Stroker engine build ideas

[Llamaback]

Hi all, I am looking for some feedback on my potential engine build/combination for my 1970 Super Bee. I am wanting to build the car to be old school, simple, reliable, and a very very good street car. The rear gear is a 2.76 ratio 8 ¾ and will get a sure grip. The trans is an A833 with what I think is the standard gearset (1st 2.66. 2nd 1.91, 3rd 1.39, 4th 1.0). I want to be able to drive this car a lot and cruise on the highway around 70mph. I really would like to be able to cruise it to drag n drive events and be able to run mid 13s quarter mile times if possible. I am thinking that involves staying in 3rd gear and running up to 5400 rpm. This build is inspired by a 1970 Monte Carlo that was running in the 12s with a 2.56 rear gear ratio and a stroker BBC. Here is what I am thinking for my engine build so far:

440 -->512 stroker (already at the machine shop and have the 440 source kit on the way)

9.5:1 compression with edelbrock performer RPM heads 88 cc chambers. I want to be able to run mid grade gas if needed. It will be driven most at 4500 ft elevation

Edelbrock performer intake manifold, 800 cfm thermoquad or quadrajet. The performer intake is needed to run the spread bore carb.

Stock rocker arms

Howards 720141-12 cam hyd. flat tappet 225/235 duration at .050 and .490/.488 lift, 112 LSA on 108 intake centerline.

Is this too much cam for stock rockers to run reliably?

Other cam ideas?

I think around 580ftlbs torque and 450 hp could be the ballpark numbers.

TTI 1 7/8 long tube headers, full exhaust system

I realize this combo seems wasteful with the stroker bottom end but I really want tons of torque. I know I could go roller cam but doubt I will spend a lot of time at the higher rpms and would like to save some money. Getting good mpg while cruising at 70 would be a nice plus as well. My goal is to have a very nice driving street car but still be able to beat some of those guys that are way over-cammed, and just don't have a well tuned/sorted combination. Thanks!

 

[rickseeman]

I think you will have more than 500 hp

 

[rickseeman]

I don't consider stock rocker arms to be rocker arms. I consider them to be a stamped piece of steel. I would use the stainless steel 440 Source rockers. They look nice for $599.

 

[Llamaback]

I don't consider stock rocker arms to be rocker arms. I consider them to be a stamped piece of steel. I would use the stainless steel 440 Source rockers. They look nice for $599.

Yes those do look like they could be a big improvement. I could also run more lift if I chose those. Thanks

 

[WS23U1]

How many miles a year are you going to drive it.

 

[496 polara]

The combo looks good for the 2.76 gears. Changes I would consider;

Hyd roller cam with similar specs instead of flat tappet. Maybe have one custom ground for your requirements(Dwayne Porter comes to mind-he just did one for my 505).

Hydraulic Roller Camshaft; 1959 - 1980 Chrysler 383-440 2000 to 6200 Howards Cams 720555-12 | Howards Cams

Any porting to the heads will be beneficial as the intake. Why the 88cc open chamber? 84cc closed less detonation prone ?

Better rockers (Harlan Sharp aluminum ones they build for Mancini racing)

Depending on tire height you may consider a 2.94 sure grip

 

[hunt2elk]

Another decent rocker setup that isn't terribly priced are the Mancini aluminum made by Harland Sharpe. They don't have needle bearings like the more expense HS's. I also think your power estimate is on the light side. I would guess a solid 550 hp and ft.lbs.

 

[Llamaback]

How many miles a year are you going to drive

How many miles a year are you going to drive it.

Hopefully 3000 to 4000

 

[RemCharger]

The heads should flow .600 and the springs good for .600 , but a .490 cam? Leaving good power on the table. And I don't mean rowdy large duration power.

 

[Runcharger]

Have you thought about your clutch at all? 2.76 is gonna be a real challenge for clutch life probably even more so with big torque.

 

[PRHeads]

505, 9.8cr, prepped and bowl blended rpm heads, original Torker/Holley 850vs, 1-7/8x3 headers, 232/237-112, .483/.483 HFT cam, Mancini/HS rockers.
615tq/505hp w/o carb spacer.

Bigger manifold and cam would have easily pushed the hp numbers higher.

With 2” super sucker spacer:

My prediction prior to testing was 600tq/500hp

Edelbrock performer intake manifold, 800 cfm thermoquad or quadrajet.

The std Performer will def be a power killer.

 

[Llamaback]

The combo looks good for the 2.76 gears. Changes I would consider;

Hyd roller cam with similar specs instead of flat tappet. Maybe have one custom ground for your requirements(Dwayne Porter comes to mind-he just did one for my 505).

Hydraulic Roller Camshaft; 1959 - 1980 Chrysler 383-440 2000 to 6200 Howards Cams 720555-12 | Howards Cams

Any porting to the heads will be beneficial as the intake. Why the 88cc open chamber? 84cc closed less detonation prone ?

Better rockers (Harlan Sharp aluminum ones they build for Mancini racing)

Depending on tire height you may consider a 2.94 sure grip

Thanks! I think I am already convinced to not go with the stock rockers now. How much was your custom ground cam? I think there is a typo out there about the 84cc edelbrock performer head. As far as I know they come in 75cc or 88cc and are all closed chamber.

 

[Llamaback]

Have you thought about your clutch at all? 2.76 is gonna be a real challenge for clutch life probably even more so with big torque.

This is a good point, and something that does worry me about it. I was planning on going with a diaphragm clutch , most likely centerforce dual friction, but will go with whatever Brewers recommends. This car is a 4 speed conversion

 

[BSB67]

The standard Performer will be a huge bottleneck holding your combo back more than anything else. Still might get to your goal with it. Mill the divider out and add a spacer.

Consider 10.5:1 CR if you are going to be at 4500’. That should not be a problem at all with pump gas.

Cam is about right for what you’re looking to do.

 

[496 polara]

Talk to the gentleman in post #11. He spec'd my cam and provided the cam and lifters for my build.

 

[PurpleBeeper]

I have nearly an identical setup right now. The Centerforce dual friction clutch works fine with 2.76 gears, but it definitely takes a "touch" to pull away smoothly in 1st gear. Your rocker arms are right on the edge. I've run larger cams with stock rockers. Adjustable rocker arms/push rods are better, but stock style rockers don't need to be adjusted. It's up to you. I would advise against a larger cam with 2.76 gears or you may struggle to get the car moving in 1st gear, up a hill. I think 13's may be tough with 2.76's, but a piece of cake with 3.91/4/10 gears. You can swap gears in a few hours after you do it once or twice. Easy peasy

 

[Runner 68]

400 low deck stroked to 500. Bomb proof.

 

[Llamaback]

I have nearly an identical setup right now. The Centerforce dual friction clutch works fine with 2.76 gears, but it definitely takes a "touch" to pull away smoothly in 1st gear. Your rocker arms are right on the edge. I've run larger cams with stock rockers. Adjustable rocker arms/push rods are better, but stock style rockers don't need to be adjusted. It's up to you. I would advise against a larger cam with 2.76 gears or you may struggle to get the car moving in 1st gear, up a hill. I think 13's may be tough with 2.76's, but a piece of cake with 3.91/4/10 gears. You can swap gears in a few hours after you do it once or twice. Easy peasy

Good information, thank you. Do you mind giving me a run down of your setup?

 

[Geoff 2]

Use the RPM intake. The Performer will limit power with 500+ cubes. The RPM has the dual bolt pattern for carbs so that the TQ [ the best ] will bolt on. You may find, good chance, that the t/bore openings can be opened up to run the TQ. It should seal ok, if not run a spacer/adapter. With more cubes, engine becomes undervalved, needs a cam with tighter LSA.
[ See the 128 rule ] Unfortunately, not many shelf grinds.......
The tall gearing requires careful choice with the cam. I would use the Isky 280 Mega cam, which is a hyd flat tappet.

 

[icetech]

I run the Mancini rockers in my 318, i run a bit more cam than you are planning in that 440 and haven't had any issues... when you order the rockers also order a shim kit with various sizes, i spent a hour or so pulling/installing the rockers to get the side clearances right (i believe it was .012-.015).. put down the middle stand off first then work out to each end (fastest way i found to do it)

Just posting this to help save some time when you put it together.

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P.S. don't get nuts with the cam.... a lot of guys giving advice think max power but don't have to live with the car, you do