA?

 

[ap72]

nope. They are 2 completely different cams and will behave in two completely different ways.

There's a LOT more to a cam than LSA, and damn the man who passed a long the idea that it is the most significant number involved in cam timing- it is no more significant than duration or lift. They ALL affect the manner of a cam.

 

[tjet]

I want to run the biggest hyd flat tappet cam possible without changing the torque converter or gears. The stall on the tq converter is around 2500. I'd like to install a comp magnum 280H, but I think the 230 dur + the 110 LSA may be too choppy. I'm thinking it may behave better with a 112 LSA

(355, 10:1, Dart 200 heads, Streetmaster intake, Q-jet, Tri-y 1-5/8 headers w/2.5 pipes, 3.54 diff, 3500# truck)

 

[ap72]

I want to run the biggest hyd flat tappet cam possible without changing the torque converter or gears. The stall on the tq converter is around 2500. I'd like to install a comp magnum 280H, but I think the 230 dur + the 110 LSA may be too choppy. I'm thinking it may behave better with a 112 LSA

(355, 10:1, Dart 200 heads, Streetmaster intake, Q-jet, Tri-y 1-5/8 headers w/2.5 pipes, 3.54 diff, 3500# truck)

WTH are you trying to accomplish? Why not just go with a cam that matched your application instead of the "biggest cam I can"?

 

[tjet]

I'm concerned the 10:1 & iron dart heads may cause pinging. I'm thinking 230 & 112 LSA may bleed down some compression

 

[ap72]

I'm concerned the 10:1 & iron dart heads may cause pinging. I'm thinking 230 & 112 LSA may bleed down some compression

Call up a cam company and tell them what you did and tell them you need a way to fix it while giving up as little power as possible. I'd call Isky or Howards or Jones- they're all good at unusual applications.

Also be sure you have 10:1.

 

[vinniekq2]

go to a none flat tappet and or none hydraulic for a smoother idle and more power

 

[tjet]

72 cc Iron eagle 200's, SRP flat-tops #138085 for 6" rods), Felpro 1094 shims

I have the exact same engine in my vette (355 10:1). The only difference is that I'm using Dart aluminum heads, XE268H cam & a 4 speed.

 

[ap72]

72 cc Iron eagle 200's, SRP flat-tops #138085 for 6" rods), Felpro 1094 shims

I have the exact same engine in my vette (355 10:1). The only difference is that I'm using Dart aluminum heads, XE268H cam & a 4 speed.

yep, not 10:1- about 9.6:1 assuming measured volumes are the same as advertised and you didn't take much of the deck.

 

[tjet]

... I'd call Isky or Howards or Jones- they're all good at unusual applications.

Forgot about howards - will check.

 

[tjet]

Try this cam. Comp cams Dual energy 275DEH-10 it is a much better choice for your truck
and will not cause pinging problems. makes lot of truck torque and power and will work very well with your 2500 stall. You'll like this one.. Ditch the old school obsolete Streetmaster intake manifold.
A modern dual plane manifold will do everything better.

The cam is comp cams part # 12-209-2 275-279 219-229 @ .050" .462-.482 110 lsa

Will look into it. I'd like to stick with a single pattern cam if possible (single pattern has a more old school "rhythmic" sound unlike the dual pattern cams like my XE cam IMO) The streetmaster intake I have on my vette pulls harder than the Weiand 8004 I had on it, plus it has an oil fill tube which is a feature I need. Another intake option I may consider is an Edelbrock C-26 dual quad.

Trying to achive a 60's hotrod look & sound with this engine - it's going in my 59 Chev pickup

 

[ap72]

I'd like to stick with a single pattern cam if possible (single pattern has a more old school "rhythmic" sound unlike the dual pattern cams like my XE cam IMO)

I've heard some strange things on this forum, but never the "like single patterns for the sound" line.

As for the oil fill tube- there are other ways to get oil in an engine.

 

[vinniekq2]

you can tell by the sound if a cam has a dual pattern?

 

[ap72]

you can tell by the sound if a cam has a dual pattern?

no. ain:

 

[tjet]

if you want the real sound of he 60's era you need a solid lifter cam in a wide 114LSA.
use Crane Cams cam #110941 It will have the right sound you want.

Get a dual plane off a old 327 and use a carter carb.
The edelbrock C3BX is right out of that era.
So is the Weiand 8016

The Street master is a 70's disco era intake manifold.

60's was solid lifter cams dual planes and dual quads.

You will need to recuve the distributor. bigger valve lash ='s more 60's era solid cam sound.
smaller valve lash ='s rougher idle.
do not go looser on the valve lash than +.006" looser
than the crane cam card spec. you can go up to .012" tighter on the lash.
the lash spec is .022" hot. so,,, you can vary that from .028" to .010" and get a different sound from the cam.
This will not harm the cam or your motor. but will adjust the idle sound to your liking.
adjust the valve lash once a year.

Cool - thanks for the tip on the old school intake & cam :thumbup:

 

[tjet]

Just to follow up, I got a reply from Comp Cams about getting their 280H Magnum with a 112 LSA ISO 110:

Tracey, we can help you with this for sure. We can grind that on what
ever LSA you would like. The 112 LSA will smooth the idle out a little...
And push the power band to the higher RPM side. It will also lessen the detonation threshold.

How much RPM are you looking for? Let me know and we will go from there. Thanks.


Please use the "reply" button so that I can keep track of the
conversation.

[name removed]
Technical Consultant

COMP Performance Group™
3406 Democrat Rd.
Memphis, TN 38118

 

[vinniekq2]

did you talk to Ryan Hart at comp?He takes awhile to respond,,,

 

[techinspector1]

Strange deal, Streetmaster intake with 200cc heads?????
I've used a Streetmaster in the past. They are excellent for idle to 4000 due to the tiny little runners, but run out of breath up in the range. It's almost like the manifold will be signing off right when the heads begin to come on.

 

[AutoGear]

Ive seen a couple non airgap RPM manifolds modified for a fill tube with the EGR in the tube (I think). Cool deal. I'd use a 300-36 manifold and a Holley. Or go Dual Quads. The 60s are my favorite era for Hot Rodding. You went from 283s to 350s; dual quads, tri-power, superchargers, turbochargers...Its wide open. That street master has to go though. As far as the cam; Im a UDHarold fan, or Id call Isky but thats personal preference. Dont forget the CherryBombs!

 

[vinniekq2]

Ill take that street master intake. Like tech said,its great low rpm intake,my choice for mileage builds. not my choice for power