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As some of you know CF member 89L98TPI (AKA Ron) has been getting down with one of my 383 SBC combo's for the past few years. Well, his daily driver 1989 C4 Corvette that makes 540HP N/A and runs 10.20's@130+mph on a 125 shot just wasn't enough for him..... I felt like we could push the little 383 into the 9's with more nitrous but we'd be stretching the engine harder than I wanted considering the parts in it and eventually it'd break. Ron had already upgraded his car to a 4L80 trans and had the D44 rear end swap with my old spool and IRS suspension, so I knew the drivetrain was going to be up to the task of going much faster (I went mid 8's in the 1/4 mile on that rear end/suspension).
We began talking about building a more capable engine last year. Ron wanted to stay GEN1 SBC and he wanted a good piece that would run into the 8's on nitrous reliably but still be street driven nearly daily..... We talked money (budget), after which I put together a plan for the new engine and he approved. He's been buying parts all year and we have been working all year to machine and assemble them. I just finished his new engine and Ron picked it up and took it home this weekend. He also gave me the green light to post a thread about it.....
Combo is as follows:
Short Block:
Dart SHP block (4.155 bore 9.020 deck)
Molnar forged 4340 crankshaft (4.0 stroke)
K1 Technologies billet 4340 connecting rods (5.850 length)
Diamond forged 2618 pistons (1.125 CH .043-1/16-3/16 rings 12.7 compression, gas ported, Line 2 Line skirt armor coated)
Trend H13 tool steel wrist pins (.200 wall)
Perfect Circle Firepower piston rings
King HP Rod and Main bearings
Kevko box style drag oil pan
Milodon oil pump
Top End/Induction:
Speier Racing Heads V2.70PF Profiler 23* cylinder heads (250cc INT Runner 65cc Chamber)
Manley stainless valves (2.125 INT and 1.60 EX)
Manley tool steel retainers/locks
PAC valve springs
Doug Lee fabricated sheet metal valve covers
Edelbrock 2970 Super Victor (Converted to EFI)
Nitrous - Dry direct port fogger by Fast Lane Nitrous Systems
Valve Train:
Jones Cam Designs custom mechanical roller (260/290ish@.050 - .750ish lift)
Morel roller lifters (.903 pressure fed)
Manley push rods (3/8 .135 wall)
LGM Racing and Development shaft mount rocker arms
Now this is a pretty serious engine. It will make around 700HP N/A. Camshaft is designed to stand about 350HP worth of nitrous. To make this kind of power and still street drive it, I choose to put it on E85. The fuel is cheap and widely available in his area but E85 requires a serious fuel system to support this kind of power. So he sumped the bottom of his stock fuel tank and used a Magnafuel external Fuel Pump and ran new -10AN fuel lines. Billet Atomizer injectors (160LB). Engine management will be from his current Holley HP EFI system.
This is also a budget build. Parts were carefully chosen to maximize performance/strength for the budget we had. In a couple of cases, I had lightly used/NOS (pistons, connecting rods & valve covers) or still perfectly functional but badly abused (oil pan) parts that I sold him or gave him. The intake manifold was also used but Ron sourced it from someone else. In all we were able to save about $1,500 with these parts. I love to take peoples money and turn it into their dream... as long as their dream is a racing engine. I am not going to give out the precise cost but it cost less than you would think for this kind of power and performance potential. Ron can chime in with his total cost for the engine if he wants...
Here are some pics of the machine work and engine assembly.
To start off we needed to put the block on our mill and clearance it for the rods....
The Dart SHP SBC block is kinda iffy fitting a 4" stoke crankshaft...... and sure enough we broke into the water jacket at the bottom of a cyl. This is something we knew could happen with this block/stroke/rod combo and luckily we were prepared to fill it. We mixed up and used a few lbs of Rokblock to fill the block to the bottom of the freeze plugs.
More work on the mill... this time I am modifying the intake manifold and plenum/TB adapter. This plenum/TB adapter is a prototype Accel piece that Ron acquired a few years ago and used on his 383.... He wanted to keep it for the new 434, so I did what was necessary to make it fit.
Few shots of me hand blending the intake manifold plenum area.
Finished intake manifold and plenum/TB adapter fit.
After this work, the Edelbrock 2970 manifold was sent to Fast Lane Nitrous Systems for the EFI conversion and a new fogger system. After we got it back we welded some brackets on the manifold to re-position and then re-plumb the nitrous solenoids to put them under the plenum/TB adapter. This was strictly a packaging detail that unfortunately I did not communicate well enough to Fast Lane. They did everything we asked and I was very happy with the work we got from Fast Lane. This thing is a piece of ART... and it supports BIG POWER.
The cyl heads are from Chad Speier at Speier Racing Heads.... Again these cyl heads are pure ART.
The valve train is spec'd out for power and reliability. Jones Cam Designs camshaft, Morel roller lifters, PAC valve springs, LGM rocker arms, Manley supplied the valves, tool steel retainers, locks and push rods.
LGM Racing and Development rocker geometry...... We ended up with a very tight pattern. .065" wide on the intake and .080" wide. This is with over .750" lift at the valve......
Shot of the Molnar Crank and K1 Technologies rods as the short block is assembled.
Pic of the Diamond pistons as we were Degreeing in the camshaft.
Assembled Long Block ready to be delivered... More ART with the fabricated Doug Lee valve covers that we had custom laser engraved.
I hope everybody here on CF enjoyed the post.
I know Ron is going going to enjoy his new engine. He has all winter to get a few other things done to the car itself that he has wanted to do for sometime now and then get the engine installed/car race ready in time for next season. I look forward to seeing it meet and exceed his goals just as the previous 383 did....
I would like to thank Ron for having us build him this engine. I enjoyed the development work that went into it, I thoroughly enjoyed the fabrication and machine work we performed and the coordination with other top shelf vendors that was required to complete a project of this magnitude. Myself, my Dad Johnny and my Brother Cliff at Magic Racing Engines were honored to build this engine for you.
Will
Last edited by rklessdriver; 10-15-2018 at 07:47 PM.
Reason: Technical Corrections
Thanks for posting-Nice build. Cool offset rockers.
How will it drive on the street with that large cam? Just asking.
Looking forward to see how it runs at the track.
Best Regards,
Steve
I know this cam seems big but it's really not a very big in a 434 inch engine. When you look at the cam in my 434 and even the one I had in the pump gas 427 before that for comparison, I specifically took this build down a couple notches for reliability and driveability on the street. The Holley HP engine management system Ron has will allow us to tailor the timing curve and idle speed to remove much of the part throttle and low speed surge from it.
To him I expect the new 434 won't drive much different than his 383 that he has been driving for the past couple years.
Track wise I expect it to run very low 10's maybe even break in the 9's on motor and high 8's on fairly small amount of nitrous.
I know this cam seems big but it's really not a very big in a 434 inch engine. When you look at the cam in my 434 and even the one I had in the pump gas 427 before that for comparison, I specifically took this build down a couple notches for reliability and driveability on the street. The Holley HP engine management system Ron has will allow us to tailor the timing curve and idle speed to remove much of the part throttle and low speed surge from it.
To him I expect the new 434 won't drive much different than his 383 that he has been driving for the past couple years.
Track wise I expect it to run very low 10's maybe even break in the 9's on motor and high 8's on fairly small amount of nitrous.
Will
Thanks for the information and taking the time to post.
Will knows the appreciation I have so no need for that here. I'll post some pictures of stuff mentioned but not pictured... 4L80 billet tail housing. With D44 in car Cbeam needed shortened and new holes drilled and driveshaft needed shortened as well.
4L80 with Circle D billet multi disc converter with Jake's Performance D1 trans brake/valve body.
AC delete panel powder coated black with Painless fuse block to power some goodies like Holley dash and gauges etc. Holley HP EFI ECU is mounted on panel inside car.
Rear bumper off and tank out. 383 pulled and parted out. Garage built...
Magnafuel 4303 with filters and Magnafuel regulator. Redhorse black braided hose and fittings. -10 fed -8 return.
Had the stock tank sumped with -10 fitting welded on bottom and -8 on top next to sending unit. Only using sending unit for float because the stock Digi dash in still in car and working!
She's home!! Junk block behind being used for motor plate mock up. Test fitting electric water pump and misc fittings for coolant system.
This intake is pure ART!$! Those injectors ain't to bad themselves...
Cool stuff! I also have that tail housing (converting to a 4L80e).
Did you always run it with a trans brake?
Regards,
Steve
I never got a chance to use it with the 383. I hooked it up, tested it and had flyback voltage from brake to ECU. I needed a diode to stop it .Never got a chance to hook it up before we tore car apart.
Thanks for the pictures, that is a beast and should make any Corvette happy.
Do the Vertical Gas Ports really help these motors seal their piston rings better? Is there a limit to ho much compression they can handle? I had never seen them before, I must be out of touch or just getting old....
10-15-2018, 04:42 PM
89L98TPI's new 434 SBC
