Hey Guys,
I would like to get a 400/451 Stroker built
# 500hp / 500tq at minimum, dont need any more.
# 91+ Octane Pump Gas
# 10K budget for parts, if possible including labor
# Hydraulic Roller Cam for reliability with current day oils and no break in issues
# All New Parts as much as possible (Except Block Of course)
# As little Chinese parts as possible
# No constant adjustment required
# Around 10:1 compression
The car will be for
# Street Weekend Fun Use Only. (maybe 2000 miles per year)
# Manual Transmission will be used
Why 451? And Not 440?
# Revs higher & faster
# Lower Piston Speed
Any complete recipes or ideas? I dont want to deal with mismatched parts
My first 451 (around 1990) used a 440 crank with the mains and counterweights machined down to fit the 400 block. Reconditioned 440 LY rods with ARP rod bolts, and custom Ross pistons (dished 11:1 with the 64 cc heads). At the time, used early prouction B1 B/S heads (64cc and undrilled for accessories.) and a M1 intake.
Ultradyne 251/251 @ 0.050" duration, 0.620 lift solid roller. Most likely around 575 HP?
Now the price of stroker kits with 4340 cranks and rods are so affordable, it is hard to argue going the old used parts route?
The 440 source "400 >> 512" kit with the -24cc dished pistons will give about 10.4:1 compression with trick flow 78 cc heads.
These stroker kits are good, but not perfect. If using the stock style crank bushing for the 4-speed manual trans, the bushing hole in the stroker crank shaft may need to be reamed to the correct diameter. You could also use a newer style roller pilot bushing that mounts in the recess where a torque converter hub would go?
The 4.25" stroker crank uses the smaller 2.20" connecting rod bearings, so clearance in the block is as good or better than using the 4.15" stroker crank with the stock size bearings. Usually just the oil pickup boss needs to be clearanced. You (or the shop) will have to file-fit the piston rings. Sometimes the rod pin bushings are tight and need a quick hone. The pre-balanced kits should not need any balance work for this application (should be within 1-2 grams)
The stroker crank can make windage tray, oil pan, and oil pickup selection more difficult. You did not mention the body style, but this is "for B-bodies only", so for street cars, I like using the reproduction 6-qt Hemi oil pan as it sits at the same level as the K-member. The 440 source stroker windage tray is too deep to fit stock type oil pans, but will fit a deeper race oil pan. I also like using the Jegs Molded windage tray/oil pan gasket
http://www.jegs.com/i/JEGS-Performance-Products/555/502001/10002/-1
, bit they don't exactly fit a 4.25" stroker crank. On my 440 >> 512 engine, I made tray/gasket fit by heating and re-shaping it, but I think a better solution is just get the 440 source 1/4" main cap girdle. It comes with all the hardware you will be upgrading anyway. This now brings up he fitment of the oil pickup tube?
I don't know if the matching pickup tube to the oil pan clears the main girdle? Maybe someone will comment.
All my engines have been modified to use the 1/2" pickup tube, and I think I had to heat and reshape the tubes that came with the oil pans, or I just made entire new pickups. There is a better selection of 3/8" tube pickups, but I don't know how well they fit?
I would start the build with some Trick Flow 240 heads. These are really good out-of-the-box, so they don't need extra work or valve spring changes (if you order the correct spring package with the heads.) I had my head shop inspect the heads and flow bench them and they said they were good to bolt on, and flowed as advertised. The 440 source and Edelbrock heads seem to flow less than advertised out of the box, and you the valve springs they come with won't work with a hydraulic roller cam.
The Low Deck 400 block fits great, but limits your selection of Intake Manifolds. For a mild engine the Edelbrock Performer RPM is a good choice. Trick Flow had a single plane intake now for the 400 block too if you decide to go 600+ HP. I like electric choke on carbs for a true street car, so last carb I used was a Holley ultra avenger 770 on the 440 >> 512 (really only 505" with a 0.030" overbore) before changing to EFI. My original 451 mentined above ran a Holley HP 1,000 CFM carb and was fine if you held the throttle about a minute till it warmed up. I have been converting more of my stuff to EFI, so I'm not up on the latest carb stuff?
Additional costs for the aftermatket heads include, Harlan Sharp rocker arms (I'm using 1.6:1 ratio), rocker arm hold down kit, and ARP head bolts, custom length pushrods. Don't try to cut costs in the valve train, cheap rocker arms are not worth the trouble and you will just end up buying the good stuff later.
The hydraulic roller Trick Flow used in their 620 HP build would be a good choice.
https://static.trickflow.com/global/images/chartsguides/t/tfs-k616-620-576.pdf
243/
[email protected]" duration, 0.600"/0.600" lift. The cam looks sort of big, but in a 512" engine should be fairly tame.
I'm not really sold on the Hydraulic roller cams. I have a mild Comp Hydraulic roller, XR286HR-10 in the Coronets 440 >> 512 (505) and I thought it would be quieter, but I think with all the roller valve train, and roller thrust button, and lifters, it still sounds like a sewing machine. That cam is 236/
[email protected]" duration and makes great torque. That engine is using the older 84cc 440 source stealth heads and 17cc dished pistons, with block milled so compression is about 10.3:1, and I think a slightly larger cam would make running on pump gas easier. I think I may have hear it ping once in awhile on really hot days?
My next build (Jensen Interceptor with the Trick flow heads mentioned above) is getting a nylon thrust button but solid lifter roller cam) to see if it is quieter? Additional cost of going roller cam is the bronze oil pump drive gear. I use the Melling HV oil pump from 440 source, and I have the stainless ARP 12-point bolts (for looks), but make sure the oil pump bolts are correct length. The HV pump needs longer bolts, but the longer bolts are often too long and bottom out, needing to be shortened maybe 1/4"?
