360 cam question...

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'66Cuda

'66Cuda

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Kansas
Car specs:
1966 Barracuda, 360 .030 over, Keith Blacks flat tops, Holley 650 DP, 727 auto, 8 3/4 sure grip, 3.55 gears - intended use is primarily street.

I measured my cam lift today with my dial gauge. I got an average of .279" intake and .294" exhaust of dial lift. Using the stock rocker arm ratio of 1.5, I get .418 intake valve lift, and .441 exhaust valve lift. I have no idea on the duration. So this is probably not the performance cam I am looking for to take advantage of some 2.02 J heads with some porting. I am considering the Summit cam kit 285/285 .480/.480 as its reasonably priced and approximates the 280/.474 cam in the 360 Stage 3 build found in How To Hot Rod SBM's . I plan on using stock manifolds due to the header issues that plague the early A bodies. I believe they are the original 273 manifolds.

What are your thoughts on the cam choice I am considering? What will its manners be? Is there a better choice considering I am using stock manifolds? Anyone have any experience with Summit cam quality? I know I will leave some HP's on the table not going with headers. But $1500 for headers and their relatively minimal gains puts them out of reach at the moment, due to other areas of the vehicle I am restoring.

Thanks
 
You'll love the chop chop and Proformance. it will be a little difficult to hold back at the light without a stall converter or 4 speed
 
I would go with the lunati voodoo 262. works awesome with manifolds! has muscle car sounding idle, and it very streetable. pulls hard, lots of low and midrange torque. Heck i just put one in my chebby work truck 350 sb ( I know apples, oranges), stock converter, 373 gears. I think its just as streetable as a stock cam and passes emissions with flying colors! Sheesh im starting to sound like a lunati salesman.
 
moturbopar said:
I would go with the lunati voodoo 262. works awesome with manifolds! has muscle car sounding idle, and it very streetable. pulls hard, lots of low and midrange torque. Heck i just put one in my chebby work truck 350 sb ( I know apples, oranges), stock converter, 373 gears. I think its just as streetable as a stock cam and passes emissions with flying colors! Sheesh im starting to sound like a lunati salesman.
Click to expand...

Excellent choice...
 
I forgot to put down I will run a 2200 stall converter.

TTI's are $950ish to my door. $300 for a clockable mini starter. Then whatever it takes to plumb it in.
 
'66Cuda said:
I forgot to put down I will run a 2200 stall converter.

TTI's are $950ish to my door. $300 for a clockable mini starter. Then whatever it takes to plumb it in.
Click to expand...


Those will work also, but only go in 2° increments. The keys go 1° increments...

Depends on what you need.... :glasses7:
 
'66Cuda said:
Car specs:
1966 Barracuda, 360 .030 over, Keith Blacks flat tops, Holley 650 DP, 727 auto, 8 3/4 sure grip, 3.55 gears - intended use is primarily street.

I measured my cam lift today with my dial gauge. I got an average of .279" intake and .294" exhaust of dial lift. Using the stock rocker arm ratio of 1.5, I get .418 intake valve lift, and .441 exhaust valve lift. I have no idea on the duration. So this is probably not the performance cam I am looking for to take advantage of some 2.02 J heads with some porting. I am considering the Summit cam kit 285/285 .480/.480 as its reasonably priced and approximates the 280/.474 cam in the 360 Stage 3 build found in How To Hot Rod SBM's . I plan on using stock manifolds due to the header issues that plague the early A bodies. I believe they are the original 273 manifolds.

What are your thoughts on the cam choice I am considering? What will its manners be? Is there a better choice considering I am using stock manifolds? Anyone have any experience with Summit cam quality? I know I will leave some HP's on the table not going with headers. But $1500 for headers and their relatively minimal gains puts them out of reach at the moment, due to other areas of the vehicle I am restoring.

Thanks
Click to expand...
If you have a Hyd. cam in the engine now, you readings are inaccurate because of the lifters. There not solid to give an accurate reading.
The Summit cams are made by Crane Cams for Summit. So quality is not an issue.
Choose a cam via it's duration for the rpm you will cruise in. Match it with the torque converter.
IMO, a cam with more exhaust duration should be used since you are going to use exhaust manifolds which are restrictive vs headers.
This will allow the engine to breath better and the extra exhaust duration will extend the rpm band of the cam.
That cam is only similar to the stage 3 build you looked at but it is not. It is a mello'er cam.
 
'66Cuda said:
Car specs:
1966 Barracuda, 360 .030 over, Keith Blacks flat tops, Holley 650 DP, 727 auto, 8 3/4 sure grip, 3.55 gears - intended use is primarily street.

I measured my cam lift today with my dial gauge. I got an average of .279" intake and .294" exhaust of dial lift. Using the stock rocker arm ratio of 1.5, I get .418 intake valve lift, and .441 exhaust valve lift. I have no idea on the duration. So this is probably not the performance cam I am looking for to take advantage of some 2.02 J heads with some porting. I am considering the Summit cam kit 285/285 .480/.480 as its reasonably priced and approximates the 280/.474 cam in the 360 Stage 3 build found in How To Hot Rod SBM's . I plan on using stock manifolds due to the header issues that plague the early A bodies. I believe they are the original 273 manifolds.

What are your thoughts on the cam choice I am considering? What will its manners be? Is there a better choice considering I am using stock manifolds? Anyone have any experience with Summit cam quality? I know I will leave some HP's on the table not going with headers. But $1500 for headers and their relatively minimal gains puts them out of reach at the moment, due to other areas of the vehicle I am restoring.

Thanks
Click to expand...

66 Cuda,

The Camshaft that you spec'd out sounds like a Summit #K6900
Lift....................... .421"/.444"
Duration................ 278*/288*
Duration @ .050" ... 204*/214*
LSA ...................... 112*

* That's a Low-End Torque-Puller, good for {1200 to 4800 RPM's}.
* With a smooth-idle, and good Low-End Horsepower and Torque.
* A good application for a Heavy Car, RV Vehicle, and/or Towing.
-------------------------------------------------------------------------------

Regarding the quality of the 'Summit' Camshafts. They are out-sourced,
but are fine for 'general performance', and priced accordingly.

The SUM-1798 {$101.97}
Lift...................... 480"/.480"
Duration ............. 285*/285*
Duration @ .050".. 228*/228*
LSA..................... 112*

Has been proven as a decent High-Performance Street Camshaft.

The idle is a little 'rough', but it has excellent Mid-Range Power,
especially from 2500 to 6000 RPM's.

Not the best choice with Stock '273' Exhaust Manifolds though.

With the 2200 RPM Stall Torque-Converter, you are right on the edge
with this Camshaft.
 
rumblefish360 said:
If you have a Hyd. cam in the engine now, you readings are inaccurate because of the lifters. There not solid to give an accurate reading.
The Summit cams are made by Crane Cams for Summit. So quality is not an issue.
Choose a cam via it's duration for the rpm you will cruise in. Match it with the torque converter.
IMO, a cam with more exhaust duration should be used since you are going to use exhaust manifolds which are restrictive vs headers.
This will allow the engine to breath better and the extra exhaust duration will extend the rpm band of the cam.
That cam is only similar to the stage 3 build you looked at but it is not. It is a mello'er cam.
Click to expand...

I measured the actual lobe through the lifter valley. What am I missing with the lifters?

I share the same concern with needing longer duration on exhaust, because of the stock manifolds, but am not sure how big of a problem it might actually be. That is why I was looking for someone else's opinion. How much exhaust duration do you consider sufficient?
 
69 Cuda 440 said:
66 Cuda,


The SUM-1798 {$101.97}
Lift...................... 480"/.480"
Duration ............. 285*/285*
Duration @ .050".. 228*/228*
LSA..................... 112*
Click to expand...

X2 on that cam. Also take a look at the Crane Cams 693801.


Duration: 222 int. / 234 exh.

Valve Lift: .467 / .494 lift

Lobe Separation: 114



Also, why the 2200 convertor? That is very tight. I run a 3500 and it's like nothing at all. My car does 99% street use. It only foot brakes to just over 1,000. VERY efficient. I'd go at least 3000 on that convertor if I were you. Just make sure you tell them the intended use and don't' go OTC for your convertor.
 
roccodart440 said:
X2 on that cam. Also take a look at the Crane Cams 693801.


Duration: 222 int. / 234 exh.

Valve Lift: .467 / .494 lift

Lobe Separation: 114



Also, why the 2200 convertor? That is very tight. I run a 3500 and it's like nothing at all. My car does 99% street use. It only foot brakes to just over 1,000. VERY efficient. I'd go at least 3000 on that convertor if I were you. Just make sure you tell them the intended use and don't' go OTC for your convertor.
Click to expand...

As with so many things in life, its what I have. 3500 seems high for a street machine, no? What are your cruise RPM's?
 
'66Cuda said:
I measured the actual lobe through the lifter valley. What am I missing with the lifters?

I share the same concern with needing longer duration on exhaust, because of the stock manifolds, but am not sure how big of a problem it might actually be. That is why I was looking for someone else's opinion. How much exhaust duration do you consider sufficient?
Click to expand...

Sorry, did you measure the actual lobe lift?
I thought for some reason you may have measured the cams lift with the Hyd. Lifter on the cam. The lifters design has moving parts that go up and down with oil pressure. Since you have no oil pressure the lift would be greatly reduced.
 
'66Cuda said:
As with so many things in life, its what I have. 3500 seems high for a street machine, no? What are your cruise RPM's?
Click to expand...

I cruise around 2400-2600RPM.

3500 is nothing by today's standards and modern convertor technology. Like I said, mine flashes to 3500 but will only foobrake to just over 1,000. It's very efficient. Great for the street. Ok, for the strip. I'm leaving a lot on the table.
 
UPDATE:

I pulled the head and found I am .060" over and not .030", like I was told. I measured my deck height at .062" in the hole and CC'd my 915 J heads at 74 cc's on one side and haven't done the other yet. My pistons, from the top side, look like speed pro's with 4 valve reliefs, which increases combustion volume by 10 cc's, according to Summit website. These measurements put my compression at a lowly 8.2:1. I am changing the valves to nailhead style, which will give me back 3 cc's, maybe. That makes almost 8.3:1. With this low compression I need to back down on my cam choice. I am now considering the XE268h that is a popular suggestion on FABO, as well as the Summit 1789 (272/.454 - 216/216 @ .050). I would estimate my port job on my heads as more than average. I am considering a 3000 stall now as well. Opinions?

Does that much overbore have any effect on cam choice?

Thanks!
 
you have to measure hydro lifters using the edge of the lifter (or seat with no valve contact) as they squeeze under valve spring pressure when they are not pressurized. When they are pumped they act just like a solid.
 
The Comp cam is 8*'s bigger than the Summit can. The recommended stall converter min. Is 2000 for the Comp cam. *I think* 3000 might be a bit much for the Comp cam much less for the Summit cam which does not require a stall converter.

The Summit cam is a good basic 4bbl. cam.
The Comp cam which I would say would be fine to use is a good step up and in the right direction. The only head work to be done at most really is a bowl porting. Since you have the 2.02's in a J head now, IMO, your in good shape.
 
Built a motor with those pistons for my brother very similar to yours.
Summit 480/480 cam
.029 head gasket
ported smog heads MP SS 1.88/1.60 valves
milled heads to 62cc 9.5-1 compression
273 rockers with custom lenght Smith Brothers ball/cup pushrods
airgap/650 demon dp/1 1/2" shorty headers/manual cutouts for the track
2500 stall/904 reg gear set/3.55/QTP slicks 26.5"
93 oct pump gas
3000 lb 66 dart, 12.7, 90* humid FL day. Still needs to be tested for best shift points.
Motor will blow the street tires off at will.

How thick are the head gaskets you removed?
 
Standard blue FelPro. I haven't measured the old one, but .039 is given value. I would like to use that cam, but ny low compression scares me. I feel like I need that big of one to take full advantage of my heads.
 
I have the Comp XE268 in my 69 340 Barracuda. It is awesome. It has a lopey idle, and I can scald the tires. This cam plus headers, Air Gap intake and new Comp valves are good for 375 HP from a 340.
 
'66Cuda said:
UPDATE:
With this low compression I need to back down on my cam choice. I am now considering the XE268h that is a popular suggestion on FABO, as well as the Summit 1789 (272/.454 - 216/216 @ .050). I would estimate my port job on my heads as more than average. I am considering a 3000 stall now as well. Opinions?

Does that much overbore have any effect on cam choice?

Thanks!
Click to expand...

That's a good all around cam IMO. Run a thinner head gasket to get your compression up a tad. I run the 268 in my stock bottom end 318 and it performs quite well IMO.

IF you are considering dropping the coin on a new converter, wait until you have everything else set in stone, and have one built specifically for your combo. Like I said above, I'm going with PTC, they make a good converter and the price won't break the bank.

The key is, you must be completely honest about all of the engine specs, gearing, tire size, car weight etc. and intended usage.

A good converter will affect the cars performance just like any other aspect of the build.
 
mderoy340 said:
Built a motor with those pistons for my brother very similar to yours.
Summit 480/480 cam
.029 head gasket
ported smog heads MP SS 1.88/1.60 valves
milled heads to 62cc 9.5-1 compression
273 rockers with custom lenght Smith Brothers ball/cup pushrods
airgap/650 demon dp/1 1/2" shorty headers/manual cutouts for the track
2500 stall/904 reg gear set/3.55/QTP slicks 26.5"
93 oct pump gas
3000 lb 66 dart, 12.7, 90* humid FL day. Still needs to be tested for best shift points.
Motor will blow the street tires off at will.

How thick are the head gaskets you removed?
Click to expand...

Did you have to O-ring the heads? Any problems with leaky head gaskets? I would really like to get the compression up to 9:1, if at all possible. If I used your gasket, and milled the heads .024" (.0048" per 1 cc is what I have read?) that would just get me there. Is .024" milling on the heads possible without having alignment issues with the intake, etc.?
 
'66Cuda said:
Did you have to O-ring the heads? Any problems with leaky head gaskets? I would really like to get the compression up to 9:1, if at all possible. If I used your gasket, and milled the heads .024" (.0048" per 1 cc is what I have read?) that would just get me there. Is .024" milling on the heads possible without having alignment issues with the intake, etc.?
Click to expand...

-No O rings needed.
-Any problems with leaky head gaskets? No leakage, but you need to check the block surface for flatness.
-For each .0048" (.005 real world) you mill off, the chamber is reduced 1cc. Be sure to mill the intake surface .0095" for each .010" off the head surface otherwise your intake will not line up and fit right.
-I'm lucky and have a good machine shop locally. I bring them the bare heads and have them milled to a CC# that I want. I've had two sets milled .040 and .045 and have no issues.
-I use the Summit intake gaskets. After the heads are installed test fit the intake.
-valve train geometry will change, adjustable rockers will really be needed and you need to measure for correct pushrod length. Hughes sells rocker shaft shims also.
-Another option if you don't mind a sewing machine sound at lower rpms is to use Rhoads lifters. Using them with an adjustable rocker gives you lower duration and lift below 3000. Lower duration closes the intake valve sooner and keeps the dynamic compression up at lower rpm. Above 3k your back to full duration and lift. Basically you have variable duration cam timing. I have done this before with a low compression 9.1 360 and it pulls like a freight train. The XL lifters have a small groove that also directs oil to the cam lobe. Very good quality lifter and you can buy direct from Rhoads. A lot of people bash them, but they really work good.
http://www.summitracing.com/parts/rhl-2018xl
 
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