Well we don’t claim to be the ‘hear all end all’ in 351c Stroker kits… but we have learned a lot through the school of hard knocks through the years with these kits and offer the info here along with the extra services included in our kits to eliminate the problems associated with them to help you make informed choices.
(Original content and some info paraphrased from various sources (including but not limited to Dan the Cleveland man))
In the past few years small block Ford stroker engines have been all the rage. Every machine shop and parts house advertises a few stroker kit selections, the most common is the 302 based 347 kits, but even 434 cubes are now available from the 351 Windsor and 400 Ford blocks! The Cleveland provides unique challenges which we will detail.
Some cranks are considered "Cleveland style" because they use the 351C main diameter, be aware some aftermarket "Cleveland style" cranks are not exact Cleveland replacement cranks. They are cranks meant to go in Ford Racing hybrid blocks (or other race block) which combines the 2.75" Cleveland mains with Windsor architecture. The Cleveland snout is different than the Windsor snout and some aftermarket "Cleveland style" cranks use the Windsor snout. Cleveland cranks have a "snout ring" ahead of the #1 main, to space the lower sprocket out to clear the journal. Windsor’s have a collar on the back of the lower timing sprocket to achieve this and the cranks are machined flat ahead of the journal. (See 351w crank left, 351c 400 w/collar right)
When using a "Cleveland style" crank in a production 351C iron block, a Ford Racing spacer (part number M-19009-A341C), is required and is discontinued but Hawks Racing makes a duplicate replacement we stock them and they are included in all our complete Balanced 351c Stroker Kits. There are true Cleveland spec aftermarket cranks but they are cu$tom order generally starting at $1000-2000 range.
The Cleveland #3 (thrust) main is narrower by approximately 0.009-0.015" compared to the 351w thrust. Some aftermarket cranks with 2.75" diameter mains use the narrower Cleveland thrust width which allows the use of Cleveland main bearings, but some 2.75" diameter cranks uses the 351W thrust width which requires a special thrust bearing to achieve acceptable thrust. Ask what the thrust is on the crankshaft for the kit you are considering… 351c or 351w. There are work-arounds for this, but they aren’t easy and require regrinding the crank so best to be informed. All TMD 351c kits have the correct thrust for the OEM 351w block. We also stock 351w thrust cranks for use in Ford Racing, World, Dart and our TMD Race Block.
Most aftermarket cranks use small block Chevy 2.1" diameter rod journals and GM 0.940" width rods. However, Ford Sportsman and some ‘Ford Journal’ 3.85" stroke cranks are set up for 2.311" 351w diameter/width 351W rods.
Virtually all 351c stroker cranks are designed for 6.200” minimum rod length, which is a problem considering the Cleveland’s 9.206” deck height vs the 351w taller 9.503” requires a 6.000” rod for most self stock pistons. Many Cleveland stroker kit suppliers have a disclaimer ‘*’ disclosing the fact that the OD of the counterweights will need clearanced to avoid the pin area or bottom of the pistons. This clearance needs to be ‘cam’ clearanced to preserve the cranks balance characteristics and will appear as flat spot compared to the counter weight radius and is just opposite the center line of the rod throw. This must be done prior to the final balance of your assembly. Be sure to ask if the crank in the kit you are considering is ‘clearanced’ for the rod/pistons in your combination. All TMD 351c stroker kits are pre-assembled and counter weights are ‘cam’ clearanced if required prior to balancing the assembly. (See below the before and after photos 408c cast steel crank. Notice the clearance notch to the block in the third photo, we have a template/tool for easy stroker clearance)
Canted valve Cleveland heads require uniquely positioned valve notches at the edges of the pistons. This is a challenge because the intake valve relief is cut down the outside edge of the piston about .250 to .300", leaving you little room for the ring package. The limiting factor for Cleveland stroker pistons is often the valve notch in the block and pistons. Cleveland blocks are usually notched at the tops of their bores for valve clearance/shrouding which can place a limit on the top ring placement (needs to be below the valve notch at TDC plus rod stretch). The depth of the notch varies but is generally about 0.25" down from the block deck. (See 408c 4340 crank with 1.200CH piston and 6.000” rods below, notice the valve notch just above the top ring land, also notice the piston contacts the crank at the pin and skit area prior to clearance)
This unique requirement and the additional stroke/rod length limit stroker Cleveland piston architecture. Many forged stroker Ford pistons are designed with compact ring packages so the oil ring does not intersect the piston pin on 1.165” and taller compression height pistons. The Cleveland package is such that it requires a 1.250” and taller compression height to ensure the oil ring does not intersect the oil ring. This unique requirement combined with the comparatively short deck height and 6.00” rod means all 408cid Cleveland kits will intersect the pin.
Many 351c stroker pistons also have improper skirt designs; they require modification or clearance to avoid the crankshaft bobweights on stroker applications. Our kits are all pre-assembled and the pistons are machined if required to ensure adequate clearance prior to balance. (Shown below before, during and after piston modification)
So now you are wondering… hmmm after all the ‘problems’ have been cleared up is this thing going to balance? That’s a great question and one the we don’t leave to chance, with the mods required to the 351c kit for a seamless install, we only offer our kits fully balanced with state of the art digital balance service. All 351c stroker kits 383, 393, 408, 418, 427 etc are all computer balanced to less the one (1) gram on both ends for a life time of service! Ask you local shop if you piece together a kit if they can offer that guaranteed service and printed results card verifying the quality of the balance job! Hope this guide helps you make a more informed buying choice for your Cleveland project! Any questions... we are here to help 951-369-0200. Search Ebay Motors Keywords "TMD Cleveland" for our 351 Cleveland Stroker Kits and other Cleveland parts! 951-369-0200 9-5 Pst M-F