CAM CHOICE
 

Hey guys. I am new here so excuse me if I’m posting in the wrong place. I’m trying to build an N.A street cruiser and want your guy’s input on my build list and direct me in the right direction before I drop this engine in the car soon. I am worried about the cam not being able to make enough power. If possible, would like a low 11 second car, while still having a nice cruiser to daily with the family. Here is what I got so far, ready to go into my roller:
455 H.O, bored and stroked with a butler, forged rotating assembly (474 ci), butler ported, round port 87cc E-heads 325cfm. CNC port matched performer rpm intake, Holley Sniper EFI.
Cam I bought was the BP8041sp
294/300, 242/248, .594/.619, 112LS with 1.65 rockers. Doug’s longtube headers. Took the doug Nash 5 speed out of it to get an overdrive. I’m going with an art carr 200r4 auto (unless you guys have a better alternative by tomorrow)
Bought a moser 9 inch rear, Detroit locker 3.50 Ratio
Also note this is a full interior, A/C car with no weight reduction anywhere. 1969 GTO

Sounds like a nice combo but assuming your car is about 4000 lbs I don’t see you making the needed hp to run something like a 11 30,
Especially with no major chassis improvements!

I am probably going to do a BMR tubular suspension kit. depending on how business goes for me these next few months. I am expecting to be making close to 600 hp.

For a heavy at like a full-weight ‘69 GTO I’d be looking at a more robust 4L80E rather than the somewhat questionable 200-4R.

You’re asking a lot to run low-11s in a street driven car like that. We’re talking 3900 pounds without the driver.

If I was doing something like this I’d be running an aftermarket block with 500+ inches and a 260 degree cam to make a solid 600 horsepower without having to over stress the factory block with high rpms. Cubic inches are your friend especially on the street, those additional cubes will soak up a long duration cam and make it easier to drive.

Your 474 needs a bigger cam and a converter that stalls high enough to take advantage of it.

When you already bought most of the parts it’s hard to recommend just a cam that’ll get you there that you also already bought.

If you’re more into street driving than hitting the track to get a few time slips I’d really think hard before going automatic. Being a stick shift guy you might regret going to a high stall automatic trans, it won’t have the same fun factor as a stick. There are nice overdrive 5-speeds out there that might be worth considering.

I didnt want to go with an electronically shifted tranny. The 200-4r i am getting is an art carr unit from california performance. theyre supposedly good for up to 750 hp. I know im asking alot. I dont want to be too unrealistic. I spent enough cash as is but will spend a little more to try and reach my goal. A similar build with a similar cam made 578 hp with a 850 edelbrock carb, so i think i should be close to 600 when everything is said and done. I just wish i knew more about camshafts before placing that order. I just feel like im leaving some hp on the table with my cam and possibly the intake too. My engine builder felt better about using the performer versus a torker 2

Performer intake ? Not the Performer RPM ?

The Torker II would be a better choice than either one of or those, a single plane runs fine on the street on a 455+ cube engine.

There are plenty of other single plane intakes as well that are more suited to 600 horsepower engines. A dual plane intake would not be on my list.

it is the performer rpm from butler, cnc port matched to the heads.. My mistake for not being specific.

I now regret selling that doug nash. Considered going with a tremec tkx. Wife says she wants to be able to drive it too. Unfortunately, that, the traffic here and the cost nowadays for a tkx, were the deciding factors to switch over. I probably will regret it though.

For mostly family cruising keep it a stick.

If you’re going to the track a lot then an automatic makes sense. Driving around with the family in a high-stall automatic car would suck.

The Nash was the only choice 40 years ago but since then there are far superior boxes available.

Either teach the wife to deal with the stick or buy her another automatic car.

What’s the point of having a bunch of time and cash invested in a hobby car you really won’t be happy with ?

I would have backed off on the duration to something like a 235/245 and in the 650 lift range. Would make the car more driveable. As far as the trans a well built 200r4 may last..a friend of mine uses Janis Transmission in Ohio...they have a great reputation with the Buick GN crowd and are a more dedicated shop than just a name on the transmission.
One question I have is what is your fuel system?

What is your CR going to be?

Stan

I would hope he takes advantage of the Aluminum heads and has a 10.5 to 1 compression.

DonnyD,

I have a similar build in my 1970 GTO. I'm not a racer,but I think it is a low 12 or high 11 second car. It is a 461 with the same heads you have, but my engine builder does his own porting and won't tell me the numbers it flows. It has the same EFI as you. I would listen to B-Man on the transmission. I like to stir the gears and have a Tremec T-56 Magnum in it. Rear gears are 3.73.

The cam in it is one level lower than what is in your engine. Comp Cam XR-288HR @ 110LSA and 1.65 rockers. If I'm not mistaken the cam you have is the one that Butler puts into its 600HP engines.

The car has suspension and brake upgrades I won't go into here, but to give you a look and sound you might have look at this video.
https://www.youtube.com/watch?v=GYMaDAeOO3g

By the way, I live in Connecticut and plan on moving to Sarasota as soon as the house sells. Maybe I'll see you down there.

Jim

If you check, both Tremec and GM rate trans by torque capacity. A 750 HP SBC will not be making as much torque as your 600 HP Pontiac.

Stan

After rereading the OP posts,Family cruiser, run mid 11's and the wife drive it are the goals. I think the cam choice and compression ratio is key. The present combo may not like to run at 60mph in overdrive..less duration and higher compression in the 10.75 to 11 range would help. I personally would send the cam back, and find out your compression ratio and if need be shave the heads to achieve a higher ratio. My engine in my signature drives like a pussy cat and a similar build would be perfect. You would also get 20mpg plus.

power brakes? i think you are pushing it already with 242 @ .050 ...

I thought the same thing when I had my 496 built for my '73 T/A with the same cam the OP has. @242/248 @112LSA. The car has a Wilwood brake system. 12.1 inch rotors with 6 piston calipers in the front and four piston in the back. Also has a Wilwood master cylinder and proportioning valve.

Stops on a dime.

yep. power brakes and power steering

Hopefully we meet at the bradenton track. Not too far from either of us. Im in the riverview area. Thats a very nice ride. Sounds amazing. Glad you're switchin over to being a floridian. It'll take some getting used to the weather. Sarasota is a beautiful place to live.

10.5

yes. 10.5-1. sorry for not listing that

4.25 stroke? is a 496 a 4.31 x 4.25 combo?

My pb are fine with OF in a 505, but that's a 236 @ .050 on a 112, 4.25 stroke.

its a 10.5-1 compression. Flat tops with the 87cc chambers. I may just swap out the cam, but now im kinda worried about vacuum and drivability. I guess you cant have the best of both worlds.

Manual brakes are fine if you’re worried about vacuum.

And there’s always hydroboost which a lot of guys like.

4.5 inch stroke in the 496 and stops great. Was going to go with 110LSA on the cam and was worried about vacuum. Changed to 112LSA and the brakes work great.

My GTO with the 461 has a 4.25 inch stroke with the same brakes as the '73 TA.
Only difference is the front & rear calipers are 4 piston. Also, stop on a dime. Cam is at 110LSA, 236/242 @ .050.

I have a shop here in Jacksonville, Florida and do nothing but Pontiac's. We've built over 150 Pontiac engines. I think the combination you described is pretty good all the way around. Your vacuum with that cam will be fine. I might consider a 3:73 gear instead of the 3.50 with the 200r4 though. I have used several Art Carr 200r4 transmissions for customers behind engines similar to yours. They have held up well and the only issue is that they underestimate what the stall speed will be on their convertors. Their "2600-2800" convertor is actually around 3500 behind a healthy Pontiac engine. I actually have an Art Carr BUILT 200r4 on the shelf for sale if interested. Regarding the engine. Make sure that you degree the cam in at around 108 ICL and do use the 1.65 rockers. Also, try a 1" spacer on your intake. I recently put one on my street car and it picked up a tenth in the 1/4.

467 cid with 263/242 @ .050 on 112 LSA and I have about 14.5 vacuum at 750 rpm.

Sure you can,it's not the old days! You will get a hundred different opinions on cam choice..but the simple solution is go on the Butler site and pick another that has exactly the same valve lift..I've seen a few there when I looked so it will work with your current valvespring setup..something in that 235/245 range.

I knew an older fella that had a big red station wagon one time….

Going with a Holley sniper with their in tank fuel pump.

I’ll let you know tomorrow about that 200r4. What’s your asking price on it? I appreciate all the great info. If I knew you guys existed, I would have certainly brought the engine to you.

I'm building an engine for a customer in Tampa right now. Give me a call if you'd like. 904/868-9207

As Bman mentioned earlier. A little more cam put my heavy stock 70 GTO in the lower 7s 1/8 mile ( high 10s? Quarter) with a 254/[email protected]. .582 lift sr with 1.5 HS. 315 Eheads, 10.8 cr 470. Continental 10" converter. 370 Ford 9".

I think a mid to low 11 sec 1/4 is doable. My 70 gto had a 455,,#62 heads ported to to 250 cfm,t2 intake,800 dp holley,ra4 sized cam with rhoads,3.73 rear with 10" jim hand converter,thm400.. Full exhaust. Rest of the car was all stock. .not stripped..PS,PDB. 3950+ lb with me in it Ran 11.7 at 115mph (7.4 1/8th mile) and actually was a mild combo. Definitely not as much as your engine.