Kubs

I personally think that cam is too small for the 210cc heads you have. If you go to AFR195s, that cam would do better but has too much exhaust duration. I would try to find something in the 236-238 range for intake and exhaust. If you dont want to change heads AND cam, I would try that cam with 1.6 rockers on the INTAKE only with the AFRs.

gbarmore

Thought I'd share this video I mentioned about the Hot Rod guys bashing in headers and the net effect. Spoiler alert...... It did nothing... and they bashed the hell outta them. Skip to 10:45 if you just want the #'s but you really have to see what they did to appreciate how bad they beat them in.


On another note, after talking with Howard's Cam's about my set-up (that is my current cam mfg), I'm going to keep my existing cam, buy the AFR 195 competition ported heads, and to your point cuisinartvette, make one change at a time and see what happens. I figure that's the only way I will be able to provide any valuable feedback to others about a simple head swap like mine, the difference that made, and learn something in the process. If I don't get what I want out of that, maybe I'll look at the converter or cam for my next upgrade.

Thx for all the input guys.

63mako

https://www.summitracing.com/parts/h...make/chevrolet

gbarmore

Thanks 63Mako, looks like it might be a good fit for my goals... Good lift #'s that would complement the flow of the AFR 195 comps, and not too tight on the LSA. Any particular reason this one jumped out at you?

63mako

It is the right fit for your combination. Compression, heads, CI, trans, converter, Rear gear, intended use, Dynamic compression, lift, LSA, duration, operating range, valve timing events are correct for your total build combination. I would order the 8019 springs on the heads.

NewbVetteGuy

Wow AFR Comp 195s, 10.8:1 compression, a 237 duration @ 0.050" cam in a 383!! What a BEAST!
This is well over 500hp, right?

I'm confused by the statement that your forged pistons can only support 6,200 RPM in a 383 -I thought a benefit of forged pistons is that they support more RPMs safely.

If your piston's recommended speed tops out @ 6,200, that cam doesn't hit peak perf until 6,300 rpm; I'm sure 100rpm won't make or break anything but I just noticed it and figured I'd mention it.


Adam

NewbVetteGuy

I just modeled the airflow from the AFR 195cc Comp heads, the Howards custom cam, and assumed a 750cfm carb and the old and slightly optimistic (especially on torque) DesktopDyno 2000 says peak HP 510HP @6,000 and peak torque 512 ft lbs @ 4,500.

I'm more confident with the HP #s than the torque #s, but you're definitely looking @ a 500hp build and a nice torquey one at that.


Adam

cv67

Maybe the "recommended" piston speed came into play
With the good parts out these days seems moot
Plenty of guys run forged way higher than that

Sent it off to Bob Jennings Dyno in North Hills Ca (818) 894-3811
Got tired of buying different kits only to find it was still flat just didnt make the power it should have. Almost sold the car over it.
In short the dist (bearings included) and curve kits were pure junk even brand new.
Felt like it picked up 100hp wasnt any curve or timing specs Id have chosen never would have guessed.
Hes getting old works from home these days uses his own parts and a sun machine. Was right the first time.
then called Straub who set me up with an AED that was tailored just for what I have made it even better money well spent

gbarmore

Greatly appreciate the help. I have two final concerns before I pull the trigger, tell me if I'm overthinking this..... The first one is piston to valve clearance with the AFR 195 comps. They have 2.08" intake valves vs. my old 2.02's. I tried to contact Probe Pistons but they appear to be out of business. So, I can't contact them to discuss my particular piston and whether or not that will work with this set-up. Perhaps they wouldn't be able to say with certainty anyway since as I understand it, the valves in any given head could be arranged slightly differently? My pistons sit flush in the hole, and with that CAM lift of .560, and duration of 237, should I be worried? Is this a trial and error process whereby I pull out the playdoh and test clearance once I get the heads on the motor and valves set-up?

I listed that RPM limit based on what my engine mfg recommended, I guess I was inclined to follow their direction on that, but they may be conservative to limit their exposure. I guess I would be more concerned with the rods letting go as neither rods nor crank are forged. This is my first performance motor and I've nothing to really compare it with so maybe overcautious?

Hey, even if a bit optimistic, I'll take it. Sounds like fun to me, and that's the whole point, right!? Thanks for sharing those specs!

gbarmore

Forgot to ask, is it recommended to install new cam bearings when installing a new cam? I only have about 6k on them. I've not pulled my cam yet so I've not done a visual inspection of it.

MotorHead

You guys are over analyzing things, Get the AFR heads and cam to match your compression which would be in the ~250 @ .050 range. That will make you over 500HP easy.

Then you can return the heads to Guangdong China for a refund

GOSFAST

The 2.080's don't work all that well on a 4.000" bore "streeter"??

Just my opinion here. That type basic combo here gets a straight 2.020"/1.600" setup. We do have 2.055's/1.600's when chasing HP on the 383" platform, these come in around 560+ HP. We go to 2.080's or 2.125's/1.600's on the 4.125" platform. These make 600 HP on pump.

Having said all that you should be fine with the "radial" clearance on the Probes. They are/were excellent pistons, just never cared for the lack of "pin-oiling"?

Thanks, Gary in N.Y.

P.S. Would also recommend 1.750" primaries on your platform. My opinion here also! About 90% of all our (street) 383" builds get dynoed with this header size!

cv67

Save the 2.08 for the bigger bores
Most "550hp" 383 dont even really break 500 dont believe all you read
Making 475-500 isnt to hard, not too pricy and easy to live with. 550+ isnt and gets expensive very fast.

Like ya read a lot take driving style gear weight and be very honest with yourself, build accordingly youll be happy. Lots of cars that make crazy dyno #s that would get their azz handed to them in a heads up race by something with far less power. Always fun to see what you can squeeze out of them though.
Fine tuning and chasssis are something lot of guys overlook or cheap out on use it to your advantage.
Have a number of members in the C4 sec that dont even make 400hp on a good day running bottom 12s/11s and sound stock or very close to it;daily drivers and smog friendly

gbarmore

Thanks Gary. When you say the 2.08's don't work well on a streeter, can you explain that? Not doubting, just trying to learn something here... Running the standard AFR 195's with 2.02's over the 195 comp's with 2.08's would save me over $400. At .550 lift the difference in flow is ~14cfm intake and 11cfm exhaust. It's about an 8% increase with the comps. Worth it?? Oh, and I do have 1 7/8" primaries so all set there.

All-out horsepower is not the goal here, but rather a really strong low-mid range power mill. stoplight to stoplight and cone to cone... Would I love to be able to say I have 500+ hp and tq on tap, of course! However, I am willing to save that moment for the day I build my 427....

GOSFAST

The valves are simply too big for your platform, I would stay with a 2.020"/1.600" on a 4.000" bore making power at or under 6000.

We pay very little attention to "flow numbers", they don't mean too much to us here. Those 2.020's can get you up to and past 550 HP on the correct platform. Recently finished a 383" (pump-gas), 570 HP/500 Torque with this size valve combo. Not a real comfortable grocery-getter though. Also not a "cheap" build.

You kind of lost me there on the pipe size?? The pipes are most likely going to cost you some power??

Thanks, Gary in N.Y.

P.S. I also don't really care all that much for AFR heads either, but again, this is just me. I can count on one hand the number of sets we use/sell in any given year. I put the Dart's in the same category! For "streeters" I'm comfortable with the RHS line, for all-out power/racing, maybe a set of All-Pro's?

63mako

My build is similar to yours. 383, 10.4 to 1, AFR Competition ported milled to 72 CC, Hooker headers, sidepipes, Maxflows. Cam is 236/242, Lift 527/547 LSA 114. Large base 837 CFM Tripower. I got 515 HP and 495 ft lbs on a stingey dyno with 1 5/8 dyno headers (only ones he had that fit). The tripower intake and small primaries cost me a lot of peak power but it is scary fast with the close ratio 6 speed and Tom's 411. Cam is set up for a 175 shot of nitrous. If I planned on no nitrous I would run the cam I recommended to you. I can run midgrade fuel no problem. The Competition ported heads come with the 8019 spring upgrade so the price difference drops $75. I think the AFR competition ported 195 is the best head you can run on a hot 383. They flow what everyone else's 210's flow with better port velocity.

Ibanez540r

All rods are forged. Your crank is not and where the RPM limit is recommended.

..In reference to your question "why" on the recommendation against 2.08 valves - valve shrouding. The theory is with smaller 4.0X" bores, the 2.08 valves are closer to the cyclinder wall and it negatively effects the flow into the cylinder/chamber. Not an issue with larger 4.1XX" bores.

gkull

My 383 has 11.2 C/R AFR 210 heads with 2.08 intakes. I've also used 2.10 intake heads on it still ran like a champ. both heads were 64 cc and i use SRP forged pistons. I have plenty of piston clearance with mid .600 lifts

I used to work on a Race car with 4.030 bore that had Dart 18 degree heads with 2.15 valves and it was powerful.

My old BBC came from the factory with notched cylinder walls to clear the 2.18 valves. Is it ideal, maybe not. Does it work, definitely yes.

99% of the side pipe header systems are not tuned pipes. They are more for looks. The primary pipes are too long. True tuned headers put some thought into primary pipe length, diameter, and collector size.


As to RPM limit. I'm a firm believer in fully ARP studded 4 bolt blocks and bigger main caps.

As to paying for the competition porting from AFR. you do understand that they are no longer 195 cc. They might become 205 cc. That is why I just went ahead and bought the 210 cc. another vendors factory porting job turned "215 cc" into 227 cc when I went to 2.10/1.625 valves from the original 2.08/1.60 marketed

gbarmore

Great info, thanks 63. I called Howards about using the 8019 springs with the Cam you recommended, and they said they were a bit stout at full open. Their real concern maybe wasn't the CAM as much as the lifter I was using, and to quote them "make sure your lifters will handle that spring pressure". I am buying new lifters, so I did some digging and even called Summit Racing and neither of us could not find specs on any MFG's lifters stating a safe or appropriate spring pressure range. I was going to go with standard Chevy performance lifters like this.. https://www.summitracing.com/parts/nal-12499225

Any reason these wouldn't work? I looked at other MFG's as well, but just saw higher costs and not necessarily 'better' lifters, at least from the descriptions. Open to suggestions there as well.

Ibanez540r, thanks for the reply, good info on the valve shrouding topic. All rods are forged?? You sure about that?

Ibanez540r

Yes, your basic stock rods are forged. Later on were PM (powdered metal). There were no cast Chevy rods.