Suppose for the sake of discussion, I know this guy who like Hemis and has always figured more is better, and too much is just right. But his buddy thinks he might be getting too old for all the maintenance, and thinks he should cut his work load, so he is considering building a low maintenance big inch hemi for street/strip, like drag and drive. Something that could be driven and raced without constantly messing with it. He already has a big bore raised cam KB block laying around, and a set of Stage V heads:

45 Degree Seats for durability
Exhaust Port with 1.90" Valve Intake Port with 2.30" Valve
Flowed at 28" without tube. Flowed at 28" Backcut intake 37.5 degrees
.100" 59 .100" 76
.200" 130 .200" 164
.300" 184 .300" 245
.400" 232 .400" 320
.500" 265 .500" 396
.550" .550"
.600" 285 .600" 451
.650" .650"
.700" 297 .700" 479
.750" .750"
.800" 308 .800" 488
.900" 314 .900" 488


What would the best combination be? How much horsepower can it make? Is a hydraulic roller going to peter out too soon? How much lift and RPM would a hydraulic cam accommodate? Probably not enough, but looking for what others have experienced. Occasionally checking lash on a solid roller isn't to much work anyway.

Would pump gas friendly compression turn it into a dud? Is it worth giving up the power for the convenience of pump gas? What would the max pump gas compression be?

E85 is out because there is not a reliable supply on drag and drive events.

Thanks, Joel

You definitely are getting old. I’d still go solid roller over hydraulic. Not sure you even can go hydraulic with that block?

I’d look at Chips engine as a guide.
He’s running a mild solid roller, and has driven enough miles with it to go at least a couple of Drag n Drive events.

Imo, Running a HR cam and HR lifters in an application like that is going to be leaving power on the table.
I think the lifters would give up before you reached the end of the usable power curve.

I'm sure you're talking about a bigger and more contemporary Hemi than mine, but one neat thing about the Gen 2 is they like CR.
My 438" was 10.8 static, ran a pretty big for the time (.547 & ??? lift) dual-pattern Crower SFT, and was fine on pump 91 with an aggressive advance curve + vacuum advance.
It didn't make much vacuum @ idle, made 540HP @ 6,000 (and climbing) - moved my 4-speed 4.10 geared street Road Runner quite well, like 11s...
The whole point of the Hemi chamber design was to make power on crappy gas.

Can you point me to where I can find info on Chips Hemi?

I’m sure a PM would get all your questions answered.

I realize you know this already, but basically you’re balancing power vs reliability.
The milder everything is, the more reliable it is……. And the less power it makes.

It’s not what I would consider a platform that’s tailored towards easy roadside repairs((and you’re unlikely going to find competitors with available usable spare parts), so chose the combo carefully.

I think 11-1 is doable maybe a bit more. I love my 605, it's only 10.4-1 has small heads,, fairly large solid roller, a Weiand Tunnelram. It's very streetable and tries to kill me every chance it gets.
The motor peaks at 5782 but carries over 800 hp past 6600.

Mine is pretty basic w/ heads that aren't nearly as good as your Stage V heads, Joel.
575", 4.51" bore, 4.5" stroke. KB block, Callies magnum crank, Oliver steel 7.00" rods, Diamond pistons. My combo is nitrous friendly, so there are a couple areas that could be better optimized if it were going to be naturally aspirated only.
I have older Mopar Performance aluminum heads, CNC ported by MCH, max flow 430 cfm on the intake.
Cam by Dwayne. .673"/.652", 276/284 at fifty, 112 LSA. Solid roller. Isky Red Zone lifters w/ needle bearings. 3/8" .134" wall Manton pushrods, KB rocker stands, DLI roller rockers. PAC 1243 springs.
It was always intended to be run on 93 octane pump gas. I admit I never checked the compression when I originally built it. It was supposed to be around 11:1. Never heard any audible pinging, but it didn't run nearly as well in hot weather.
I hurt some pistons on nitrous in 2019. Got a new set...same style, just minor changes. I checked the compression and it's 12.6:1. Still runs great in cool weather.

Has been 9.69 at 142 mph on motor only at 3800 lbs w/ a sluggish 1.43 sixty foot. It has a 4000 stall nitrous converter and 3.54 gear in it. It's been mid 8s on nitrous.
It went 9.54 at 140.4 mph (1.32 sixty foot) at 3800 lbs w/ a 5000 stall and 4.10 gear when I was running it naturally aspirated.

FWIW...I usually check the lash once a year. It rarely needs any adjusting.
I used to drive the car a lot, but haven't driven it much at all in the past several years. I've been running this hemi since 2006.

Chip, what have you found is the best shift point when running N/A?

Not that I’m any kind of DnD expert, but here’s how I would approach a build for that.

Guesstimate about how much power you’d like to build, with the basic combo you’re considering.
Outline a parts list of what it would take to achieve that goal.
Then realistically assess whether it’s feasible that combo of parts would last 1000 street miles, or not.
If not, what would need to be changed to improve the likelihood of it surviving.
The answer to that might be changing out a few items that would result in less power.
Then the decision needs to be made whether you lean towards the power ……. or the reliability.

For what it’s worth, when I built and all aluminum hemi for my buds street car, Tim Banning told me that he had found that the pushrod angle on a Hemi was too severe for a hyd roller. So we used a mild cam and solid rollers and adjusted it a little tighter than normal. It seems to be quieter than I would expect.

We've chatted about it before, but Chip, your combo is pretty much perfect for a street car. Impressed that a 1000 rpm tighter converter and a swap to 3.54's only lost 2 tenths on motor!

12.6:1 is a little spicy on pump gas, lol

Most would say mine is not streetable. However, those that know me. I drive it all over along with all of my other cars everywhere. Chips Cuda and my blue Challenger and our combo's are very similar. He has more cubes. I run a bigger cam, higher convertor and higher gear and much more spray.

Dwayne...6800 rpm shifts and cross the stripe around 7100-7200...motor only.

Blus...I was surprised it ran that good on motor because it felt like such a turd launching, lol. FWIW...my all motor bests were on 100% 93 octane. I think 12:1 is doable with a pump gas hemi. Seems like mine is close to the limit...it only seems to be an issue in hot weather.

Thanks for all of the replies, very helpful!

With a KB raised cam block, lots of stroke fits. Does additional stroke over four and a half accomplish much on a naturally aspirated motor?

Just my , it's more cubes so go for it! I'm certainly no pro, but the extra stroke should lower the powerband...less rpm makes for a happier street combo.

Thanks.
As I suspected, even with the relatively mild cam, the best performance comes at an rpm that’s going to be difficult to achieve with HR lifters(in that platform).

Not just that, if you just float hydraulic lifters just a little, the intake & exhaust valves can hit, and spell disaster. Hemis rev very quickly. Not a chance I would take.

If you have a raised cam block you can do a 5" crank otherwise it's a 4.75". I'd put as much stroke in it as the block will allow.