Tell me about your 383 Stroker engines

[djmachinist]

I'm in the process of having a small block 383 Stroker engine built. I'm starting with my ZZ4 350 block and adding an Eagle balanced 383 rotating assembly kit consisting of a forged steel crank, SIR rods and forged pistons.

I'm adding a Edelbrock Top End power package consisting of the Etec 170 alum heads, performer rpm air gap intake, and edelbrock 2204 full roller cam.
234/238 duration @ 0.050, lift @ 0.538/0.548. Lunati 1.5 alum. roller rocker arms. I'm topping it off with a Quickfuel SS 680 cfm carb with elect. choke and vacuum secondaries.

CR=10.25:1

HEI Dist. and Sanderson Block hugger headers exhaust running through Magnaflow mufflers.

My engine builder is telling me this combination should put out around 450 to 460 hp/ 430 ft/lb of torque.

I already have a Pheonix built 700R4 OD tranny w/ 373 positrac rear end.
2200 stall converter.

What do you think? Is my engine builder being overly optimistic?

Thanks,
Dale

[POPO1984]

Im no wiz when it comes to engines but I think the 170cc heads are kinda small for that cam. I am gonna run a 195cc head on my 383 with a 228/234 hr cam .530 lift.

[djmachinist]

Originally Posted by POPO1984

Im no wiz when it comes to engines but I think the 170cc heads are kinda small for that cam. I am gonna run a 195cc head on my 383 with a 228/234 hr cam .530 lift.

Yeah, thats what I thought but this is Edelbrock's dyno matched kit # 2097. When I called Edelbrock's tech line, they told me that I could use the Etec 200 heads which have the bigger valves, however the Etec 170 heads made more torque when matched with the edelbrock 2204 cam. I think I will trust Edelbrock with this one.

However, it looks like your combo of cam and Heads should give good results also.

Dale

[POPO1984]

I have been told by several people that it should be good for 480 hp atleast
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[POPO1984]

By the way whos doing your engine
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[Marv D]

The e-tech's are kick BUTT heads for what they are. We put a set of the 170cc e-tec's on a 406 and ran 11.2 @ 119 in a 70's Nova with nothing but a Comp 284XE hydraulic cam. That thing should NOT have liked the little 170 heads, but,, the numbers say different. BUT do keep in mind... the motor fell flat on it's face around 6200. The cam wanted more RPM, the heads just wern't up top the task. If he had the 200cc E-tecs I'm quite sure it would have been a 10 second car that was driven 100 miles each way to the track.

I'm with Popo,, for my money I'd go with the 200cc E-tecs if I was looking at any track time. If it's just a SERIOUS street motor,,, the 170's ought to work if you keep the rpm's down. With that hydraulic roller cam it's going to be RPM limited anyways, so probably a decent match.

450-480 is a safe bet I'd say. But remember that is GROSS HP. Once you start adding water pumps, alternators, mufflers and chewing up torque through the converter and drive train,,, I'd be very happy with 390-400 at the drive wheels with that combination.

[djmachinist]

Originally Posted by Marv D

The e-tech's are kick BUTT heads for what they are. We put a set of the 170cc e-tec's on a 406 and ran 11.2 @ 119 in a 70's Nova with nothing but a Comp 284XE hydraulic cam. That thing should NOT have liked the little 170 heads, but,, the numbers say different. BUT do keep in mind... the motor fell flat on it's face around 6200. The cam wanted more RPM, the heads just wern't up top the task. If he had the 200cc E-tecs I'm quite sure it would have been a 10 second car that was driven 100 miles each way to the track.

I'm with Popo1984,, for my money I'd go with the 200cc E-tecs if I was looking at any track time. If it's just a SERIOUS street motor,,, the 170's ought to work if you keep the rpm's down. With that hydraulic roller cam it's going to be RPM limited anyways, so probably a decent match.

450-480 is a safe bet I'd say. But remember that is GROSS HP. Once you start adding water pumps, alternators, mufflers and chewing up torque through the converter and drive train,,, I'd be very happy with 390-400 at the drive wheels with that combination.

I really appreciate the info. This is just a serious Street motor not a drag motor. I went with the Etec 170's instead of the 200's because Edelbrock told me combined with a 650 cfm carb, the 170 heads would have much better mid range Torque numbers. This thing also must run on 92 octane Pump Gas. I do not want to be going to my local speed shop to get 110 racing fuel to spike my pump gas just so I can drive it on the street. I want this truck to be capable of being a daily driver if I want it to. If the compression ratio is to high and the edelbrock cam is too much to support the streetabilty of the truck, I will back out on the CR and cam specs.

Oh....Popo1984...Joe at G & G Performance is building the engine. Paul Welch at PAR Performance is doing the actual engine Install and Paul is one of the best Tuners in Houston. Paul and Joe have worked together for years. They both assure me with careful carb and Distributor advance curve work, this engine will run on Pump gas with a 10.25 CR.

Thanks,
Dale

[Marv D]

I agree 100%,, 10.25 with aluminum heads, the cam spec says intake closing is 44 after,,, your dynamic compression should be plenty tolerable of pump gas,,, that is all assuming the 10.25 is a true calculated static compression from measured volumes?

I do want to touch on something again,,,, you only make power by moving air and fuel into, and out of the chambers. The more you move, the more power you make,, simple fact. And a 200cc port is going to 'allow' more air to flow than a 170cc port. You ARE leaving potential power on the table with the 170 e-tec's,, in favor of something that I don't know I 'totally' agree with the thought that the 170 e-tec's offer more mid rpm torque. The whole Edelbrock line concentrates on this thing called 'port velocity'. Without good port velocity fuel falls out of suspension, you get poor cylinder filling, reversion, all sorts of things that cost power. I have never seen any real back-to-back comparisons of the E-tec 170 and 200, but I would suspect it's the great port velocity of the e-tec 170 that did so great on 406 I built for my friend. I am quite confident the 200's are going to share the same port technology and high speed velocity of it's little 170cc brother. I'm not convinced the 200 would be a 'bad' choice for a larger small block like this.

What all this is saying,, FOR WHAT YOU ARE DESCRIBING... the 170 is probably, and may well be the better choice. If you will almost never see the high side of 4000rpm, the 170cc version will fill the bill on the street very VERY nicely. BUT,, remember,, this 450+HP magic number is most likely up around 6200+rpm. NOT at 4000. IMO any 170cc port, no matter how great it's port technology and velocity is, is going to be borderline trying to feed a 380+ cubic inch small block up in the upper 6000rpm range.

You have a bit of a catch-22 deal going on IMO. Horsepower is simply torque , times RPM, divided by 5252

Your 420 ft pounds of proposed torque,, at 6200rpm will be real close to 500HP

at a more believable small block torque peak of 4200-4600rpm ,,, more like 330-360HP

When you give up RPMs, you give up horsepower. And it's apparent your giving up 'potential' horsepower with the head that is going to inhibit rpm's in favor or 'potential' mid rpm torque. All just something to think about.

I don't know the arrangement you have with your builder, or if they have a good superflo dyno,, but for the $500 most shops charge,, a engine dyno session is worth EVERY PENNY if for nothing but to tune the motor to a sharp tune. Take YOUR headers, YOUR carb, YOUR distributor and spend a few hours on the dyno and it accomplishes a multitude of things. First it dispels any HP and torque 'CLAIMS', it breaks in the motor, finds any assembly errors / leaks, and potential problems. And,,,, spending a few hours / few hundred bucks getting the tune RIGHT may save many fold that much in wasted fuel and other items you waste searching for the right tune. And if they tell you they have dyno'd one just like it and know what it makes, NO THEY HAVENT, not with YOUR carb and YOUR headers and YOUR exact combination of parts and pieces going into YOUR chassis.

[Super73]

Not knowing anything about the heads, I would say the 170cc is too small, but.... With smaller runners, come more velocity and more TQ.

Do the 170cc heads have a smaller intake valve than the 200cc heads? That could aid to unshrouding the valve allowing more use of the actual rated flow numbers.

I'm sure there is a point in which RPM says the heads are too small.

Originally Posted by Marv D

With that hydraulic roller cam it's going to be RPM limited anyways,

Marv, I am very curious as to why you say a hyd cammed motor is going to be limited in RPM.. Obviously everything has it's limits, but where do you feel hyd lifters ceiling is?

I know we briefly discussed this before, and I used LS stuff as an example, but I personally feel SBC or LS1 the lifters ability to stay ok has to do with total vavletrain weight, spring pressures and lobe design. If a soft lobe was used, I think you could run 8k with a decent spring. I also think if it was more aggressive, with a great spring your could run a hyd cam well in to the 7,500 range.

[Marv D]

Speaking mostly from what the cam grinders expect from most of these hydraulic roller profiles Shaun, Well the 'advertised' effective rpm range and the issues I've had with even a hydraulic roller and a rev kit. I've just beat the CRAP out of a cam and roller trying to take the heavy hydraulic roller lifter to 7000. Jay Allen told me the hydraulic roller will take 400 psi of spring pressure and most of the agressive lobes start lifter toss well before the max rpm range with milder springs.

I'm wondering if the 1.7 rocker ratio of the LS motors offer better lifter control than our old Gen-1 small blocks? It only makes sense(in my feeble mind) that with more leverage on one side of the rocker pushing the valve down,, the spring has to 'push back' on the lifter side helping the lifter follow the cam and not bounce? Not sure. What's your thoughts on that?

[Super73]

400lbs of spring pressure??
Is this at the lifter?
Does he give a different spring pressure based on rocker ratio?

Comp 918 single spring which was designed for the LS motor is at 367lbs open. With a
1.7 ratio that is 623.9lbs at the lifter.
400lb on a 1.5 is 600lbs
400 on a 1.6 is 640lbs

Comp 921's again designed for LS motors are 400lbs open. On the 1.7 that's 680lbs on the lifter.

Patriots .660" spring is in at 410lbs, 697lbs on the lifter.

I guess the problem I have is understanding the blanket statement Jay gave you. I'm sure the 1.7 ratio is helping to keep the lifter planted on the cam given equal spring rates.

The LS also I believe has a lighter valve in it do to valve stem diameter. This could have some thing to do with control.

Spring diameters tend to be more narrow, perhaps helping harmonics and aiding in control since the spring has to control a portion of it's own weight. They also tend to use a tight fit dual spring with no dampner. Idea here is the inner spring is acting like a dampner rubing the inside of the outer spring.

One area of concern for me is sideloading a lifter with added pressures. For example, I am running a bit more spring pressure than others. At .650 lift my current spring is 480lbs (816lbs on the lifter). This makes me think about roller pin and where it mounts to the lifter body. The added stress. This is actually a spring for a solid cam. My intake sees .646", exhaust .629".. With a solid cam, there is some slack built in with lash. With a hyd cam, there is no slack since the lifter is filled with oil against the plunger. There is no allowance for the lifter to start following the ramp of the cam (no slack before it takes a load). My cam is also a solid roller design. But interesting enough, the cam is less agressive from .006 to .050 than many LS designed lobes. I spent several hours with a degree wheel and a dial indicator on the lifter to get the true .006 numbers. .006 has 298*/318* and .050" has 245*/260*..

The other thing I am intriged with is lifter bleed down. I am seroiusly considering building a test rig that fist a lifter in it. Put 60lbs of oil pressure to it and see how much force in a press it takes to start colapsing the lifter once it drops bellow/above the oil gallerey. All hyd lifter bleed down, I'm curious to know how fast. Am I getting all my .646" / .629" lift at rpm? Or is the lifter bleeding down enough to where it's equal to a solid lifter with .018 / .020 lash..

[C-10 simplex]

When you take a new or reman 383 block, such as this summit block:
http://www.summitracing.com/parts/SUM-150100/ AND add a rotating assembly such as from Scat or Eagle, do you have to do any machine work? Or can you literally bolt everything in and go?

Honing?

[Super73]

I would go through it and double check ALL the tolerances before just bolting it together..

[C-10 simplex]

OK, but generally, let's say everything was checked out and found to be on-spec; i guess what i'm trying to ask is what, if any, machine shop operations are nessesary if you take a 383 block and put a 383 rotating assembly into it?

[Marv D]

Wow, this has became a great conversation on valve train tech,, sorry for dragging things so far off topic, but some really great info and thoughts here.

Jays comment was referring to the standard 23° Gen-1 SBC with a retro-fit hydraulic rollers and a reduced base circle cam. We already had a set of Crower retro-fit hydraulic rollers for one of his short duration large lift cams. Was looking for a 1.55" spring to keep it all in check without a rev kit. Why he suggested 400 pounds on the nose?? I honestly haven't a clue. Possibly that is where he felt the lifters would start to have excessive bleed down, axle fatigue, total collapse,,,, really don't know. Sounded like a good number to me as most every spring I found for a hydraulic are on the 130ish# seat pressure and 280-350ish at .6 for hydraulic cams. Figured there had to be some solid thought behind it and really just never questioned it.


c-10simplex.. let me offer something my machinist explained to me a long time ago.

An engine 'builder' takes boxes of parts and pieces, inspects, and machines as necessary to make every component fit with the proper tolerance and clearance.

An engine 'assembler' can take the motor the 'builder' created and take it all apart, replace soft parts and re-assemble.

This is what Super is getting at. 'BUILDING' a new motor from boxes of parts takes a 'builder' . You may get parts that are called' ready to bolt on' but never trust it till you yourself have disassembled, inspected, measured, and checked that it fit's 'RIGHT' .

Theoretically, the Slummit stroker blocks are ready to start dropping rotating 'assemblies' in and make a motor. But in the end,, it's YOUR responsibility to see that it all goes together right.

Especially with a stroker, nothing will EVER be a bolt together. Heck even changing the cam timing will change rod to cam clearance. If you use a cap-screw rod vs a standard GM I-beam rod you will have VERY difference clearance to the bottom of the bores, pan rail and block face. No way can they make a 'one block fit's all' offering. Too many variables. The tolerances such as the thrust surface, journal size, all SHOULD' be on spec and a bolt together. But especially wit the Eagle junk that is finish machined in China,, you better check even that. I have Eagle 4" stroke crank that was + .0007 on the rods, and - on the mains. RIGHT OUT OF THE BOX. You can never just 'trust' anything any more. And ultimately,, who is going to loose here if you don't? They may replace a bad crank, but they aren't going to replace the other parts that get destroyed when it all goes south.

[POPO1984]

Dj where is PAR Performance located

[Super73]

Marv, perhaps I should create a valvetrain technical thread and we can all add to it. Take what we have already discussed and move it there.. Might be a good start.


Popo,

You might be able to get away with a kit and putting it together, but let me tell you, I grow leary of that.

The first 347ci motor that was put together for my truck, I used a stock GM crank, Eagle rods and Diamond pistons. I had a machine shop go through it and the eagle rods were "in spec" but they were on the large side. This means the rods would of used a + sized bearing right from the start. Instead we elected to resize the rod right out of the box. The machine shop also looked over a lot of other little things for me since I did not have the tools. They gave me a complete breakdown of ring gap, all bearing tolerances, piston to wall clearence ect. Very happy with their services. I assembled the motor and double check things as I went along. Everything came out dead on.

On to the 418 build. I called a well known cookie cutter LS shop out of Texas. They sub their machine work out but probably sell 5-10 motors a week. Being anal and knowing how much N20 might go through this motor (300regularly, 500 if I get real ballsy) I elected to have them do the tolerances but leave the rings to me and ship it to me in pieces. When I got it there was a clearence sheet in it. First thing I notice was the piston to wall clearence .0004 and the ring gap .018 top .022 bottom. Might not mean much, but those are clearly NA clearences, this motor was not set up for N20. The same night, I started double checking things. I checked ALL the bores and ALL the pistons as well as ALL the bearing tolerances ect. The bearings were in but the piston to bore was not exact either. From Weisco some of the pistons ranged from 4.0765 to 4.077. This means none of them would have been "exact" since the bores were set to 4.081. Needless to say I called Weisco the piston MFG who said the rings should be .026 top /.029-.030 bottom and the piston should be min .0045, then I called the cookie cutter LS place. I told them from the begining what my intended useage was and what the tolerances were set to. They agreed to let me fix it local and foot the bill which would be a lot less than the round trip shipping. All is fixed, but my point is this came from and engine shop and was off.

I have had 2 friends get motors from local shops and both of them had major clearence issue.

One the rings had nothing for gap and destroyed the motor with in a couple hundred miles.

Another, the mains were so tight, the motor seized up with in 50 miles. When pulled apart, the crank journals looked like ruffles potato chips. When the motor came back, it had the wrong cam in it.

What I'm getting at is trust no one and no manufacture when getting a motor done. If you just put it together with out going through it and it has a major issue, is summit going to fix it for you? Are you going to be happy when you have to pull it out and spend more of your hard earned money to fix it? Motors aren't cheap.. And they can be a major headache when things go wrong. Take the 2-3 nights to really go through it.

[djmachinist]

Originally Posted by POPO1984

Dj where is PAR Performance located

PAR Performance
22955 Tomball Parkway
Tomball, Tx. 77375

713-822-8607
Paul Welch

[djmachinist]

Originally Posted by djmachinist

I'm in the process of having a small block 383 Stroker engine built. I'm starting with my ZZ4 350 block and adding an Eagle balanced 383 rotating assembly kit consisting of a forged steel crank, SIR rods and forged pistons.

I'm adding a Edelbrock Top End power package consisting of the Etec 170 alum heads, performer rpm air gap intake, and edelbrock 2204 full roller cam.
234/238 duration @ 0.050, lift @ 0.538/0.548. Lunati 1.5 alum. roller rocker arms. I'm topping it off with a Quickfuel SS 680 cfm carb with elect. choke and vacuum secondaries.

CR=10.25:1

HEI Dist. and Sanderson Block hugger headers exhaust running through Magnaflow mufflers.

My engine builder is telling me this combination should put out around 450 to 460 hp/ 430 ft/lb of torque.

I already have a Pheonix built 700R4 OD tranny w/ 373 positrac rear end.
2200 stall converter.

What do you think? Is my engine builder being overly optimistic?

Thanks,
Dale

Well, the 383 stroker is on the street now. My concern is the Compression ratio is too high for 93 octane pump gas. When I picked up the truck from the shop, it started pinging on the way home. The pinging was apparent under normal driving. The shop originally told me the static CR was going to be 10.25 to1. When Pressed about it, the shop admitted it came out 10.97 to 1. I took the truck back to the shop friday. The shop told me the timing was set at 32 deg. total advance. After four attempts, He backed the timing off to
26 deg. total advance. This did stop the pinging for the most part. I get a hint of pinging coming off a dead stop at light throttle ever so often. My question: Is the CR too high for 93 octane and it seems the timing is retarded quite a bit at 26 deg. What do you think? And what would be a good fix to lower the CR if 10.97 is indeed too high? Take the engine back down and install Dished Pistons or would a extra thick head gasket from say ICS Titan
work? The basic engine build is listed above and The CR data is:

64 cc heads
+5 cc piston volume (flat top pistons w/two reliefs)
.038 head gaskets
4.190 gasket bore
4.030 Cylinder bore
0.005 Deck height (in the hole)
3.75 Stroke
5.7 in. Rod length

Thanks,
Dale

[swb85]

Easiest/cheapest fix is a cam swap. That old edelbrock grind has a really early intake closing point, so your dynamic compression is through the roof.....way too high for pump gas. I would look at something like a comp XR288HR or something similar. It's only a few degrees bigger @ .050" than what you have now, but it will drop your dynamic compression down in the ~8.4:1 range which will run perfectly fine on 93 octane with full ignition advance.

Also, I think you'll want more stall speed than 2200rpm regardless of whether you swap cams or not.....I'd run between 2500-3000rpm if it were mine.

[POPO1984]

Your gonna have to get a different piston unless to do as stated above

[djmachinist]

Originally Posted by swb85

Easiest/cheapest fix is a cam swap. That old edelbrock grind has a really early intake closing point, so your dynamic compression is through the roof.....way too high for pump gas. I would look at something like a comp XR288HR or something similar. It's only a few degrees bigger @ .050" than what you have now, but it will drop your dynamic compression down in the ~8.4:1 range which will run perfectly fine on 93 octane with full ignition advance.

Also, I think you'll want more stall speed than 2200rpm regardless of whether you swap cams or not.....I'd run between 2500-3000rpm if it were mine.

I read your 383 build, nice engine!! You are getting that kind of miledge out of that combination, Wow!!!

Ok, After reading your 383 build, I have a plan of action:

First, I called Fel Pro and explained the problem and they suggested their Head Gasket #Z1144061 Head gasket that is 0.061 in. thick. This will bring down the Stactic CR to 10.3 to 1. Second I'm going with the the same cam you used in your 383 build, Comp cams # XR282HR. That should bring down the Dynamic CR to something reasonable. The timing should be able go up to 32 deg. or so with no problem. What do You think?

Thanks,
Dale

[swb85]

Originally Posted by djmachinist

I read your 383 build, nice engine!! You are getting that kind of miledge out of that combination, Wow!!!

Ok, After reading your 383 build, I have a plan of action:

First, I called Fel Pro and explained the problem and they suggested their Head Gasket #Z1144061 Head gasket that is 0.061 in. thick. This will bring down the Stactic CR to 10.3 to 1. Second I'm going with the the same cam you used in your 383 build, Comp cams # XR282HR. That should bring down the Dynamic CR to something reasonable. The timing should be able go up to 32 deg. or so with no problem. What do You think?

Thanks,
Dale

DO NOT change to a thicker head gasket, that will make the motor even more prone to detonation. You want to leave the head gasket alone, as it sits you've got a respectable .043" quench distance. You don't want to go any wider. The only way to correctly change static compression is either change pistons or make the combustion chamber in the heads bigger.

You've got a half point more static compression than me so you may need more cam to get your DCR down to pump gas territory, but you've got aluminum heads and 93 pump gas (we only have 91 here).....so you may be able to get away with a little more squeeze than I can.

[softballnrd27]

Be careful getting a thicker head gasket, you don't want to get your quench area too big

[softballnrd27]

swb85 beat me to it, listen to him he is smart, I asked him tons of questions and he helped me out alot.