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Here's the rabbit hole I'm heading down...
As an example.
Which of these will stand up to minutes of WOT? Or at the very least minutes between peak torque and peak HP?
I know which would survive but it's how far can you go for what level of performance? From my experiences with the XR profile, I think it would stand up. Not sure of the aggressive Jones one though. And the Magnum (high lift) really takes off after 0.200".
I've got a couple of emails out asking those questions and am hopeful for a reply.
From Crower:220 High RPM Series
The 220 series was designed for Hot Street, Oval Track or Drag racing. The 220 series is similar to the 290 series, but is designed to run with only the highest of rocker ratios. When using the highest of rocker ratios, this series incorporates smooth lift rates for increased durability in high RPM ranges while utilizing moderate spring pressure.
Building for 90 miles of Nevada highway.
Although limited by maximum top speed as the license vs experience requires, it'll be flat out for miles at some point.
The Silver State Challenge is probably beyond the scope of my eligibility (and pocketbook) but the somewhat closer Sandhills Open Road event may be a more reasonable target.
Touring (Speed classes: 95, 100, 105, 110 mph)
Stock street cars with regular 3-point seatbelts may be run in this class. A handheld fire extinguisher must be fitted, while gloves and Snell approved motorsports helmets must be worn by drivers and navigators. First-time drivers must run in this class unless they have appropriate motorsports experience. At no time may the car exceed the Tech Speed of 124 mph.
Grand Touring (Speed classes: 115, 120, 125 mph)
In addition to a handheld fire extinguisher, gloves and Snell helmets, the car must be fitted with 5-point or 6-point harnesses for the driver and navigator (if present). Open cars must have a rollbar fitted. At no time may the car exceed the Tech Speed of 140 mph.
Grand Sport (Speed classes: 130, 135, 140, 145, 150 mph)
In addition to the above equipment, all cars must be fitted with a rollbar or equivalent roll-over protection. Drivers and navigators must wear fireproof racing suits. At no time may the car exceed the Tech Speed of 168 mph (270 km/h) (the speed rating of ZR tires).
The Grand Sport class looks like the ultimate target and a reasonable one too although a lot of car building for that one. Sort of like going legit low 11's.. But I'd be starting in the entry level class and it still has a maximum top speed of 124 MPH. If I don't get into overdrive, that's nearly 6000 RPM for my gearing and tire. Hence the need for reliable parts. And incidentally, 124 would be a pretty decent 1/4 mile speed.
Last edited by skinny z; Aug 16, 2021 at 07:58 PM.
From Crower:220 High RPM Series
The 220 series was designed for Hot Street, Oval Track or Drag racing. The 220 series is similar to the 290 series, but is designed to run with only the highest of rocker ratios. When using the highest of rocker ratios, this series incorporates smooth lift rates for increased durability in high RPM ranges while utilizing moderate spring pressure.
(MFTC) Mechanical Flat Tappet Camshaft
OOPS. I thought it said Mechanical ROLLER.
This brings to mind all of the manufacturers I haven't though t about.
Thanks for the reminder. I'll be checking Crower too.
I'd say the most public benchmark is Vizard's Vortec 350. It made 447 HP with 224 @ .050" on a 108 LSA. They never gave the seat to seat specs (it's tagged as a custom grind from COMP) so it could be anywhere.
You've more cubes. Less cam. Better heads (IIRC). I'd say your odds are pretty good. Remember that 447 was optimized on the dyno. There's a lot to be said for that.
If the above is an XR lobe, that would be the equivalent to the intake on their XR276HR. That puts the overlap in at 60°.
Made healthy enough idle vacuum too. Predicted to be 15"Hg. That's on a 350 remember.
Last edited by skinny z; Aug 16, 2021 at 09:32 PM.
More like increasing the intake duration a bit, reducing the exhaust duration so its equal, and adjusting the LSA to keep roughly the same bit of overlap I have right now.
I'd say the decision making path there is how you think the intake and exhaust stack up. Is the exhaust side efficient? Can you afford to take some away? As far as the intake it seems you can never get it open far enough, fast enough or long enough.
Is that LT1 of yours packing some compression?
If the above is an XR lobe, that would be the equivalent to the intake on their XR276HR. That puts the overlap in at 60°.
Made healthy enough idle vacuum too. Predicted to be 15"Hg. That's on a 350 remember.
He's getting about 13" inHg in gear at 575 rpm... and that's on a 383.
I think he needs a better tune.
I'll qualify that by saying I haven't got all the build specs. I've asked. Seems the vacuum is low to me too although that's only 575 RPM.
Last edited by skinny z; Aug 16, 2021 at 10:01 PM.
Idk why a motor needs to idle at 600 or less rpm. I never had one that idled less than 900 lol
for open road race id be worried about hyd lifters and oil foaming. I suppose it can be done tho, but i would lean toward a more stable lobe for sure. Big thing is the tuning, over time heat in the chamber builds up so you want to make sure you can adjust for that. Usually fuel curve goes richer in time and timing may decrease some. Or put better fuel in it. Cut it with ethanol or put 110 in it
Like a lot of folks, often the total build comes along in smaller steps.
First IROC I modified started with the engine. That was in front of a huge converter of unknown manufacture. Then came the transmission mods. Then another converter. Rear gears.
And repeat as things got broken.
...
for open road race id be worried about hyd lifters and oil foaming. I suppose it can be done tho, but i would lean toward a more stable lobe for sure. Big thing is the tuning, over time heat in the chamber builds up so you want to make sure you can adjust for that. Usually fuel curve goes richer in time and timing may decrease some. Or put better fuel in it. Cut it with ethanol or put 110 in it
All valid points for sure.
Though it makes me wonder how a bone stock 10 year old Corvette competes. I get the computer controlled fueling and timing as an advantage but those bottom ends, despite being somewhat more robust than the old Gen 1 SBC are still OEM in design. Hydraulics and all.
It is certainly doable. There are marine engines out there that are hyd roller. Just gotta make sure everything is a good match for the use, geometry and clearances are set right,etc. oil cooler maybe warranted here. Maybe thicker grade to handle the heat better. Not sure
as far as mods in stages I totally understand. But its one of those things, if engine is out the converter is just laying there lol budget another 500-700$ or so and get a mid grade converter. I think thats one of the best first mods even for a stock car
Here's the rabbit hole I'm heading down...
As an example.
Which of these will stand up to minutes of WOT? Or at the very least minutes between peak torque and peak HP?
I know which would survive but it's how far can you go for what level of performance? From my experiences with the XR profile, I think it would stand up. Not sure of the aggressive Jones one though. And the Magnum (high lift) really takes off after 0.200".
I've got a couple of emails out asking those questions and am hopeful for a reply.
Magnum High Lift, Rhoads V-Max and 1.7 rocker combination is what I have in my 383. Idle is pretty darn smooth and it pulls good vacuum. ~19 in/hg @ 750 rpm for the 218/228 @ 0.050 on a 108 LSA and 106 ICL. Just stabbed my 383 back in but I already know its going to be a strong runner. I chased the UP 4014 Big Boy all over this weekend for videos of it or I would already have it running and driving again. 750 is ny target rpm because that is what feels normal with my 2,800 rpm stall converter. It has a slight forward creep when you let off the brakes and does not pull against them trying to stop and it also puts my a/c compressor turning stock like rpm at idle with the 25% underdrive. In park/neutral I idle 850.
I was waiting to about the end of the year or so due to some other expenses that came up earlier, but my wife and I said that not much is likely to change between now and the end of the year, so I may as well just order it now. Plus we were saying it'd suck if the price started going up.
Any rate estimated ship date is 10/25, so we'll see how it goes.
I was waiting to about the end of the year or so due to some other expenses that came up earlier, but my wife and I said that not much is likely to change between now and the end of the year, so I may as well just order it now. Plus we were saying it'd suck if the price started going up.
Any rate estimated ship date is 10/25, so we'll see how it goes.
Going off memory here, I want to say the Marine 6.3, HT383 and ZZ383 all used the same shortblock.
It is certainly doable. There are marine engines out there that are hyd roller. Just gotta make sure everything is a good match for the use, geometry and clearances are set right,etc. oil cooler maybe warranted here. Maybe thicker grade to handle the heat better. Not sure
as far as mods in stages I totally understand. But its one of those things, if engine is out the converter is just laying there lol budget another 500-700$ or so and get a mid grade converter. I think thats one of the best first mods even for a stock car
I built my 383 to be able to handle a sustained 5,500+ RPM at full load, for miles if I need it to. I have run it a few times to 6,500-6,700. Just because it wrapped so quickly it just happened. With the smaller cam it should make peak torque around 3,600 and peak HP about 5,500. With the larger Bootlegger cam it made peak around 6,400 rpm. It towed great but the cam was a little aggressive for the application. Power really came on at 2,500+. Even with the big lunati cam the Express pulled my 26', 6,000 lbs travel trailer noticeably stronger than my mom's 2019 Titan S crew cab does and it does an excellent job towing it! Titan makes close to 400 hp and 400 tq and has an excellent 7spd automatic. That being said the Express van however does not get the 23-24 mpg the Titan does unloaded with the cruise set at 75 mph.
I built my 383 to be able to handle a sustained 5,500+ RPM at full load, for miles if I need it to. .
What are the internals if you don't mind my asking?
Crank, rods and pistons are what I've bee shopping for. Then with the demands as you're describing (sustained WOT or nearly so for miles as in the Silver State Challenge), my engine builder stepped up the quality of the bearings as well. And a pile of machine work to get things square.
My build sheet:
Last edited by skinny z; Aug 22, 2021 at 04:27 PM.
Reason: grammar and clarification
What are the internals if you don't mind my asking?
Crank, rods and pistons are what I've bee shopping for. Then with the demands as you're describing (sustained WOT or nearly so for miles as in the Silver State Challenge), my engine builder stepped up the quality of the bearings as well. And a pile of machine work to get things square.
My build sheet:
Very similar to yours. Sub an 880 block with 4 bolt caps, 1-piece rear seal crank with external balance for the flexplate like all 1-piece rear seal setups, Weisco forged pistons with 6cc worth of dual reliefs, and procomp 6" H-beams. Pistons were 0.013" under deck.
Yes. Very similar.
I've gone out of my way for an internal balance. The idea of a weighted balancer didn't fit well with the endurance aspect. The notion of having the crankshaft break at the front journal wasn't very appealing. As such, my builder (or potential builder I should say) has recommended a lightweight low expansion forging for a piston. I can't say I care much for a 16cc dish but with heads that have 64cc chambers, it was a necessary compromise.
Same with the cam lobe profile. Plenty of options in the 284-288 advertised territory. The decision now is to decide whether I want somewhat aggressive or somewhat gentle on the lifter acceleration. There's quite a difference between a 284 lobe that's 224 @ .050" and one that's 236.
Here's hoping...
I would maybe look at the more aggressive lobe families from comp. can get lift and added .050” duration and .200” duration with similar or even smaller seat to seat timing. Best of both worlds. More area under the curve and since you arent turning alot of rpm, wont need a ton of valvespring to control it
xfi or similar lobe. Maybe even high lift magnum or comp xe high lift. Or some of the newer q stuff. I havent looked at the catalog in a while
3192 lobe on a 110, very close to Mike's ehr 71360 lobe. To the op, if vacuum for brakes is the only concern a vacuum pump isn't that big a deal, and not expensive. Hate to see you be down 15-25 hp for that one factor. With the 383 you will have a lot more tq, and not just at peak. This is one instance where a custom cam really is worth the extra 50-75 bucks.
The 3192 is about the middle of the road by intensity standards. It would last forever (as mine did) given the application. Same intake lobe as in the XR276HR. 276 adv./224 @ .050. That was 59 degrees of overlap and plenty of vacuum on a 110 LSA. Should be pretty good even on a 108 (104 ICL) in a 383. I wouldn't think anything other than the OEM power brakes would be needed.
FTR, I was running 71 degrees of overlap in a 355 and still had fully functional power brakes. Vacuum at idle on a worn out short block was still 10-11" if I upped the idle speed a little . Something like 850 RPM and plenty of initial advance.
Jones EHR 71360 is quicker still with 276/230 and gets to .576" lift with a 1.6 rocker. Not sure how that would shake out in an every day driver. That's more like Comps XFI lobes. While quick, I found them noisy and harder on parts. Particularly if your valve train geometry isn't spot on. Which I learned way back then that mine wasn't.
That said, shorter seat to seat duration will give you better vacuum given the same .050" specs.
So far it idles at 14-15 inHg in gear at 650 rpm. The 2500 rpm Hughes converter probably contributes to that high vacuum as well since it reduces the load on the engine at idle. But so far I'm liking the smooth idle.
Couple of minor things to iron out like a leaking fuel pressure regulator. Probably next weekend. But after that, should be able to get this thing on the road.
So far it idles at 14-15 inHg in gear at 650 rpm. The 2500 rpm Hughes converter probably contributes to that high vacuum as well since it reduces the load on the engine at idle. But so far I'm liking the smooth idle.
Couple of minor things to iron out like a leaking fuel pressure regulator. Probably next weekend. But after that, should be able to get this thing on the road.
Well done on the up and running.
Do you have a shortcut to your other engine details?
Are these the street version or the comp version of the old 180 cc head?
I've got a pretty good data base going and I'd like to check these out.
383 yep.
The AFR heads are about 20 years old. I bought them for the ZZ4 when I did that engine back around 1999. Not sure what design updates AFR has done since that time.
Two versions were available back then. Street and Comp.
I was just punching through the numbers on DynoSim looking for where your combination would land it's peak HP RPM and torque.
I've a similar small head for a 383 I had been thinking about building. It makes for a fairly competent package without a lot of RPM induced stress.
Sort of like this.
Street AFR 180 cc head. Data from Stan Weiss.
Small tube header (1 5/8). Open exhaust.
500 lb-ft at 2000 RPM.
Last edited by skinny z; Jan 24, 2022 at 04:37 PM.
413 lb-ft at 1000 rpm? Hmmm... I guess I'm a little skeptical....?
You have to wind a ZZ4 up to nearly 4000 rpm just to get 400 ft-lb. A little better heads and a little better cam on a 383 makes that much torque ~3000 rpm sooner?
413 lb-ft at 1000 rpm? Hmmm... I guess I'm a little skeptical....?
You have to wind a ZZ4 up to nearly 4000 rpm just to get 400 ft-lb. A little better heads and a little better cam on a 383 makes that much torque ~3000 rpm sooner?
I'm not saying it's accurate in terms of output, I'm demonstrating where those peak HP and torque RPMs are at. It's low RPM torque monster and will pull a freight train.
You have small heads that will be short of filling a 383 too far into the RPM range. I'd say with cam that was spec'd to require the ports best output, you could top out near 6000 k. More like 5500 is what I found when simulating my project.
But the cam is small. Really small for a 383 to rev. And you're probably not taking full advantage of the heads you have. Which are pretty good really. (I'll buy them if you're selling...)
Here's the same combination with COMPs XR288HR. (I'm not making a recommendation I'm just illustrating how the RPMs shift.)
Torque is down down low, it's even around 3000-3500 and HP is up about 25 HP at peak and another 500 RPM higher. Same as the torque peaks.
You're using way more of the head here.
Now keep in mind the induction and the rest of the supporting are going to make all the difference. It hasn't really been addressed in the DynoSim. Your 9.7:1 takes a little of the torque production away too. But it keeps your DCR in check with the short cam.
Do you know what your installed intake centreline is?
My plans to build that 383 with my RHS heads, which have very similar flow and measurements to yours, always pointed towards a cam larger than your Crower. Peak HP RPM, if you were going for a big number would be maxed about 6000. Compression closer to 10-10.5:1
But I'm going to say you'll be able to boil the tires off.
I'm not saying it's accurate in terms of output, I'm demonstrating where those peak HP and torque RPMs are at. It's low RPM torque monster and will pull a freight train.
What are the ZZ4 cam specs?
and you have it as a tuned port on the dynosim, those powerbands won't be there.
I used a std tunnel ram to be comparable to a hsr. A single plane or a max dual plane will be closer to a miniram. It's been a minute since I last fiddled with the program to remember whats all there
Substituting the tuned port injection for a max flow dual plane as I have have, moves the power bands significantly.
Not a lot of option on this older software on the EFI side.
1000 RPM the scale with peak HP RPM now at 5500 from the tpi 4500. Looks like the program has tuned port as the OEM long runner version. Makes sense.
The RPM representation looks to be relevant. Interestingly a small tunnel ram produces similar RPM output to the carbed intake (kind of like a miniram isn't it?).
Anyway, the point of all of this was to have a look at some results and build it backwards. I'd been working out the details of a 383 (now to be a 357) and was curious to see someone else's progress.
Any plans to dyno this ULTM8Z? As mentioned, not debating output but knowing RPM peaks would be interesting.
