3.80" stroke 383???

H

hquick

Member
Hi All,
I'm currently picing together parts to build a 383 for my 98 K1500 Suburban.
I can't seem to find much/any info regarding the use of a 3.80" stroke crank.
I picked up a GMPP forged crank for $370 (rare as hens teeth and about $2100 normally here in Australia)...so I couldn't pass it up.
I'm looking at going with Eagle 6.0" H-beam rods and JE forged pistons.
I'll be using the stock '062' Vortec heads (for now) along with a modified Holley 'Vortec' intake and Whipple blower.
I also have a ZZ4 cam a friend in Canada gave me.
Can anyone shed some light/ideas on my planned build?
Thanks

Howard
 
heres you basic factory built 383sbc performance engine
12498772.gif

12498772 - GM Performance ZZ383, 383cid/425hp Performance Crate Engine
Detailed Description

The all new ZZ383 offers Big Block performance with a Small Block price tag. GMPP starts with the legendary Fast Burn cylinder heads and 383cid, to offer an incredible 460 ft. lbs. of torque @ 4500 rpm with a smooth, linier delivery.

The combination of a 3.800 steel crank and a stout .509/.528 lift hydraulic roller camshaft produces 425hp @ 5400 rpm, making the ZZ383 the benchmark by which all other 383cid small blocks will be measured. GMs testing was completed using a GM single-plane intake manifold, a 750cfm Demon mechanical secondary carb, and 1-3/4 primary x 33 length headers with a 4 collector. A dual-plane intake manifold can be used, but will affect overall peak performance numbers by 15-20 HP.

TECH SPECS: *Horsepower: 425 @ 5400 *Torque: 460 @ 4500 *Max. Recommended RPM: 6000 *Compression Ratio: 9.6:1 *Crankshaft: Forged Steel *Connecting Rods: 10108688 PM Rods. *Camshaft 12370846 (hydraulic roller): -Gross Lift (.509 I / .528 E.) -Duration @ .050 (222 I / 230 E). *Cylinder Heads: 12464298 aluminum 62cc. combustion chambers. *Rockers: 1.5:1 Roller Rocker *Four bolt main block *Powdered Metal Connecting Rods *8 Balancer *GM aluminum single-plane intake manifold.

http://paceperformance.com/index.asp?Pa ... odID=73193
383_425.gif


keep in mind that the quick formula, for finding displacement on a V8 is.... bore x bore x stroke x 8 x .7854= displacement

the 3.80" stroke cranks were designed to allow you to build a (383) displacement SBC without boring the block .030 oversize, it was based mostly on the concept of allowing the factory 4.00" bore blocks to be used with the longer stroke and cash in on the popularity of the 383 sbc, without the need to cut the main journals on a 400 crank or use of the 400sbc shorter rods. this allows the factory to build a 383 with the standard 350 blocks and connecting rods and only special pistons are required
standard bore pistons or pistons designed for the more common 3.75" stroke cranks can be used if you get the piston matching your blocks bore size because most factory blocks that have not been decked measure about 9.023" tall
naturally you need to measure clearances but the extra .005 in stroke is basically meaningless as it means the standard 383 piston will ride .0025 higher up the bore wall, and most pistons don,t reach zero deck height

http://www.kb-silvolite.com/test/kb_car ... RodLen=5.7

read thru these links and sub-links

viewtopic.php?f=44&t=38

http://garage.grumpysperformance.com/index.php?threads/383-build-for-a-friend.14273/

viewtopic.php?f=53&t=726

viewtopic.php?f=51&t=125

viewtopic.php?f=69&t=2145
 
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Hi,
Thanks very much for the reply and the reading material....I'm working my way through it
My main issue is 6.0" rods or 5.7" rods? I have been told either/or by alot of people.
From your experience, what would be your personal preference?

I'm aware of the HT383 and the ZZ383...and would love to be able to just ship one over to here but, without sounding like a tightass, I really can't afford it.
By the time it landed here....I would most likely be out of pocket in excess of $10K.
I want this motor to be strong and reliable....but with plenty of power to get the Suburban up and running. Don't know about breaking traction at 60mph (that would be fun...Lol!).
So far I have installed the Mercruiser Marine intake, Whipple SC, Walbro 255 fuel pump, 4L80E trans, Hydroboost breaking system and I have a 14bolt SF diff sitting in the shed ready to go in and I tune it myself using EFILive and a Moates Roadrunner.
There's zero support or info in this country for these vehicles so I appreciate people such as yourself setting up these forums and sharing your vast knowledge...thankyou.

Howard
 
I build most of my 383 engines with the 6" connecting rods and internally balanced crank assemblies, but the 5.7" rod engines seem to run just as well in street cars, the minor theoretical advantage of the longer rods is in the longer dwell time at TDC , that at least in theory provides a bit more effective cylinder burn and pressure curve and the lower thrust angle on the cylinder walls that generates an insignificantly lower drag, and the greater room for the counterweights on the crank to by-pass the piston skirts during rotation, allowing for larger counter weights which in theory results in less crank stress. in theory the 6" rods are a bit more efficient,in practice there is little difference.

viewtopic.php?f=53&t=510

viewtopic.php?f=53&t=1168

viewtopic.php?f=53&t=141

viewtopic.php?f=53&t=1795

viewtopic.php?f=53&t=1017

viewtopic.php?f=53&t=341
 
Thanks again for more great info.
I understand it would have been preferrable to buy a complete rotating assembly from one source, but this crank popped up so I decided to go that route.
I have alot of friends in the US...who regularly ship me parts so getting components isn't too difficult (apart from the cost of shipping).
Do you think the ZZ4 crank will suffice?
I will change to Comp 26918-16 beehive springs, Comp 787-16 retainers...and not sure if I should go with the stock locks or just get a set of the Comp 648's.
I am already in the process of removing the stock rocker studs and installing the ARP screw in studs.
I'll definitely go with the 7/16 rod bolts...upgraded.
I have been quoted $350 for the Eagle 6" rods and $685 for JE pistons, rings and pins...which I'll most likely go with.

Here's a couple of pic's of my current setup...and a couple with the new intake/intrcooler setup I'm working on.

Mercruiser setup...


Thanks again for taking the time

Howard
 
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you might want to read thru these threads

/viewtopic.php?f=51&t=976&p=1706&hilit=+epoxy#p1706

viewtopic.php?f=51&t=588&p=4946&hilit=sonic#p4946

viewtopic.php?f=73&t=1424&p=3149&hilit=sonic#p3149

viewtopic.php?f=51&t=125

theres only one reason to fill or partly fill the the blocks coolant passages, and thats to add support to the cylinder walls and shorten the un-supported length of the cylinder wall in the area the coolant passages, in the block, that are adjacent too those coolant passages.
this is basically a repair on a potential problem of cylinder walls, flexing under high stress and reducing ring seal,cylinder walls that have been bored too thin for complete ring support under high stress conditions, and not necessary on most aftermarket blocks,with thier far thicker castings LIKE DART BLOCKS,where the cylinder walls remain at least .200 thick after boring, stock blocks with their far thinner block castings frequently benefit from the increased support, in the coolant passages
Filling the block up to the level of the lower edge of the freeze plugs has almost no effect on the engine cooling and adds a bit of cylinder wall rigidity, any more than that level of fill in the coolant passages tends to reduce the engines cooling efficiency, and should NOT be done in my opinion on a street driven car.
 
OK....last night I decided to 'gasket match' the exhaust ports on my 'spare' Vortec heads.
 
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It probably can be welded but on cast iron its expensive and in an exhaust port you can,t get away with brazing or soldering
it may be cheaper to buy a replacement head, thats one reason I constantly stress the fact that aluminum heads are far lighter in weight and MUCH MUCH! CHEAPER AND EASIER to REPAIR

you are not the first guy to screw up a set of very thin factory cast heads,castings so don,t think you did something terribly wrong, and yes its part of the learning curve. aftermarket heads frequently have heavier castings , but once again Id point out that ALUMINUM, while more expensive initially is frequently less expensive in the long run, and buying the best heads you can possibly afford , consistent with your budget is almost always a sound move.
BTW you only SMOOTH out the floor of exhaust ports on vortecs as grinding any material from that portion of the ports counter productive, in fact leaving a slight ledge, as the exhaust exits the head port and enters the header primary, tends to help reduce reversion pulse strenght, helping scavenging

viewtopic.php?f=52&t=462&st=0&sk=t&sd=a

viewtopic.php?f=52&t=401&p=6078&hilit=vortecs#p6078
 
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