anyone with a desktop dyno willing to test 2-cams.

[BSB67]

the comp cam is definitely better all the way around. picked up 1.5 tenths .

Yes!!!! You have track data?

Can you share the details.

 

[PRHeads]

the comp cam is definitely better all the way around. picked up 1.5 tenths .

Was the bullet run with solid lifters set at .014”(as was hand written on the card)?

And the comp run with Hyd lifters at zero lash?

If so, that would result in the comp having some(likely) needed additional seat timing.

 

[gtxrt]

Yes!!!! You have track data?

Can you share the details.

i have G-Tech times I will do a complete post tomorrow on that.

 

[gtxrt]

Was the bullet run with solid lifters set at .014”(as was hand written on the card)?

And the comp run with Hyd lifters at zero lash?

If so, that would result in the comp having some(likely) needed additional seat timing.

yes .014-.015 hot. comp cam .060-.070 preload. I am thinking the bullet cam at [email protected] is really 214 or 215. and comp at 221 @.050 makes comp cam 6* to 7* bigger @.050. that is like moving up a good 1 size bigger camshaft with no loss of bottom end but more power at mid and upper mid range power pulling strong to 5200-5300 rpms.

 

[PRHeads]

The bullet at [email protected] is pretty short to begin with…….then add in the lash and it’s probably down close to 240 net.
Thats short seat timing for a 440.

 

[gtxrt]

when I rebuilt it I put this cam in. it was soft off the line didn't like it even with 2.94 gears it should have been faster so I put the 220-220 cam in and it was still soft with less power in mid upper rpms besides. it was the torque converter I put in it had less stall then the stock one. now I have the right converter in there. I also blamed the 516 heads with 1.74 exhaust valve with port work I bought from someone. I still think sometimes they're not done right.

 

[PRHeads]

Are you running 1.6 rockers?
The lift figure on the card is for 1.6’s.

Too tight of a converter will numb up a combo for sure.
And I believe low stall speeds also(generally) have a lower tq multiplication factor……. So it’s a lose-lose.

 

[PRHeads]

The bullet at [email protected] is pretty short to begin with…….then add in the lash and it’s probably down close to 240 net.
Thats short seat timing for a 440.

Looking at the bullet lobe listings, it would appear the card for the 220/220 cam had an error for the lift point of the advertised duration.
The card shows it as a Hyd cam, but it’s in the solid lifter lobe section……. And that 249 number is for .020” tappet lift, not .006”.

 

[gtxrt]

running 1.6 rockers on all 3 cams. might be a misprint on the cam card. the 220 has more lift than the 225 cam which I liked. also misprint on my part I said 915 heads they are 516 heads.

 

[gtxrt]

not happy with it yet my Newport with the same set up runs 2 mph faster and weighs 400 lbs more and stock 1.5 rocker arms. RT 2.94 gears no headers full tank of gas hot day with 77% humidity. if you think I am making excuses I am. it should be in the mid-high 13's. the g-tech went with me to the drag strip it had the same mph as the track but would read 1 tenth faster than the track times.

 

[BSB67]

The car is beautiful.

I don’t remember the details of your engine and car, but that time and mph is what they did from the factory. Some were slower.

From a previous life. I did run 2.94s in it for awhile. It seemed no different than the 3.23s driving around, but never took it to the track with them

Post Your 13 Second Combos

 

[PRHeads]

the 220 has more lift than the 225 cam which I liked.

In the Bullet lobe listing, the 220 did have more lift than the 225.

Car looks great!!

With equivalent work, I would expect 915’s to be better(in the car) than 516’s…….but probably not better enough to justify the swap.

Do you have to drive it off the line, or can you just floor it without spinning?

 

[gtxrt]

In the Bullet lobe listing, the 220 did have more lift than the 225.

Car looks great!!

With equivalent work, I would expect 915’s to be better(in the car) than 516’s…….but probably not better enough to justify the swap.

Do you have to drive it off the line, or can you just floor it without spinning?

have to ease it out a little. I am going to do another test run because a few days before that it felt like low 13's. i wasn't thinking when I tested that day. have a couple things going on with it. hang on before judgement lol

 

[BSB67]

The 2.02 sixty ft suggests to me that his launch technique is pretty good for a true full-on street tire, his gear and converter.

If the tires break-loose, you’re usually in the 2.4 sec range.

 

[PRHeads]

Stock intake manifold?

Any mods to it?

Where did you run it?
Empire, ESTA, or LVD?

 

[gtxrt]

Stock intake manifold?

Any mods to it?

Where did you run it?
Empire, ESTA, or LVD?

rpm performer, avs2 800 carb, light weight pistons. ESTA

 

[PRHeads]

One reason I asked about the intake is, back when I was doing heads for some of the stock appearing guys I did a bunch of intake flow testing.

You could make some decent improvements to the heads, but after you bolted a stock intake on it, you could lose like 80% of what you gained in the head.

Based on flow bench results, the ootb RPM intake was quite a bit better than reworked oe manifolds.

The point I was getting to is……… if you’re running a stock intake manifold…….. it will negate a lot of improvements done to the heads.

 

[gtxrt]

You could make some decent improvements to the heads,

l bought the heads 10 years ago never really looked them over. I know they have the 1.74 valve and 924 valve springs which I like the 911 spring a lot better. he said the heads were ported but not sure how much. when the intake was off I saw the intake runners they were just machined a little on the bottom no gasket match either. not sure on the bowl area. I bought the car back after 8 years after I first sold it.

 

[PRHeads]

With 516’s, It’s tough to make big improvements in flow, in the lift range of the cams you’re running, without resorting to bigger valves and/or a fair amount of porting.
I feel it’s because of the rather flat floor and low SSR height, which allows the flow column to start skipping across the back of the intake valve at a pretty low lift.
Once that transition happens, flow essentially ceases around part of the perimeter of the valve.

The taller SSR of the 915/906 can delay the lift point at which the transition happens.

 

[gtxrt]

thought i was going crazy made 3 runs all low 14's felt like no power 2 second 60 ft times. going to call it quits but felt like more power on the way back. did one last run the power started coming back. I think because the oil had to warm up well and the intake had to get heat soaked. 15-40 oil. could never get an even 14 and 100 ever again lol.