skinny z

Saw that after I posted. Yeah, it looks to be pretty close.

ULTM8Z

No immediate plans to dyno it.. its a 100% street car driven casually on the weekends with some spirited driving every now and then.

The modified ZZ4 was very fast already before, so I'm sure I'll be really happy with the 383.

I also have a gear vendors overdrive behind my 700R4, effectively giving me an 8 speed transmission. So that'll help maximize the effectiveness of the engine's powerband.

At that point whether I find out I have 400 ftlb or 450ftlb, or whatever... won't really matter that much to me.

89fast5oh

You have posted in some of my 383 threads. Seems both our engines are very similar. Glad to see yours is up and running.

Is your 700R4 built? Mine is stock and hits second gear and it slips like a *****. I have reached out and am waiting to hear from Dana at Probuilt.

What do you have for rear end gear ratio?

Tuning the ecm yourself?

ULTM8Z

700RR4 is "built" to the extent it has some basic upgrades to it from the local transmission shop to make it capable of ~450-500 hp. Heavy duty clutches and bands and things like that... shift kit, etc. But it's not anything "race-ready" or stuff like that. I have a Hughes 2500 rpm lock converter in it as well. It's just a good stout street transmission.

3.42 axle ratio

Yep, I do my own tuning with Tunerpro/Tunercat. I have a WB O2 in the passenger side exhaust collector. I'm expecting the relatively mild cam to make it easy to get it dialed in.

Tomorrow I'm going to take the car out and run through the break-in proceedure that Scoggin Dickey recommends in their instructions (recall this is the GM HT383 short block that I started with).

ULTM8Z

Just got done with the break in procedure...

Car runs really strong. The first moderate-hard throttle pull up an on ramp it almost got away from me... nearly got sideways with it with at barely half-throttle. Kinda surprised me... Probably good I didn't put any more power into this engine than I did... lol. The 427 would have been way too much IMO ( I was contemplating a small block 427 for a bit).

Full throttle was just about out of control... This kind of power with a 70's era suspension is "interesting"
.
The good thing was the old 350 tune was nearly right on the money, just having changed the displacement constant to a 383. Just some slight tweaks to the fueling and didn't even have to mess with the spark timing.

One thing I like with the Hughes 2500 rpm converter is the car doesn't have the "trigger happy" throttle coming off the line. It's much smoother take off. I'm also getting about 14-15 inHg vacuum at 650 rpm in gear.

You can tell the top end didn't improve as much as the bottom and mid-range due to the mild cam (which is about what I was expecting). But, this is the drivabliity characteristic I was shooting for, so I'm very satisfied with it.

Thanks again to all for their advice and votes of confidence. Looking forward to enjoying the car for years to come hopefully.

Orr89RocZ

iTrader: (20)

What tires are on it? You have lca relocation brackets?

ULTM8Z

It's a 2nd gen... so it has the rear leafs.

285/40 ZR 17 Nittos

Orr89RocZ

iTrader: (20)

Ohh lol i have no idea how that works lol

get on some 555r2’s or nt05r and it will stay planted

ULTM8Z

I have 555s on there now, but I don't think they're the R2s.

To be honest, im a little afraid of having this much torque going into the drive train... it may break something. The tires losing traction is kind of a mechanical fuse for the system.

Besides I'm probably going to be a little more tempered wkth my driving... I'm nearly 50 years old and the last thing I need is a ticket or arrest for reckless driving and/or having the car impounded.

skinny z

The go to guy for the 700.
Probably many other transmissions too but I'm in the THM700/4L60 camp myself.
I did spec my own internals although that always leaves a guy second guessing.

QwkTrip

iTrader: (22)

Congrats on getting it driving!

Tires and shocks become more and more important as power level increases. That's what will keep it under control. And driving style.

Get a tire with between 0 - 200 tread wear and you'll have good traction. Double adjustable rear shocks will help keep tire planted firm to the ground. And I don't know what are the air temps where you live but it is dead of winter here and my performance tires would drive like ice at these temps. My traction improves a lot above ~80F.

The lower the tread wear the more the street will destroy the rubber in short order. Try a good 200 tread wear first and see how that goes. It's going to have a ton more traction than what you've got now (in summer). Something intended for autocross short course will get sticky without needing much heat and that will stick good on the street. Long course tires (road track) won't get enough heat on the street to perform well but it maybe will last much longer.

skinny z

For sure. I'd say conservatively that crankshaft torque is into the 450's from 2000 to 5000. It may be that I'm tuned into that number but I find it seems to be the threshold where things do start to let go. And you can bet that sticky tires intensify the effect. Many miles put on a stock 9 bolt 3.70 rear gear but once at the track with my slicks, the pinion let go on my first into the 12's pass.


Or worse. Keep it between the ditches.

ULTM8Z

Ugh... spoke too soon. Lol...Looks like the front of the transmission sprung a leak somewhere... either than the converter hub seal or the o-ring is my guess. I can see the fluid coming down the front of the transmission case.

Hopefully not a bad weld on the converter or something like that.

Any rate, nothing was leaking before I spun the rod bearing on the ZZ4, also I took the trans in to have it fully inspected after that happened, so it has to be something that occurred after that... either the converter itself or something I did on the installation.

Guess the tranny is coming down again. The seal itself looks pretty easy to change if need be, and I've gotten pretty adept at R&R-ing the transmission lately... lol.

Probably just replace the seal and the O-ring to be safe. I saw on YouTube how to do a rudimentary pressurized leak check on the converter so I'll do that as well.

drb930

I reread this whole thread again today, but didn't see this cam in the fight?
Lunati -
Advertised Duration (Int/Exh): 280/288
Duration @ .050 (Int/Exh): 226/234
Gross Valve Lift (Int/Exh): .530/.530 That's with 1.5 rockers
Gross Valve Lift with 1.6 rockers would be .565/.565
LSA/ICL: 112/106

LPE 74219 =
270/270deg. Duration@ .006" w/ 1.5 ratio rockers
.525"/.525" Gross Valve Lift w/1.5 ratio rockers
.560"/.560" Gross Valve Lift w/1.6 ratio rockers
LSA/ICL 112/108

This is not that much different than the LPE 74219 that I am running now, but -
I considering this cam for my engine to possibly go SC as they recommend a dual profile cam for SC.

Thirdgen89GTA

iTrader: (5)

that looks like the little brother to the grind I have in my GTA.


as for the comment about how older afr heads compare to their newer offerings? Night and day difference. Massive jump from the old design to the newer eliminator design. Then again, even the old ones are significantly superior to any one of the factory heads.

ULTM8Z

Got the transmission down...

Nothing obvious in terms of where the leak is coming from. Just a couple observations...

1.) I'm not liking the torque converter input shaft o-ring very much. It's not damaged or anything, but it seems a little too pliable/flimsy/soft... like it's not making a sturdy seal. It's one that Hughes sent me with the converter.

2.) A couple of the pump bolts at the 9 and 10 o'clock positions have some fluid near the base of the head. I don't know if that's just fluid being tossed around and got deposited there.

3.) I lightly pressurized the torque converter with some compressed air and didn't see any leaks coming from the weld. I got a rubber cap and and put a tiny hole in it in order to put a basketball inflater needle in to it. On a youtube video I watched, someone demo'd this and showed how fluid can leak out of bad weld.

4.) The torque converter hub OD is measuring at 1.749 to 1.751. Not sure if that's correct or not... Anyone know?

5.) Not seeing any obvious cracks in the trans housing or anything like that.

Any rate, I ordered a front seal kit. Probably replace the pump bolt seals, torque converter turbine shaft seal, and the input shaft seal.

ULTM8Z

Fixed the leak. I guess it was either main front seal, the O-ring on the input shaft for converter, or one of the the pump cover bolt O-rings. I replaced all of those and the leak appears to be gone.

Any rate, did a little more playing with the tune and I'm finding it likes quite a bit more AE in the low-mid range. Probably a function of the wide LSA on the cam (114°). In any event, you can feel seat of the pants just how flat this torque curve is with that LSA and the Miniram.

I'm starting to think you may be right. The amount of torque this thing has is ridiculous. After getting the AE dialed in, it'll blow the tires away at not even half throttle off the line.

skinny z

I would certainly think so.
I couldn't find your rear gear ratio. With the low 1st gear of the THM700, it really pours the beans to the final ratio seen at the tires.

skinny z

That's good.
I've got a freshly rebuilt 4L60 and there's a trans fluid leak near the front. I can only suspect that the used torque converter may be grooved and resulting in a leak at the front seal. Could be a nicked seal as well. I'll be doing the same as you do did trying to resolve it.

ULTM8Z

3.42 axle ratio

ULTM8Z

I'd get the 4L60E seal kit. Check the converter hub thoroughly of course. But, replace the front seal, the pump cover bolt O-rings and the input shaft O-ring for the converter.

As long as you're pulling down the transmission, may as well just change everything.

skinny z

True enough. It's due for it's 1st post rebuild fluid and filter change too. It's a very low mileage unit but the leak is aggravating.
The engine is out and at the machine shop and the transmission is soon to be on the bench.

skinny z

That's like having 4:10 gears behind a TH350. Back in the day, that was the recipe for the quicker street racers. Put a stall converter in front of that and my friends 74 Camaro was a missile. And nowhere near the torque out a 70's built 355 as compared to a 2020's version of a 383!

ULTM8Z

Yeah and with gear vendors OD crusing at around 2000 rpm at 80 mph, the mpg readout on Tunerpro was showing 28-29 mpg when highway mode fueling kicked in. Previous mileage calcs using the fill-up method proved that TP readout to be pretty accurate.

The wide LSA cam has this 383 cruising effortlessly at that speed and rpm.

ULTM8Z

Just please don't put a stock converter in there! Minimum 2500 rpm....

QwkTrip

iTrader: (22)

Did you get tires on order yet?

You'll be able to dip into the throttle pretty early in 1st gear if you buy the right tire. The Falken RT660 are my current favorite. I only drive in nice conditions so I don't care about wet traction and such. Also don't care how long the tires last. I just want grip.... lots and lots of grip.... consistently all the time. Those Falkens are the freakin' boss for performance street cars.

The really good Michelin's and stuff aren't available in our sizes. But that's too much money for me anyway.

ULTM8Z

I need to lay low on spending money for a while...lol

This was a $5000 expenditure (after selling a bunch of the old stuff).

Mrs ULTM8Z was pretty gracious about it, but I don't want to push it... lol.

Besides the tires right now are still in great shape and I'm not going around peeling out on a regular basis... its a nice turn key Street car and I'm driving it like that.

skinny z

No worries. I've a 10" TCI that flash stalls to 4000. Really nice converter. Not as good as a Yank though.

Fast355

iTrader: (2)

My 383 cruised effortlessly pushing the heavy van along with the big 232/244 @ 0.050 on a 108 LSA Lunati Bootlegger. 383s make lots of low-spees torque even with a decent sized cam.

Orr89RocZ

iTrader: (20)

Is that because of the variable lifters you had making the cam seem smaller at lower rpm? Rhoades lifters right?

Fast355

iTrader: (2)

Quite possibly a contributing factor, but at 2,500+ rpm they are already increasing lift and duration. I am geared pretty low as well.

ULTM8Z

The hot rodder in me keeps wondering if I should have gone with a bigger cam. But the "I'm gettin' old" side of me is kinda liking the 15" of vacuum idling in gear. It's a very powerful car that's also very pleasant to drive... judging by the very docile sound of it idling, you'd never guess it was making the kind torque that it is... lol.

My adjustable timing chain set I bought put me in the quandry of having to chose between 2 deg advanced or 2 deg retarded. I ended up choosing 2 deg advanced at Crower's suggestion. The factory Vortec timing chain set that came with the HT383 shortblock evidently had 4 deg retard built into it relative to Crower's cam card, which is what forced me to buy the adjustable one. I don't know how much a 4 deg retard from my current setting would do to the idle quality. But whatever... at this point I'm very happy with it.

The gear vendors OD unit giving me 8 speeds on the drivetrain keeps me where the engine is happy pretty much at all times (or at least makes available peak torque whenever/wherever I want it).

Orr89RocZ

iTrader: (20)

After tuning several combos and having a variety of cams, i decided i like big cams lol

to me that starts around 230 deg in a 350, maybe even in a 383

skinny z

Had I gone the 383 route (there's a 357 in the works as we text), with my heads (253 cfm @ .550") and 10.2:1 CR, I was looking at 278/278, 107 LSA, 103 ICL. That's only 64 degrees of overlap which is nothing for a 383. Predicted idle vacuum is 14.5".
But the smallish heads keep the cam spec in check. Peak HP RPM is estimated to be at 5400. The .050" number would be something where I'd have to decide on how much lobe intensity I'm willing to gamble with. Anywhere from 220 (which is easy on parts) to 234 (which makes more power throughout the curve) but might not have the life expectancy I'd want. Those are Jones' profiles.
More port flow and an aluminium head and I would have bumped the compression to at least 10.5 (or more). Say 280 cfm for the intake port and the spec might be 294/294/ 107 / 103. Overlap is 80 degrees. RPM is now north of 6200. Now we're talking. Idle vacuum is getting thin at 11" though but I worked with less with good results.

skinny z

I'm right in that camp for the 357 but I'm working more with seat to seat timing (280 in this case).

ULTM8Z

I'm running 1.6 rockers which helps a little on making the cam appear a bit bigger.

But, the nice thing is the high idle vacuum (~15 Hg) + the higher stall speed on the converter (reducing load on the engine in gear) makes for a much nicer brake pedal feel at idle. My old 212 cam in the 350 with the 1.6 rockers was putting down about 12 inHg at 650 rpm. You'd expect higher vacuum on a cam that small, but that may have been a function of that cam being 4 deg retarded as a result of the Votec timing chain (I had blindly ran the Vortec timing chain from the ZZ4 versus having degreed in the cam this time, which is where I discovered the built in retard). You could increase idle vacuum with a higher idle speed, but then the load against the converter went up too. I wasn't necessarily having to stand on the brake pedal before, but it did take a little more effort than on say a stock car.

Now, just light toe pressure is enough to hold the car stopped at a light.

skinny z

What did your intake centre line end up at?

89fast5oh

As we have found out in other threads, you and I have very similar 383s with similar spec cams with the same drive-ability expectations. It seems your and my car drive fantastic. That is what my goal was with my 383. To your first point, I have a 1989 Mustang with a 4.10 geared rear end, 5 speed trans, & 408W with a cam that is 244 duration with .0625" of lift. It is fuel injected and has a tune but sits there rattling your fillings out. It is "fun" to drive but not "nice" to drive. I would say it has 100 more HP than my 383, but again that is by design. I could have put a Comp 280XFI or similar cam and had a 500 hp 383, but then it would not have been nice to drive, for my expectations anyways. Don't second guess your choice!

Fast355

iTrader: (2)

Never much worried about the idle vacuum in either my Express or my G20 post hydroboost. Just is what it is. That being said the big bootlegger was about 13 in/hg @ 850. The smaller 218 makes 19 in/hg at 750 rpm. Smaller cam has sharper off-idle throttle response and makes 23 in/hg @ 2,500 rpm and about 24 in/hg @ 3,000 with no load on it. The exhaust note is fairly choppy at 750 rpm but the engine is dead smooth.

ULTM8Z

108

ULTM8Z

First oil change looked good. There are two oil changes specified during break in. I cut open the filter and it looked really clean. Also poured all the oil into one of those thin disposable aluminum baking pans, then poured most of it out slowly. Took a strong magnet and ran it around under the pan to see if I could see anything iron-based moving round. Nothing... overall it just looked really clean and free of anything that would indicate abnormal wear.

Next oil change is after 500 miles or 12 to 15 hours of run time. They want you to drive normally, but not getting up to maximum rated engine speed or extended periods of high load.

Sheesh...

Such an elaborate break in procedure. If you bought a Vortec 350 equipped truck back in the 90's, I don't recall GM putting this kind of procedure in place for new truck owners??

I guess they must be really conservative with these crate engines since they give the warranty with them, but they don't know how well the end user is going to install them and set them up.

Orr89RocZ

iTrader: (20)

Never was a fan on babying a new motor. You gotta set the rings and only way that happens is with cylinder pressure, so you should run it moderately hard. Initial heat cycles and oil changes is good, verify everything seems fine and no leaks etc. then obv need tune to be ok in order to be able to run it so the initial normal driving is time to establish proper fuel and timing. Then you work into wot for short bursts, working your way up in rpm to max. Race motors dont baby, and they get good ring seal. Not sure why they would recommend 500 softer miles

ULTM8Z

The first phase of break did involve some hard pulls...

They wanted 4-5 half-throttle off the line to 4000 rpm pulls. Then several more pulls at WOT.

But yeah, now the 2nd phase they want normal driving. I don't know, I'm just following the instructions to the T since it's a huge investment and I want to maintain the warranty.

After the 2nd phase, I change the oil again and then can use synthetic going forward.

skinny z

I've always been old school in that RPM's and loads are varied over time. One caveat was that a consistent load shouldn't be maintained over a prolonged period. I can guess the reasoning but still it seems to be all over the map as to what's right and what isn't. WOT, part throttle bursts, coasting with engine braking in effect, etc.

It'll be interesting to learn what the piston / ring manufacturer vs the machine shop has to say about this new shortblock break in that's in the works.

As for oil changes, I'll say the more the better. Cut the filter open and put the filtering media in a vise to squeeze out any crap or corruption that may be in there.
I keep dinosaur flavoured oil and not too cheap a filter on hand for that break in period.
Then full synthetic and premium filters for the rest of the engine life.

I don't blame you in the least for following the manufacturer's instructions. Some people have money to throw around. I certainly don't. I'll take the warranty and listen and obey.

skinny z

Is it that race motors have greater attention to the cylinder bore finish and different ring specs that allow them to thrash from the get go?
Researching my options for pistons and rings, it seems wide and varied. As for the bore finish, that too is something that for me is undefined. Plateau honing? In the days of my youth it was ridge reaming, dingle ball hone, then cast iron rings or you're off to the races.
And hoping you don't flush five gallons of fuel down the carb trying for the 1st fire of the new project.

Orr89RocZ

iTrader: (20)

In my opinion Rings are rings and need a certain finish depending on the materials. They dont know what they will be used in, race or street. There may be some slight differences in how quick they seat based in size as some race motors use thin rings but so do street ls motors lol

skinny z

When you mentioned "race engines" I'm thinking something outside of the ordinary. But then again, race and street have various levels of cross over so there's no telling what each spec might be.
In my case, I'm going from the old school 5/64ths cast iron ring pack to a somewhat less than old school 1/16th thick ring with a chrome faced top ring ( the shape of which I don't know at this time). It has to call for a different bore finish I would think and maybe one is better at the initial seal than the other. Can't say for sure.
Throw in a 1 mm or .8 mm ring and for me, all bets are off. I've no idea what that might entail but I'll wager that instantaneous seating is part of the plan.

Orr89RocZ

iTrader: (20)

Right they probably would require different hone finish perhaps. With todays machining tolerances, material technology and good efi tuning, modern motors get away with less ring thickness and tighter bearing clearances and watery thin oils lol. Old school thick rings just arent needed any more really with good piston design imo. But im no engine builder. I just see 200-300k mile ls motors with small rings go forever

skinny z

Watery thin oils is right. 0w20? Zero?
It all certainly has changed in the gap between between what I was doing and what I am doing. Hence the change in piston spec to what's available, (Speed Pro with a 5/64ths ring) to what I have to wait for ( Wiseco 1/16th ring). And that's fat by today's standards.
I'll wait thank you.

Fast355

iTrader: (2)

I don't baby an engine at all! Foot to the floor from day one. I have actually had a few vehicles I bought with under 10 miles on the odometer. I actually pulled out of the dealership and stuck my 2012 Titan to the floor twice within a mile and it had 6 miles on the odometer. Ran well enough some people called it the factory freak in my local Titan group that went to the track. I ran my 2014 Titan at the local drag strip with less than 400 miles on it, dealer plates and all.