SBC Alu Heads Designed for Torque

[aotte1]

Are their Alu. Heads that are designed for low RPM torque, on a SBC (350, 383, or 400)
Known a lot of the Alu heads are designed for max performance at higher RPM.

Thanks,
Les

[Warrens69GMC]

edelbrock Etec170's
http://www.edelbrock.com/automotive/...c-170-sb.shtml

[Marv D]

Port velocity is what supports low RPM torque over high RPM power. Biggest key in that is the port that keeps the intake charge moving quickly to the chamber keeps the fuel 'mist' in suspension. That was the idea in the late 90's GM 'swirl port' head. (keep turbulence's in the intake charge so the fuel can't drop out of suspension at low speeds) Althought not a 'performance' head by ANY term,, they did make good torque from idle to around 3800 (which is 99.9% of the truck motor operates)

That's why a 'Large by HUGE' intake runner is not as good at low RPM power,,, as it is at flowing massive amounts of air to support high RPM. It's a compromise of keeping the A/F mixture in check at high speed with a small runner,, vs. a large runner that will flow more A/F when there is demand at high RPM.

The 170cc vortec is a good head for low RPM torque (in stock form or the E-tec Edelbrock), no denying that. BUT so is the AFR 180cc standard 23° / standard SBC intake configuraton that ROCKS in a heavy truck.There are a number of decent small runner aluminum heads out there right now, just don't fall in to the evilbay No-name import JUNK heads. Those appeal to the unsuspecting. Do your homework on ANY off-brand or house brand aluminum head. There are good and bad,,, and WORSE!

BUT with the head, consider a valve train upgrade to a nice hydraulic roller that will take advantage of the low lift flow. You can not achieve valve action with a flat tappet like can be had with a roller. It's a significant cost to upgrade but the risk of loosing a cam to poor oils or cam breakin disappear!!. You start it up and let it idle. WAY better on the new engine (and the nerves)

I have a set of 170 E-tecs on a 327 in my El Camino with Holley MPFI and a custom hydraulic roller,,, and had a set of iron RHS vortecs on a 383 in my 94 4x4 also a hydraulic roller motor. The ONE thing I can tell you after many miles on both,, I've built my LAST Vortec head motor. Not worth the BS of intake and rockers and rocker covers and re-routing the plug wires / looms. Today there is JUST AS GOOD out there in standard SBC form as the vortec

[snj8198]

good info as always Marv

[mattfranklin]

Originally Posted by Marv D

Port velocity is what supports low RPM torque over high RPM power. Biggest key in that is the port that keeps the intake charge moving quickly to the chamber keeps the fuel 'mist' in suspension. That was the idea in the late 90's GM 'swirl port' head. (keep turbulence's in the intake charge so the fuel can't drop out of suspension at low speeds) Althought not a 'performance' head by ANY term,, they did make good torque from idle to around 3800 (which is 99.9% of the truck motor operates)

That's why a 'Large by HUGE' intake runner is not as good at low RPM power,,, as it is at flowing massive amounts of air to support high RPM. It's a compromise of keeping the A/F mixture in check at high speed with a small runner,, vs. a large runner that will flow more A/F when there is demand at high RPM.

The 170cc vortec is a good head for low RPM torque (in stock form or the E-tec Edelbrock), no denying that. BUT so is the AFR 180cc standard 23° / standard SBC intake configuraton that ROCKS in a heavy truck.There are a number of decent small runner aluminum heads out there right now, just don't fall in to the evilbay No-name import JUNK heads. Those appeal to the unsuspecting. Do your homework on ANY off-brand or house brand aluminum head. There are good and bad,,, and WORSE!

BUT with the head, consider a valve train upgrade to a nice hydraulic roller that will take advantage of the low lift flow. You can not achieve valve action with a flat tappet like can be had with a roller. It's a significant cost to upgrade but the risk of loosing a cam to poor oils or cam breakin disappear!!. You start it up and let it idle. WAY better on the new engine (and the nerves)

I have a set of 170 E-tecs on a 327 in my El Camino with Holley MPFI and a custom hydraulic roller,,, and had a set of iron RHS vortecs on a 383 in my 94 4x4 also a hydraulic roller motor. The ONE thing I can tell you after many miles on both,, I've built my LAST Vortec head motor. Not worth the BS of intake and rockers and rocker covers and re-routing the plug wires / looms. Today there is JUST AS GOOD out there in standard SBC form as the vortec

Thanks for sharing your experiences. It helps a lot. The temptation toward the VORTEC side is real. ;-)

[aotte1]

Marvin,

Thanks for your information. A little follow up on the " AFR 180cc standard 23° / standard SBC intake configuraton ". Considering this head, if I read your description correct, this is a strong lower RPM torque head, one of the better ones. Do you have specific part number for the AFR 180. Do you suggest the smaller 1.94 valve too.

Definitely will do the hydraulic roller, question is finding one more designed for torque vs RPM HP. The smaller COMP 4x4 rollers are still pretty big cams, at least the ones I have seen.

thanks,
Les

[snj8198]

Consider a custom cut billet cam Les. If you dont find an off the shelf grind, it's well worth cutting one specific for your heads and build needs. I got mine from Chris Straub Tech.

[aotte1]

Steve,
Thanks for cam suggestion, will check them out. The engine is for a 65' C10 short bed, turbo 400. Trying to decide on cubic inches for SB. Considering a 350, 383, and some version of a 400.

Les

[toolboxchev]

Originally Posted by aotte1

Marvin,

Thanks for your information. A little follow up on the " AFR 180cc standard 23° / standard SBC intake configuraton ". Considering this head, if I read your description correct, this is a strong lower RPM torque head, one of the better ones. Do you have specific part number for the AFR 180. Do you suggest the smaller 1.94 valve too.

Definitely will do the hydraulic roller, question is finding one more designed for torque vs RPM HP. The smaller COMP 4x4 rollers are still pretty big cams, at least the ones I have seen.

thanks,
Les

Not a bad thing, yet I found myself on YouBoob earlier watching all the videos on Comp Cams with engine sounds. After about 4 of those videos I was saying Sounds Great, now lets see if it will lay down some power. NOT happening.

The masses will appeal to this, yet I find myself wanting more than just a sound. Comp will stand behind you, they did for me and I am still running 70 k on hyd flat tappets.

[Warrens69GMC]

camshaft-14097395
https://www.summitracing.com/parts/nal-14097395

[geezer#99]

Originally Posted by toolboxchev

Not a bad thing, yet I found myself on YouBoob earlier watching all the videos on Comp Cams with engine sounds. After about 4 of those videos I was saying Sounds Great, now lets see if it will lay down some power. NOT happening.

The masses will appeal to this, yet I find myself wanting more than just a sound. Comp will stand behind you, they did for me and I am still running 70 k on hyd flat tappets.

You shoulda listened to vids with Chris Straub cams, then you'd hear power.

[Marv D]

http://www.airflowresearch.com/180cc...cylinder-head/

Depending on your deck height / piston configuration and resulting compression,,, I'd HIGHLY suggest you stick with the 0911 (65cc) or 0916 as (75cc) for the straight plug version. The angle plug does offer some advantage, BUT at this level it's a onsey - twosey thing and your sanity in header choice and plug wire clearance is HUGE compared to the small advantage of the angle plug.

For cam,, Cant really make any suggestion without knowing exactly what you have for compression (deck clearance, piston, bore, stroke, gasket), intake, carb / injection, and the complete drive train from converter to tire diameter, vehicle weight, exhaust configuration,, and a ton of things beyond the scope here.
Like SNJ is saying,, the expertise of guys like Chris Straub is well worth the $ spent. They are not just offering you free phone advice and selling you a shelf stock cam that seems to fit what info you can offer,,,,, they are working through the engine pulses at the average RPM your working YOUR combination of parts,, and picking a lobe that fits the need.

In all honesty most of the guys that 'design' a cam are doing their magic, then picking lobe profiles from the master lists of their favorite grinder, and ordering the core with lobe "A" for intake lobe "B" exhaust on a xxx° LSA and having the desired distributor gear pressed on.

If you look youcan usually find your custom cam lobe in the master list of one of these companys like Bullet. Here's their hydraulic roller lobe profile master.
http://www.bulletcams.com/Masters/HRlobes.htm

And that is a reasonable option too. The guys at Bullet are EXTREMELY sharp and will work with you to pick a combination of lobe profiles to compliment you ruse,,, or come up with a shelf stock cam that is pretty close.

You can get hydraulic roller lobes as mild at 180 and 190 which is the same as the STOCk GM TBI cams. The trade off in short duration is you sacrifice LIFT,,, and the AFR heads LOVE lift. Even with a roller you can only get so much lift , given a particular duration, os a SBC core befor eyou have to run such spring pressures it puts durability (and the hydraulics) at risk.

Just what little we know,, I'd really suspect something with a 195-200° @ 0.050" and a .30 - .35 lobe, with a set of 1.6 rockers to get lift up to .55 if possible is going to be where most will suggest if you set compression at no more than 9.2:1, and use the AFR head on carburated a 355 intended for WORK and towing and unlikely more than 4500RPM

BUT, that's just a guess. I'm not a cam designer and there are way too many unknowns to go deeper.

[aotte1]

Marvin,

Thanks for all the info, big help. Still deciding to go with a 327 small journal block, with 350 crank offset ground; or a SBC 400 block. Decision is how original I want engine to look???
A 400 with new TBI fuel injection sounds nice too! Trans will be a turbo 400, likely with a switch pitch converter set up.

Thanks,
Les

[tjsblazer]

Good discussion here.
Since I've seen custom cam grinds mentioned I would also consider Mike Jones. Between myself and a friend of mine we have 3 of his camshafts. Been happy with them and also Mike's availability for personal service. Well worth a small upcharge over a catalogue grind through the more common providers.

[Marv D]

Yeah there are a lot of darn sharp guys out there. I used to use Jay Allen (Caminnovations) before his mouth got him in trouble. I wasn't paying for his personality so his frustration he had over people that wanted him to work out a can design,, and then took his work and bought a shelf stock Comp, Lunati, Crower etc didn't bother me. You can't get 'stuff' like the roller in my Camino off the shelf...

220 / 226 @ 0.050, .568 / .566 lift with 1.5 rockers on a 113.5 LSA. That's something like I'd like to see on this towing motor with a set of AFR 180's

People call and expect a custom cam designer to spew out numbers for them,, it don't work that way. They put a LOT of time into coming up with what is 'right' for your particular pile of parts. Thats how they make their living.

I guess all that's saying is,,, Expecting a custom cam designer to come up with a suggestion for a cam is just asking them to work for free. YOU wouldn't do it,, don't ask them to. The way that works is you find one you trust, you PAY HIM and then he does his work.

[aotte1]

Marvin,

Thanks for all your information.

Do you think the suggested cam, will work good with stock converter in turbo 400. Possibly will put the Buick switch-pitch converter in the 66' truck turbo 400. That will give more stall at idle and initial acceleration. Run bullit cams that they suggest in 1970 GS, C/SA, didn't he used to be at Cam Dynamics?

Jeff, thanks too.

Thanks,
Les

[aotte1]

Marvin,

Thanks for all your information.

Do you think the suggested cam, will work good with stock converter in turbo 400. Possibly will put the Buick switch-pitch converter in the 66' truck turbo 400. That will give more stall at idle and initial acceleration.

Thanks,
Les

[Marv D]

Without a final decision on cubic inches, compression, heads, exhaust, induction and the choice made for everything from tire gear, trans vehicle weight, expected operating RPM band, You crally can't make much plans on what cam to use.

Up above you were still on the fence about the block , crank and all so really hate to push you too much towards ny cam. hat's why the custom cam guys are recomended.

For shelf stock,, 8.5:1 compression and a 350 a cam with 190-205 @ 0.050 may be good for a heavy truck with 42" tires and no gear change ,,, but be a stupid choice for something 'sportier' with a loose converter and OR more cubic inches.

Cubic inches gobble up cam duration like a fat cousin at Thanksgiving. a cam like the ever popular Comp 268H in a stock 70's emission 350 with low compression and 'car' tires / gears might be IDEAL in a 355 or 383 ,, but WAY TOO MUCH for a 6500 pound 4x4 with 3.43 gears and 33 or 40" tires.

A custom cam designer will ask more questions than you can possible answer. Then you start the work if finalizing the combination. Only then can the 'right' cam be chosen / selected. THEN you will know your getting a cam designed for YOUR particular bucket of bolts.