#21  
Old 07-18-2015, 03:45 PM
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Originally Posted by BruceWilkie View Post
Debs 406 with 69 #46 heads (gasket match bowl blend fitted with 2.11/1.77 valves)
60916 cam 1.5 rockers 1.75 super comps(full flowmaster exhaust) RPM intake 3310(-1)780 @ 9.6 compression. Installed in 69 'bird convertible around 3700+ lbs without driver. 2200 stall convertor t400 and 2.56 gear. Drives nice town or highway, idles near 15" vacuum at 750 rpm yet has a nice performance sound to it. Pulls strong to @ 5200 then levels til 5600 before notably dropping off. Car has gone 8.10's in eigth with tire spinning lousy 2.3+ 60 ft times and has run 13.08 @104+ in quarter. Crosses line in 2nd gear at @5200. (much similar to running a powerglide with 3.78 rear gear)

What I do find surprising is how fast speed comes up relative to engine sound. Big difference over another car I had with 4.56 gears.

The 60916 pulls hard from off idle up. This cam makes great torque and good power. I wouldnt be concerned about dropping back to a set of longbranches though I'd probably change back to stock or performer intake if I did. I doubt it would hurt street performance.
This 400 engine belongs in the 'PY Hall of Fame', that kind of 1/4-mile performance with the tall 2.56 cogs is almost unbelievable. Just a tick away from the 12s, most would need a 3.42 or 3.73 gear behind their 400 to even come close to that 13.08 @ 104+MPH run.

Bruce this is a true testament to your ability to piece together a good combination of parts and more importantly showcases your expert tuning skills.

Wow, I'm impressed to say the least.

Sometimes less is more when choosing cams, converters and rear end gears for a street Pontiac.

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  #22  
Old 07-18-2015, 04:17 PM
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60916 with 1.65 rockers would be a great improvement. Your headers are fine on a 400.

3.23 gears are really a good compromise between performance and freeway driving. Tire diameter will also play a role in how well they work on the freeway. My Formula with 3.23s and 27" tires cruises along just fine at 70 MPH at 3000 RPM and pulls like crazy at those speeds.

Don't be afraid of a good converter with as much as 3000 stall. The key is to spend the money to get one that is very well coupled below its stall speed. I have a Coan "Pro Street" 3000 stall and it drives like stock in normal driving. I never had any problems hooking on street tires.

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  #23  
Old 07-19-2015, 06:51 AM
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Some very helpful information in this thread! I will run 295/50/15" tires, which will be about 26.6" in diameter. Will check some more options about the converter.

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  #24  
Old 07-19-2015, 10:04 AM
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I'll play devils advocate here....after swapping 3 cams on the same 400, I found that the cam alone did not turn my engine from a zero to a hero (meaning after cam change I thought, "wow").....nothing wrong with the crower or the 068, I just wouldn't expect miracles by just swapping cams

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  #25  
Old 07-19-2015, 04:06 PM
BruceWilkie BruceWilkie is offline
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B-man my build is nearly identical specs as the 420 hp 406 pump gas combo KRE offered in their 2002 catalog. Jeff said this was the cam and to degree it at 108 which is what was on timing card. My MPH indicates I'm not making anywhere near 420 hp. (Even if race weight was significantly higher.)
Others at similar weight with similar motor, same cam, have gone 12.60's with traction, better gearing and convertor. I doubt there is 50 hp difference between us though. And fwiw my 3310-1 has been with me since the 70's and has done well even on others vehicles.

  #26  
Old 10-03-2020, 10:18 PM
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did you ever change to the 60916 was thinking to do that my self?

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Old 10-04-2020, 09:02 AM
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I helped a local customer here a few years ago with a near identical combo put his Firebird into the 11's.

His 400 also uses ported iron heads, #62's and just over 10 to 1 compression, 406CID. I rebuilt his TH350 and supplied a custom torque converter for it. We moved up the larger Crower 60243 cam, HS high ratio rockers and Rhoads lifters.

The car runs over 114mph in the 1/4 mile and solidly into the 11's in full street trim on DOT's. The engine is topped with a 1968 cast iron intake and factory Q-jet we prepared here .

He uses 3.73 gears out back. Nothing really fancy with the set-up, no aluminum heads, stroker crank, or roller cam set-up. Just a nice solid 400 build with better rods, pistons, cam upgrade and professionally ported factory iron heads.

For what you are doing the converter will be the single best upgrade to vehicle performance especially with the cam upgrade. I've tested and replaced the GM 20 Hughs stall converter on several occasions here. Behind a 400 build, those converters are not overly impressive anyplace. Replacing them with a custom converter was a HUGE improvement in overall vehicle performance with no loss anyplace in drivability.........Cliff

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  #28  
Old 10-04-2020, 10:11 AM
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I would absolutely go with the Crower 916 over the 068.

My opinion trying to wring all I can out of an 068 is that it's just a small cam and has it's limitations.

Here's my 400 RAIII. All stock, RA manifolds, no porting anyplace, 10.13:1 compression. 068 with stock converter and running 3.31 gears out back. I've pretty much hit a wall no matter what I tweak or tune or change with this thing.

13.10 is the best ET and 104 is it's best mph at a 3890 race weight in the Arizona heat. This particular pass corrects to a 12.76 at over 106 mph.

https://youtu.be/er1z7PpqsnY

Makes decent grunt for a little engine but it's all done at 5,000. It shifts at 52-5300 on it's own. I've tried as much as 5700 and while it doesn't lay over or have a big feeling of power loss, it does nothing for ET or MPH and runs exactly the same. I've squeaked about all it has to offer, I feel it's cam limited and the Crower 916 is certainly a camshaft I would look at for this combo.
Last track outing I even installed an L88 converter that flashes around 2600 rpm. I was expecting improvement but the car again, ran exactly the same. 60 foot hardly changed. Best 60 with stock rubber and original converter is 1.89. With the L88 converter it went 1.91 Just shows this engine being as stock as it is, doesn't seem to care. It needs a cam change!

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  #29  
Old 11-26-2022, 12:28 AM
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Quote:
Originally Posted by Formulajones View Post
I would absolutely go with the Crower 916 over the 068.

My opinion trying to wring all I can out of an 068 is that it's just a small cam and has it's limitations.

Here's my 400 RAIII. All stock, RA manifolds, no porting anyplace, 10.13:1 compression. 068 with stock converter and running 3.31 gears out back. I've pretty much hit a wall no matter what I tweak or tune or change with this thing.

13.10 is the best ET and 104 is it's best mph at a 3890 race weight in the Arizona heat. This particular pass corrects to a 12.76 at over 106 mph.

https://youtu.be/er1z7PpqsnY

Makes decent grunt for a little engine but it's all done at 5,000. It shifts at 52-5300 on it's own. I've tried as much as 5700 and while it doesn't lay over or have a big feeling of power loss, it does nothing for ET or MPH and runs exactly the same. I've squeaked about all it has to offer, I feel it's cam limited and the Crower 916 is certainly a camshaft I would look at for this combo.
Last track outing I even installed an L88 converter that flashes around 2600 rpm. I was expecting improvement but the car again, ran exactly the same. 60 foot hardly changed. Best 60 with stock rubber and original converter is 1.89. With the L88 converter it went 1.91 Just shows this engine being as stock as it is, doesn't seem to care. It needs a cam change!
\\

Did you ever try the 90916 in your car?

  #30  
Old 11-26-2022, 07:43 AM
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I haven't. I still use the car as a daily and have enjoyed racing it in its PS form but honestly I lean more towards building a bigger sleeper engine for it rather than tearing into this engine.

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  #31  
Old 11-26-2022, 09:31 AM
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Quote:
Originally Posted by Formulajones View Post
I haven't. I still use the car as a daily and have enjoyed racing it in its PS form but honestly I lean more towards building a bigger sleeper engine for it rather than tearing into this engine.
Yes, fun to improve but a stroker would make it easier. Just wondered if the 60916 is worth the time and effort.

I'm faced with the same thing. My LeMans is very similar setup to your car. Changing to RA manifolds and pypes system at the moment to improve it.

  #32  
Old 11-28-2022, 08:38 PM
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Quote:
Originally Posted by Cliff R View Post
I helped a local customer here a few years ago with a near identical combo put his Firebird into the 11's.

His 400 also uses ported iron heads, #62's and just over 10 to 1 compression, 406CID. I rebuilt his TH350 and supplied a custom torque converter for it. We moved up the larger Crower 60243 cam, HS high ratio rockers and Rhoads lifters.

The car runs over 114mph in the 1/4 mile and solidly into the 11's in full street trim on DOT's. The engine is topped with a 1968 cast iron intake and factory Q-jet we prepared here .

He uses 3.73 gears out back. Nothing really fancy with the set-up, no aluminum heads, stroker crank, or roller cam set-up. Just a nice solid 400 build with better rods, pistons, cam upgrade and professionally ported factory iron heads.

For what you are doing the converter will be the single best upgrade to vehicle performance especially with the cam upgrade. I've tested and replaced the GM 20 Hughs stall converter on several occasions here. Behind a 400 build, those converters are not overly impressive anyplace. Replacing them with a custom converter was a HUGE improvement in overall vehicle performance with no loss anyplace in drivability.........Cliff
Cliff what are the spec's on that cam you used?

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  #33  
Old 11-29-2022, 10:01 AM
Steve C. Steve C. is offline
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Somewhat related. Old discussion involving the Crower 60243....

http://forums.maxperformanceinc.com/...d.php?t=741658

60243
284/290
228/235 .
.479/.494
112



.

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  #34  
Old 11-29-2022, 10:58 AM
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I ran the 916 in both a 400 and 455 a few years back. Just about right for a mild street car in the 400. A little too small, in my opinion, for a 455.

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