Time for a Cam Change?
 

Since I had great on track results with my converter change discussed in the link below, I would value some thoughts surrounding a potential cam change.

My 236/246 "old faithful 2.0" from Dave is a great all around cam, but since I have manual brakes and am only doing short trip/local street driving I am thinking something a little more aggressive might be fun and bump the ET up a little.

As noted in my sig, heads flow about 310cfm through 1.75" headers and 3" exhaust with cutouts for the track.

Currently running crower solid roller lifters and 1.65 rockers so I could go with a solid roller profile or another hyd profile.

Dave is getting his dyno setup and will be doing more testing, but curious what suggestions some of you may have based on past experience? My goals would be a 20+ HP gain otherwise not worth taking things apart :)

For reference, here is the previous converter discussion and results...

https://r.tapatalk.com/shareLink/top...ink_source=app

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How much lift does your current Cam have and what’s do the heads flow at what lift points ,like might you have a flow sheet you could post up?

To pick up 20 hp overall would mean gaining 2.5 hp per cylinder, and that would take 8 to 10 additional intake cfm per cylinder then the amount of lift your accessing now.
Also now that I looked over your current build, if your T2 intake has not been ported then that intake is strangling your 305 cfm heads.

Also what do you mean by your comment “ might be fun”?
Your already turning low 10s with the car now, so how much faster do you have to go to have as you say , fun,? Lol!

Those intakes in stock form only flow 260 to 265 cfm on my flow bench, so reworking that intake is worth way more then the 20 hp your looking for from a cam swap!

Unfortunately I do not have the flow sheets. Cam lift is 645/660 with the 1.65 rockers.

SD did cnc match the torker2 intake ports to the heads, but to my knowledge they did not do any significant internal porting. I do recall TA Man saying he found decent gains when custom porting his T2 on a similar engine combo. It would definitely make sense to check into.

I cannot see my signature from here, but did find slightly better ET when moving from a 1" open to a 2" open spacer on the T2.

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"Your already turning low 10s with the car now, so how much faster do you have to go to have as you say , fun,? Lol!"

If 10.4 is fun, then 10.3 has to be "more fun" lol. Quite honestly, the current cam makes a good sleeper- I would not mind if it had a little more attitude for the occasional "dairy queen run". But of course performance is the primary objective while staying within the 10.0 roll bar rule.



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The transition formed in the roof in that intake from the end of each the runner into the plenum can be made into a much better flowing bigger radius , especially since you are using a 2” spacer,

Sooner or later the "Road Paver" will pop up in conversation. Not as a recommendation for it's use but as information and for conversation to compare with a similar dyno tested combination...

.030-over 455.
4.250 stroke.
6.8 rods.
Road Paver hydraulic roller cam ( Comp lobes 3115B & 3116B ).
With Crower solid roller lifters.
KRE 300/305 cylinder head package by Dave Bisschop/ 2.110" intake / titanium retainers / about 10.5 compression ratio / 1.52 rocker ratio.
Torker II intake with CNC port match to the heads/ HP950 carb w/ 1-inch carb spacer.
Headers.

Engine made peak power at 5800 rpm on the dyno/589.7 hp
Peak torque at 4700 rpm / 593.9 ft.lbs. TQ



.

WOW, I though most of these combo's ran low 11's to high tens. I am impressed with the mid 10's.

What about a Voodoo 243/251?

Look at the SR cam in my sig, not that big but my 3550# car goes 10.01 with it.

Curious what do your heads flow?

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Steve,that was going to be my suggestion.Bad ass cam.Tom

Steve what is the lsa on that cam?

Scott65, I have copies of Dave Bisschop flow sheets on the heads and dyno sheets for that specific combination I mention. But in my notes I failed to jot down the specific LSA, that said I highly suggest it has the same 112 LSA typically used for the Road Paver cam. All the specs for it have been posted on many occasions.

Road Paver:

.006- 306 / 314
.050- 246 / 252
.200- 164 / 169
112 LSA
.4000" lobe lift
86 degrees overlap

A alternate that might be considered...

QXI lobes 13456 / 13459

.006- 299 / 305
.050- 247 / 253
.200- 168 / 174
112 LSA
.3999" lobe lift
78 degrees overlap
.

Thanks Steve. I know it usually has a 112, but people do move it around. I'm looking at moving closer to 112 and wanted to verify.

I was originally thinking an upgrade to the road paver would be a reasonable option, but from Dave... "the OF 2.0 cam makes more torque and hp than the “Road Paver” "

Of course this discussion was in the context of my gearing and current combo.


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They are Kaufmann 72 cc (actual volume is 73 cc) CNC that flow 335 cfm at 28".

The cam is a CC, 1465/4878R 110+4

The cam I bought for my Ali motor is: 3123B/3116B with a 112° LSA

That is pretty good flow. I think my 305/310 flow numbers will be the limiting factor with my cam selection.

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335 cfm is at 0.700" lift, flow is probably closer to 330 cfm at my cam lift.