87 Octane 383 by Scott Parkhurst

[68Formula]

Was there ever a followup. I have the original build information but nothing saying if it was a success or testing to prove it was optimized for 87 Octane. It was featured in PHR and Engine Masters.

Thanks.

[Scott Parkhurst]

Oh, it's a success...

We tested a few different parts while on the dyno, and what you saw in the story was the best results of what we tested.

I left PHR soon afterwards for greener pastures, and the 383 is currently under the hood of my '67 Chevelle wagon. The factory Powerglide didn't like the new power much (LOL) so the car underwent a transmission transfusion almost immediately upon my arrival in my new state. The ATS-crafted T56 swap is bitchin'. Knowing the original 10-bolt one-legger wouldn't like this big power/6-speed business, a Currie 9-inch soon replaced it. A Denny's driveshaft is being crafted now to connect them, and then it'll be time to dial in the new combo.

Naturally, the headers I've got in the car don't like the AFR angle-plug heads, so a new exhaust will follow...and the stock fuel tank (with it's 5/16-inch fuel line) will soon prove insufficient, so a fuel system upgrade is in order...and there's the 150-horse nitrous setup...that'll get plumbed in with the new fuel system...and...and...

You get the idea. The plan was good, the engine hauls on 87, and I have to finish building the rest of the car around its capabilities to really see what it's fully capable of delivering. The "round" of mods I've outlined should give me the chance to do so. The car still has 'stock' (rebuilt, with custom coils, adjustable shocks, and 12-inch discs) front suspension, which will be upgraded next. The rear suspension is ready to rock.

The interior is actually pretty good as-is. The body and paint are last on the list, and I'm debating how much of the car to blow apart to accomplish this. Once the existing paint is removed, I'll make that call. Until then, it's a work-in-progress...and it's all being built around the suprising capabilities of that engine.

Credit the good heads, coatings, and solid roller for the results. I did.

I'll keep this board updated...and once it's where I think it should be (after the big expensive parts are all in place, and before paint), who knows? I might go looking for PHR Camaros on a road course or drag strip somewhere...lol!

I'll be doing more stories about it all on the pages of my new magazine.

Thanks for the interest. PM me here anytime if you've got more questions.

~SP~

[68Formula]

Thanks Scott. That was an article that I was really interested in before it even came out. Glad to see someone put the theory to the test. And the Engine Masters Series was excellent. I hope some of the cylinderhead and piston modifications trickle down into the standard aftermarket technology.

One thing I didn't get to see was what kind of power the 87 Octane 383 put out. Plus, I would think if an engine is built for a specific octane level, it should perform best on that fuel. So I would've loved to see dyno runs with 87, 89 and 91 octane (with the fuel and timing optimized of course). The most tricky part, would probably be ensuring the fuel quality so as not to introduce other variables (such as ethanal, water content, RVP, etc.)

Any chance that was done, and I just missed the followup (probably not as I think I had already started my PHR "prescription" at the time). I'm sure with enough research I could figure it out, but what did your DCR work out to if you happen to have that handy?

I was very sorry to see you go, but my heartfelt congratulations on your new life.

[Scott Parkhurst]

The story (with dyno chart) is here:

http://www.compcams.com/Community/Articles/Details.asp?ID=1945664039

You'll see it made more than 400 ft-lbs by 3,500 rpm, torque peaked right at 500 ft-lbs (at 4,900), it had 500 horses before 5,400 rpm, and horsepower peaked at 545 (at 6,300). I planned for a 6,500 rpm redline (or shift point) so it did everything I wanted...and more importantly...at the rpm I wanted it to happen.

We didn't test with 91 octane. All the work was done with 87 because we had one day on the dyno and I wanted to try a few different rocker combinations (1.5:1 and 1.6:1 on both the intake and exhaust sides) but having 1.6:1 rockers on both intake and exhaust sides made the best overall power. We tried open, 4-hole, and 4-hole-to-open carb spacers, with the tapered 4-hole-to-open making the best average and peak power. We then ran out of time, and no further tests could be done. We had one more full day, and it was used to dial in the "twin" 355 built with identical parts, except of course for the stroke on the crank and the corresponding piston to match it. Both had 6-inch rods and 9.7:1 compression, though.

The solid roller didn't bleed off much compression down low, so the static and dynamic compression numbers should be quite comparable. I didn't play that game on this engine. Rather, I designed it with efficiency in mind and relied on an efficient chamber with coatings to spread the heat evenly and avoid hot spots. A good MSD ignition helps too. The coated valves help as well. I learned all this stuff from the Engine Masters guys, and simply applied it to a lower class of engine and a lower octane number. My compression was rather conservative, but I was able to use all of it with the coated AFR heads. The solid roller sacrificed no power, and the engine's lack of idle vacuum may be it's only major flaw. Frankly, I'm just not running any vacuum accessories and letting it do it's thing. I've got a stick behind it, so I'm no slave to the torque converter, and the idle is plan nasty sounding. Response is crisp and instant. But, there's no usable vacuum at a choppy 800 rpm.

As far as I know, the "twin" 87-octane 355 has yet to run in a chassis, but I'm out of the loop on that anymore. I know it has an assignment and should be happy there.

Thanks for the congrats and the new life is everything I'd hoped it would be. I'm happily married with a great house and a great job, and the new magazine is growing at a pretty incredible rate.

If you'd like any advice on doing something similar with an engine of yours, I'll help you all I can.

~SP~

[DeepBlue68]

Hey, Scott, I've got a couople questions for you. After reading the article, I got really excited about doing a build like that and started researching all the parts you used. One thing I didn't see in the article - which Lunati rotating assembly did you use? Flat top or domed pistons? Forged or billet rods? There are like 7 or 8 Lunati rotating assemblies (part #'s EA60 - EA68), and I couldn't tell which one you used. Also, can you give a rough price on the Calico CT2 coating? I have no idea what that would cost to have done. Do you think that would help on just about any engine, regardless of the intended octane?

That was a really sweet article, but after about 30 minutes of research, it became apparent to me that I'd never be able to afford it. From what I could tell, you had at least $4,500 just in the block, rotating assembly, and heads. Then there's a hundred other things needed to finish the engine, and I can't imagine the whole thing completed costing less than $7- or $8,000. But I still learned a lot. In the end, I figure I'd be better off to buy a $4,500 complete crate engine and run it on premium b/c it'd take a lot of miles to make up probably $3- or $4,000 in extra building costs. Not trying to sound like an a**, just the conclusion I came to for my own financial situation. But I'd definitely like to hear more about the engine as you continue with the build! Thanks for the update!

[68Formula]

Don't know about Calico, but here's the costs for Swain: http://www.swaintech.com/store.asp?pid=10971
Keep in mind anytime you can maximize heat in the chamber, minimize heat above the intake valve, and improve exhaust flow you'll see a power improvement due to cylinder filling. So the coatings are not just for allowing a the use of lower octane but improving power output as well.

I'd also think it would be difficult to find a smallblock crate motor for $4500 that puts out an honest 545hp and 500ft-lbs of torque.

You may be able to shortcut a little by buying Mahle pistons that come precoated and thermal coat just the chambers and valve heads.

[Scott Parkhurst]

Hey, Scott, I've got a couople questions for you. After reading the article, I got really excited about doing a build like that and started researching all the parts you used. One thing I didn't see in the article - which Lunati rotating assembly did you use? Flat top or domed pistons?

I used forged flat-top pistons

Forged or billet rods?

Forged

There are like 7 or 8 Lunati rotating assemblies (part #'s EA60 - EA68), and I couldn't tell which one you used. Also, can you give a rough price on the Calico CT2 coating? I have no idea what that would cost to have done.

Calico charges based on many factors. I sent a bunch of stuff to them at once (which helps pricing) but I wanted some things coated with thermal barriers (valves, chambers, ports) and other things coated with anti-friction (springs). I also got a bit of a price break because it was for a magazine story. I'd suggest you call Calico and try to package everything you want coated into a single order. Like plating and other such "treatments" the price per-part goes down when more parts are included.

Do you think that would help on just about any engine, regardless of the intended octane?

I do, without question. The properties of the coatings offer you a level of thermal control. For instance, by coating the intake ports, the cool incoming air/fuel charge is escorted into the chamber through the insulated port and past the insulated valve. Once it's lit, the heat is more evenly-distributed across the coated chamber/piston top and valve faces. Then, the spent exhaust is escorted out of the engine through the coated exhaust port to the coated header. You are controlling the heat inside the engine, which keeps temps more consistent and aids other areas too- like cooling (to a minor degree) and the loss of heat in aluminum heads. It's been said forever that iron heads make more power because of the inherent heat loss through aluminum chambers. Well..coat that chamber with ceramic, and guess what...the heat stays where we like it to be, and we still get the weight savings of aluminum. It's almost the best of both worlds. (I only say "almost" because it's still not cheap).

The anti-friction coatings (recommended for piston skirts, valve springs, and all engine bearings) keep temps down, releive some stress on the parts, and require less power to turn (so more power can get to the flywheel). Naturally, durability and longevity increase too. Less friction is always better.

That was a really sweet article, but after about 30 minutes of research, it became apparent to me that I'd never be able to afford it. From what I could tell, you had at least $4,500 just in the block, rotating assembly, and heads.

The block was a factory 4-bolt truck block I got for like $50 and had fully machined. By choosing the pre-balanced matched rotating assembly, I saved on balancing costs. The heads are the CNC-finished versions, so they were not touched after purchase except for the coatings. Your cost estimate is only a little high- I was into the longblock for about 4K.

Then there's a hundred other things needed to finish the engine, and I can't imagine the whole thing completed costing less than $7- or $8,000.

Considering I made a genuine effort to use parts untouched (out of the box) including the intake, I'd guess closer to $5500-6000. The reason I was committed to unmodified parts (except where absolutely necessary, like in the oil pan baffling and the fibrous cam button) was so my results could be easily duplicated. One of the largest gripes I have ever heard as a magazine guy has been "But I can't do what you did and have this custom-fabbed and that custom-made etc." So, I set out to create an absolute package that could be duplicated by anyone. Yes, the initial investment is higher than I'd hoped it would be, but considering how often aftermarket performance parts require further modifications to both fit and function once they've been purchased (even back to the balancing on the rotating assembly) there are almost always additional costs beyond the purchase price. This engine has none of those hidden expenses.

But I still learned a lot. In the end, I figure I'd be better off to buy a $4,500 complete crate engine and run it on premium b/c it'd take a lot of miles to make up probably $3- or $4,000 in extra building costs.

You may be right. But, consider what I wrote above, and also understand that what I was doing was a genuine experiment on my part to see how much usable power I could get from carefully designing a true performance engine to run on 87 octane. Because of its "experimental" nature I knew it wouldn't be "cheap". But, like you, I learned a lot. The Engine Masters Challenge engines aren't cheap either, but they help us all learn a lot.

Not trying to sound like an a**, just the conclusion I came to for my own financial situation.

I understand completely. If you adapt any of what you learned as a result of my experiment to whatever engine you choose to use, and you see benefit as a result, I will once again feel I've done a good job at what I do. I was hoping to help real guys make more power with their own engines, in whole or in part, and if that happens, we all win.

But I'd definitely like to hear more about the engine as you continue with the build! Thanks for the update!

Thanks for really reading it, and wanting to understand!

~SP~

[USAZR1]

Excellent article,Scott. I'm trying to decide whether to build a 383" or 406" sbc that will run well on 87octane,too. Can buy a standard bore 400" two bolt block for $250 or a late model 350" roller four bolt block for $200. The extra cubes of the 400" block is appealing but so is the capability to have cheap roller cam ability on the 350" block.

[Scott Parkhurst]

Excellent article,Scott. I'm trying to decide whether to build a 383" or 406" sbc that will run well on 87octane,too. Can buy a standard bore 400" two bolt block for $250 or a late model 350" roller four bolt block for $200. The extra cubes of the 400" block is appealing but so is the capability to have cheap roller cam ability on the 350" block.

You can't go wrong either way - It just depends what you need it to do.

I'll tell you this- If I would have had a 400 2-bolt block at my disposal before I did the 383 story, I'd have used it! The 2-bolt blocks are plenty strong- Just upgrade to ARP main studs and you're fine. I'd still go with the Lunati reciprocating assembly though- It's all forged, and its internally-balanced so all the queer stuff about the 400 crank (balancers/flywheels) is eliminated. The internally-balanced 350-type stuff is everywhere and cheaper.

Naturally, you'd address the steam holes and drill the heads as required, and cooling shouldn't be a probelm.

Otherwise, I'd have used all the same stuff, and probably generated even higher average and peak numbers. Cubes have a way of doing that...

I'd still choose to run a solid roller. The research Comp did showed a solid roller with identical lift and duration numbers offered a 15 percent gain in curtain area over a hydraulic roller. In an application like this, you simply cannot leave that 15 percent on the table. The improved lubrication on modern solid roller lifters has made them more reliable, so I'd get a set of the latest and greatest for the 406. I used Comps, but Isky and Crower also have excellent new lubricated solid roller lifters capable of life in a true street engine.

~SP~

[USAZR1]

I want a midrange tq monster to pull my p-t 69 Elky around. Since the car can be a daily driver,I really don't trust solid rollers. The jury is still out on the new stuff and I don't have the funds to be a guinea pig. A good hyd roller valvetrain should easily make good power up to 6K rpm or so w/o the worries. What I'm shooting for is around 400hp and 450ft/lbs of torque,with good vacuum to run my power accessories and yet still able to get decent fuel mileage.
As for cost,I would like to get out for less than for $5K,if possible.

[68Formula]

The solid roller sacrificed no power, and the engine's lack of idle vacuum may be it's only major flaw. Frankly, I'm just not running any vacuum accessories and letting it do it's thing. I've got a stick behind it, so I'm no slave to the torque converter, and the idle is plan nasty sounding. Response is crisp and instant. But, there's no usable vacuum at a choppy 800 rpm.


Scott,
I've found that in some cases running the vacuum advance to manifold has improved idle stability. I'm curious if you've tried that. You'll need to slightly readadjust your idle speed and mixture of course. I'd be interested if you've tried this, or if not at least consider trying it to further improve the engine efficiency.
Thanks,
Mike

[Scott Parkhurst]

That was a really sweet article, but after about 30 minutes of research, it became apparent to me that I'd never be able to afford it. From what I could tell, you had at least $4,500 just in the block, rotating assembly, and heads. Then there's a hundred other things needed to finish the engine, and I can't imagine the whole thing completed costing less than $7- or $8,000. But I still learned a lot. In the end, I figure I'd be better off to buy a $4,500 complete crate engine and run it on premium b/c it'd take a lot of miles to make up probably $3- or $4,000 in extra building costs. Not trying to sound like an a**, just the conclusion I came to for my own financial situation. But I'd definitely like to hear more about the engine as you continue with the build! Thanks for the update!

Deep Blue,

Consider the LS option by comparison.
PHR developed an LS2 to make comparable power on 91, and the pricetag is significantly "different"-

https://www.pro-touring.com/forum/showthread.php?t=18392

http://www.lateral-g.net/forums/showthread.php4?t=4423

Read the entire Lateral-G thread- I did a cost check.

It's obviously possible to have a 550-ish hp SBC on pump gas, but I must conclude it's still cheaper to do a "techie" Gen1 383 with a carb if you want to keep costs at an attainable level.

I love the LS-series engines as much as anyone, but if you really want to get down to power-per-dollar, it's tough to beat the old-school stuff...at least at this particular point in time. There is no question the LS-series engines will become more plentiful and less expensive as time passes and more of them hit the road and become available, but right now, I'm still grounded in the belief an early SBC can build more horsepower-per-dollar when the homework is done and the engine is researched and built effectively.

My $6,500 87-octane engine is still a good 545-horse alternative to a "bolt-together" LS2 91-octane engine for $13,500.

FYI- these two engines were both tested on the same dyno, so the power figures are comparable.

~SP~

[USAZR1]

I (http://I) love the LS-series engines as much as anyone, but if you really want to get down to power-per-dollar, it's tough to beat the old-school stuff...at least at this particular point in time. There is no question the LS-series engines will become more plentiful and less expensive as time passes and more of them hit the road and become available, but right now, I'm still grounded in the belief an early SBC can build more horsepower-per-dollar when the homework is done and the engine is researched and built effectively.
~SP~

I definitely agree with you on this,Scott. Something else that makes a first gen sbc attractive to us budget builders is the initial buy-in costs. It seems to cost a lot more just to get started on a LSx engine and there aren't many parts bargains.

[Scott Parkhurst]

Hey Mike- It's all relevant. You started an excellent thread...so excellent that some others had some great questions..and the timing was good too, since another topic has been posted at the same time about an engine making similar power at double the price that'll require at least 91-octane.

I know you're just joking with the chopped liver post, but with the cost of gas escalating so radically of late, the 87-octane option is more relevant than ever. The popularity of LS-series engines is also on the rise, with "fuel economy" being one of the big selling points on the new engines.

Is it just me, or could you buy an awful lot of 87-octane gas with the additional funds it required to build an LS-series engine to make comparable power to this 383? And it required premium fuel to do it.

Would there be another 30 horses in the 383 if it were tuned to run optimally on 91? Maybe- but if I'd planned to run it on 91, I would have added a bit more compression (it's at 9.7:1 now for 87- I would have gone to 10:1 for 91). So, this isn't really relevant to the discussion.

Still - this 383, backed with a 6-speed T56, should be able to deliver solid mileage in the high-teens. I am anxious to find out for certain over the long term.

Thanks for starting this thread at this time Mike. It's been an eye opener- even for me.

~SP~

[68Formula]

No, see I was joking because my 4th post, I asked about trying vacuum advance to improve idle stability, and you didn't answer the question. And then, I made the joke after my question was missed and then ...
:banghead:

Oh well. Hey, I got the first stuff answered and I really appreciated that (learned even more than just the original article). Long live Engine Masters.

Thanks again,
Mike

[Scott Parkhurst]

Oh - that..

Well - I've connected the vacuum advance, and the idle is 'fine' with regard to stability, but it's still 'nasty' in a crisp, staccato kind of way.

Vacuum signal is still insufficient for, let's say, power brakes. I'm glad I have a stick- although I was able to make it run just fine with a bone-stock Powerglide (the original '67 trans/converter) when I first swapped it in. But, I couldn't hammer the throttle too deeply...that greasy 'Glide wasn't having it.
Dropping it into gear wasn't too horrible though, but with a stock converter (especially a crappy stock converter like the Powerglide unit from '67) it wasn't loading too heavily on the motor.

Still - I will continue the fine-tuning regimen until I'm convinced it's as good as it'll get. The instant throttle response and overal stability of the choppy idle tells me I'm pretty close.

Thanks again- !

~SP~

[Beegs]

My $6,500 87-octane engine is still a good 545-horse alternative to a "bolt-together" LS2 91-octane engine for $13,500

Scott, is $6500 carb to pan? I have a 350 SBC currently, was contemplating 427 SBC Nelson Racing but if I use my 350 block and could be in it for that kind of money it makes it attractive.

[69protour]

Hey Mike, great thread! I've got a couple ?'s for Scott. Last year I had a 383 built by a good friend and great engine builder. I'll list what I have in mine and would like your imput about running 87 octane. Eagle rotating assembly, with 6" rods, D-dish pistons, Dart 200's-64cc angle plug heads,1.5 roller rockers, cam specs. Int-251,Ex-256 Dur. @ 50. Lift, Int-538, Ex-544. LCC-106. Also did a 4-7 swap. I think the compression comes out at about 9.6? Victor jr. intake with a 650 Mighty Demon carb. Hooker super comps. MSD E-curve dist. Internally balanced also. I've been putting 92 octane in it but would like to think that with that low of compression I could get away with the 87? I've got timing at 17 degrees with 15 degrees total advance. Thanks again for all your great knowlage. Trond.
P.S. In the long block I've got about 6500.00. So not cheap but one runnin S.O.B. :) and smooth too!!!

[Scott Parkhurst]

Hey Mike, great thread! I've got a couple ?'s for Scott. Last year I had a 383 built by a good friend and great engine builder. I'll list what I have in mine and would like your imput about running 87 octane. Eagle rotating assembly, with 6" rods, D-dish pistons, Dart 200's-64cc angle plug heads,1.5 roller rockers, cam specs. Int-251,Ex-256 Dur. @ 50. Lift, Int-538, Ex-544. LCC-106. Also did a 4-7 swap. I think the compression comes out at about 9.6? Victor jr. intake with a 650 Mighty Demon carb. Hooker super comps. MSD E-curve dist. Internally balanced also. I've been putting 92 octane in it but would like to think that with that low of compression I could get away with the 87? I've got timing at 17 degrees with 15 degrees total advance. Thanks again for all your great knowlage. Trond.
P.S. In the long block I've got about 6500.00. So not cheap but one runnin S.O.B. :) and smooth too!!!



I would sure try running 87 in it, and creep up on the timing. I bet you'll be suprised how little you'll "lose" going to the lower-octane fuel.

If you had coated chambers etc, I bet you wouldn't have to change a thing.

Try it and see how far you can push it. If you enjoy driving the car on a regular basis, you can run 87 daily and upgrde to the higher-octane tuneup for the weekends or evenings when you'll want every single pony. I don't have to tell you - you'll save a bunch on gas this way.

Look into an Air-Gap intake, too...there's power in there.

~SP~