Summit CT-101 / Elgin 1091p

[crawdaddy_johnson]

Summit CT-101 / Elgin 1091p
256/264@ 0.050, 105 LSA, .504/.504 gross lift (.026/.026 lash)

Has anyone here run this cam in a hot street car with 4.10 gears and a 4 speed?
I'm thinking about putting it in a budget 406sbc with -416 305sbc heads, with dish pistons will be right at 11:1 compression

listening to videos on youtube, the idle doesn't sound all that crazy
Previously in this engine I've run the isky oval track hyd 244/244@0.050 on a 106 lsa, but looking for a little more midrange grunt.

Thanks!

[mag2555]

If you want more overall torque then lift wise I would run something that leaves with more like .550” lift after lash.

[Tom68]

Stick with the 244 and put heads on it.

[Baprace]

Stick with the 244 and put heads on it.

I agree with Tom68 , that size engine needs heads first , the extra cam won't help very much with 305 heads

[F-BIRD'88]

I'd use Summit CT-108 cam Unless the 305 heads are generously ported its going to be very limited either way.

[F-BIRD'88]

If you want "more midrange" use a dual plane high rise intake manifold.

[crawdaddy_johnson]

I'd use Summit CT-108 cam Unless the 305 heads are generously ported its going to be very limited either way.

The heads do have a home porting job, attached some pictures. yes the ct-108 is another cam I was looking at as well. I appreciate the advice

[F-BIRD'88]

When I do these heads I just drill and roll pin the stud bosses.
Might check the cam phasing to be sure it is "advanced" if it was not degreed in when installed. It may be "straight up" 106/106 in/ex centers. Some of the Isky cams do not have the cam advance ground in when made.

[F-BIRD'88]

Those twinned exhaust port egr/heat riser passages need to be block where they join to stop the center exhaust ports cross talk. This improves header exhaust scavenge , increases torque. I stuff these with balled up thick heavy duty aluminum foil. cut up dollar store aluminum baking/catering pan. Stuff it in tight to block the twinned passages. If it has a single plane intake change to a RPM dual plane.

I doubt a stud girdle itself will stop pulled pressed in rocker studs.

[crawdaddy_johnson]

When I do these heads I just drill and roll pin the stud bosses.
Might check the cam phasing to be sure it is "advanced" if it was not degreed in when installed. It may be "straight up" 106/106 in/ex centers. Some of the Isky cams do not have the cam advance ground in when made.

Yea I plan to drill + pin. I read up on your old post about these heads - you got some impressive times out of them for sure

[1980RS]

I've run the 1090 and 1091 Egin cams before and they both worked great. I think the both have the same duration but one has more lift then the other.

[F-BIRD'88]

Could you better express and define which part of the power band you want to see an increase output at?
What are the valve sizes on those 305 heads. They look small. (1.84"x1.50").
The summit CT-101 is going to add top end power 4500++rpm mostly VS your current cam.
But if the heads are chocked up it won't be realized. ( Having done these heads numberous times I know there is a critical area(s) deep in the port that need addressing to open up the Minimun cross sectional area. "opened up". This is critical to both HP and TORQUE. Especially on a hungry 400 cid SBC. I'll bet that revisiting your heads can buy big gains.
I don't think your compression ratio is near as high (11:1 cr) as you think with 400 dish pistons and those heasds (58-60cc).

Intake manifold is...________.

I used the high lift version .537 .557 of that 256/264 106LSA solid cam on a 350 with ported 4416 heads (1.94x1.60) at a true 12.65:1 cr.
It was all top end ( relative) In that motor in the car #3530 4.10's 3600 10"B&M stall big single plane ( strip dominator) I believe
I would have done slightly better using the smaller CT-108 cam. The big 256/264 cam would have wanted more gear 4.56 and a racing converter 5000 stall+/-. It was strong but I believe these changes would have made in stronger overall. On the street..

4.10's 3600 stall 248/254 106 lsa or a crane "saturday night" 244-252 106 cam (isky 201524 or #201534) and a dual plane RPM with a spacer. (More torque right at the 1/4 mi. launch (3600 stall speed)

On the cam I believe (Mike Jones) Cam King (Jones Racing Cams) has beauti SFT cam lobes right there, for this.
Does not cost you a dime to consult him in this and you ARE ensured of a high quaility product (camshaft and "Centra - Lube" lifters) VS a Elgin-Summit cam. I'd hear him out first before hitting the switch.

[crawdaddy_johnson]

Could you better express and define which part of the power band you want to see an increase output at?
What are the valve sizes on those 305 heads. They look small. (1.84"x1.50").
The summit CT-101 is going to add top end power 4500++rpm mostly VS your current cam.
But if the heads are chocked up it won't be realized. ( Having done these heads numberous times I know there is a critical area(s) deep in the port that need addressing to open up the Minimun cross sectional area. "opened up". This is critical to both HP and TORQUE. Especially on a hungry 400 cid SBC. I'll bet that revisiting your heads can buy big gains.
I don't think your compression ratio is near as high (11:1 cr) as you think with 400 dish pistons and those heasds (58-60cc).

Intake manifold is...________.

I used the high lift version .537 .557 of that 256/264 106LSA solid cam on a 350 with ported 4416 heads (1.94x1.60) at a true 12.65:1 cr.
It was all top end ( relative) In that motor in the car #3530 4.10's 3600 10"B&M stall big single plane ( strip dominator) I believe
I would have done slightly better using the smaller CT-108 cam. The big 256/264 cam would have wanted more gear 4.56 and a racing converter 5000 stall+/-. It was strong but I believe these changes would have made in stronger overall. On the street..

4.10's 3600 stall 248/254 106 lsa or a crane "saturday night" 244-252 106 cam (isky 201524 or #201534) and a dual plane RPM with a spacer. (More torque right at the 1/4 mi. launch (3600 stall speed)

On the cam I believe (Mike Jones) Cam King (Jones Racing Cams) has beauti SFT cam lobes right there, for this.
Does not cost you a dime to consult him in this and you ARE ensured of a high quaility product (camshaft and "Centra - Lube" lifters) VS a Elgin-Summit cam. I'd hear him out first before hitting the switch.

Thanks for the detailed response.
In terms of power band, 4000-6000 is where I want to see better power, I probably won't rev it any higher than 6500.

Valve size is the stock 1.84 x 1.5, but they are new Elgin valves.

My dished pistons are 12cc SpeedPro's, with a .005" deck clearance and .039" gasket, which is where I got the 11:1 ratio from (still could be off somewhere in my calculation)

Intake manifold is a Performer RPM knock-off, plenum cut down with 1/2" open spacer, with a 750 annular-booster carb from a builder in PA.

[F-BIRD'88]

I'd say its the heads that are the cork in the system. U did a nice job on what you did but they really need bigger valves (1.94x1.60 at least) and full effort porting to match. These 305 heads really need opeining up to get them to flow. 2.05"x1.60 valves even better.
You'll have tro decide if you want to invest more $$ and work in these heads but as of now I believe this is the major cork in the air flow chain on this engine. The cam and possibily a single plane intake will help some but the gains are limited by these heads in their current form.
This 400 SBC is hungry for air flow HA HA.
Remember if you swap to a single plane you will gain a bit of top end ( above 4000 rpm) but trade off some low end midrange street torque.
Be prepared to put the dual plane back on...
Again IMHO haviong been there on this It will be limited (HARD) by the heads right now.

[crawdaddy_johnson]

Fair enough! I'm tempted to pick up a pair of TFS 195cc "super 23" heads currently on Marketplace, seller is asking $1400 and they look almost new. In your experience, how dramatic a change was there when switching from stock iron heads to aftermarket aluminum? Is the performance night and day?
I got my car out of storage yesterday and like you said I sense that it wants more air and possibly more cam.