[grivera]

Looking for the ideal HR cam recommendation.

My goal is a 550+ hp street car that can be driven anywhere within reason, NOT a daily driver. I’d like it to be well into the 11s. Pump gas friendly - 93 octane is highest available in my area. Ideally enough vacuum for power brakes but I’m not opposed to adding Hydroboost.

What I have on hand:

1966 Lemans, full street trim and interior, flat hood.

455 .030 short block in chassis with 4.21 crank, h-beam rods, pistons have 4-5 cc valve reliefs and are about .014 below the deck

Dougs headers with a 3” exhaust all the way to the tails and electric cut outs

TH400 transmission- converter not purchased yet

Gear vendors unit installed

12 bolt posi with 3.90 gears

I have two sets of heads on the shelf:

KRE 310 cfm 85cc D Ports, set up for 1.65 rockers and .650 lift - KRE says springs are 1.85-1.875 install height with 135-145 on seat and 370-390 open pressure. I don’t have the port size on these heads off hand but can measure later and advise.

KRE 85cc D Ports, un-ported, intake ports matched to RAIV gasket size

Comp Cams KRE 242/248 (XFI Lobes)

Intake: 292 adv** 242 @ .050**.365 lobe lift

Exhaust: 300 adv*** 248 @ .050* .,362 lobe lift
113 Lobe sep

Comp cams hydraulic evolution roller lifters

KRE Northwind intake, as cast

Torker II intake, as cast - will port match to heads

Harland Sharp 1.65 rockers

Scorpion 1.5 Race Series rockers

Holley 850 Double Pumper 4781-5

Based on the Wallace compression calculator I come up with about 10.25 compression.

I’m open to having the heads surfaced to bump up the compression if need be, but of course working with what I have will be easier.

The original Old Faithful comes to mind for me - it’s a 236/245 duration, .570/.574 lift (magnum lobes).

[PunchT37]

That OF cam is not a bad idea for what you want. It didn`t get it`s name for nothing.

[tom s]

Run the 242-248.Tom

[grivera]

Originally Posted by tom s

Run the 242-248.Tom

Not sure if my compression is up to the challenge with the 242/248 as I don’t want it to be unnecessarily soggy on the bottom end. I emailed KRE and waiting on their reply/suggestion with that cam. If they don’t respond I’ll ask them at Norwalk this weekend.

As much as I’d like to save the money by using what I have on hand, I don’t want to have a regret over saving $500

[Steve C.]

Stated- " I'd like it to be well into the 11s. "

Do you have a estimated race weight with the combo ?


.

[i82much]

i would run the cam you have with the 1.65 rockers, t2 with open or tapered spacer, and a vacuum canister.

i am not an auto trans guy but i would imagine if you err toward a looser converter, you can run a higher idle rpm to get a little more vacuum out of it. an rpm intake might help with low end signal as well.

[Formulajones]

The 242/248 works fine with that compression. My 454 is 10.2 with that cam and made 608/589 with a 305cc intake runner AFR head and makes more torque than a 275 can handle. Rolling 50 mph burnouts weren't a problem. It ran 11.40's at 118 and weighed 4,120 lbs

If you listen to a lot of others they'd tell you those heads were too big for a 454 and won't make torque. That was total bs. It ended up being a nice head cam package and a sweet street engine on what I consider a smallish engine these days and ran on 91 no problem at all.

[Steve C.]

Keep this in mind regarding the solid roller lobes mentioned here, that and the race weight involved. Knowing If you want the valve lift curve to be the same as a hydraulic cam, the solid (Mechanical) lifter cam will be bigger at .050" lift.

If it helps, a friend here in town had a '64 Tempest at about 3500 lb race weight that ran a 10.46 at 127.59 mph. He had a .030-over 455 combo with KRE "310 cfm" Edelbrock heads at the time (72cc castings), Victor intake with a Barry Grant Gold Claw carb (975 cfm) and it had a Comp Xtreme Energy 248/248 at .050 solid roller. Gears were 3.89 with a Huges 10" converter that was about a 3500-plus stall.

Later he changed back to a STREET set up. He put on 87cc Edelbrock heads for use with pump gas, they had a very mild port job by Butler with 299 cfm at .600 lift, and with a nice size 222 cc intake runner volume for the street. Then he put on a Performer RPM intake and removed the larger sleeves for less air flow on his Barry Grant Gold Claw carb. Then he changed to a small Comp Cams Xtreme Energy SOLID street roller with 242/248 at .050 lift . He took the car to the track and ran 11.13 at 121.2 mph in the 90 degree heat with this new street combination.



.

[JB Eng Wis]

I would keep your XFI cam.... and Bump your Compression to around 11 to 1 ,,,, IMO

[besserspat]

Not yo hijack this thread but related

I have a mild KRE XFI HR 232 -238 and it has those baby lobes too.

I mean is there a reason why KRE seem to like small lobe lift compared to many other cams that will be in the .380- 385
lobe lift for similar duration and ramps that are not as aggressive.

I have a Comp SR 245 245 .400 110 LSA lobe lift. ( magnum lobes) On the shelf now but wanted a baby cam for driving around the 461 so Ill run the 232 238 112 HR XFI with 1 65s. but was curious about the low lobe lifts.

Maybe KRE keep low lift to avcomodate the stockish iron D port crowd

Peter?

[grivera]

Originally Posted by Steve C.

Stated- " I'd like it to be well into the 11s. "

Do you have a estimated race weight with the combo ?


.

I don’t have the weight yet, I’m sure the aluminum top end alters factory weight but maybe off set by the TH400 and the Gear Vendors

Originally Posted by i82much

i would run the cam you have with the 1.65 rockers, t2 with open or tapered spacer, and a vacuum canister.

i am not an auto trans guy but i would imagine if you err toward a looser converter, you can run a higher idle rpm to get a little more vacuum out of it. an rpm intake might help with low end signal as well.

I’d like to avoid a vacuum pump if possible, not sure if the RPM intake will work Ok with the flat hood

[i82much]

Originally Posted by grivera

I don’t have the weight yet, I’m sure the aluminum top end alters factory weight but maybe off set by the TH400 and the Gear Vendors



I’d like to avoid a vacuum pump if possible, not sure if the RPM intake will work Ok with the flat hood

not a pump, just a reserve canister:

https://www.jegs.com/i/JEGS/555/6301...caAuGPEALw_wcB

[grivera]

Interesting re: vacuum canister…

I assume all would suggest the Torker 2 with a spacer vs the Northwind?

[ta man]

Originally Posted by PunchT37

That OF cam is not a bad idea for what you want. It didn`t get it`s name for nothing.

You could run low 11's and 87 octane with a cam similar to the OF grind with your compression and have about 13 to 14 inches of vacuum.

[grivera]

That would be ideal - Is the OF designed with headers in mind? Also, what is your combo’s compression and what carb and spacer are you using?

[tom s]

I ran the 245-252 Magnum lobes with 10-1 and made close too 600 HP with the Bathtub intake.The smaller you have will work fine.The engine is now in a 70 GTO with a auto and drives fine.Tom

[grivera]

What size engine was that Tom? How were the street manners?

[tom s]

400 block with a 4.21 stroke crank.It was on a 110 and the guys wife drives the car.And to refresh it was 10.25 CR.Tom

[Formulajones]

Another combo with the same compression you're looking at but an even bigger cam was dad's old 455 combo. Eddy round ports that Kaufman ported to 330 cfm, 10.2:1 compression and Jeff Kauffman spec'd a hydraulic roller with 254/262 @.050 and over .600 lift. That engine pushed dad's goat to mid 11's at around 116 mph and his car at the time was almost 4200 lbs race weight. He drove that for years on the street and was strictly a pump gas engine.

Kauffman spec'd that cam on a 110 LSA

[grivera]

Thanks - does the lower compression work better with the 110 LSA vs the 113 in my HR242 cam?