[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.

[Steve C.]

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

Do you have a estimated race weight with the combo ?


.

[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.

[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

[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.



.

[OCMDGTO]

Run what you have Will!!

[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

[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]

Interesting re: vacuum canister…

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

[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?

[ta man]

Originally Posted by 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?

My old combo was 10.25 to 1 for compression with a 950 Holley HP torker 2 and a one inch spacer

[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