hey guys. So im looking at upgrading my 401s Cam. The engine is fresh built and hasn't been put in the car as yet or broken in. Been reading a bit across the internet. Have asked my builder for advice as well and as he gets back i thought I would ask here and see what you all think. So a bit of basic info. Car: 1949 Hudson Custom Weight: Stock curb side was about 1700kg/3730lbs Gears: 3.50 Tire Size: 28inch Trans: 700R4 Converter: 1650 but realize i may need to upgrade. Engine: 1965 Buick 401 or as most affectionately know them by a "Nailhead" Usage: Highway & city. I live small town & highway drive to city a few times a week. Also weekend cruiser. And the work done by Dual Quad Dave of HAMB reads as: 1965 Buick 401 core Bored .060 over to 413 Decked .020 to compensate for modern head gaskets New cast pistons New Hastings moly rings Balanced Rods resized w/ ARP rod bolts Crank turned .010/.010 and polished Oil galley plugs converted to screw in New Melling oil pump New Melling cam/lifters New Melling valve springs Heads rebuilt w/ new valves, new iron guides, cut for Teflon oil seals, milled .010 New freeze plugs Updated to modern silicon front/rear oil seals Good used timing cover New timing chain New water pump Included pulleys& alt/ps brackets. Included stock exhaust manifolds Stock Power steering pump. New Powermaster 1wire alt. Stage 1 porting. Polished chambers. cleaned up castings. Adjustable pushrods. Stock 4brl Intake- swapped out to Eelco 2x4 Media blast & prime. think thats about it. no doubt i missed stuff. Dave who built up the donk was great. Gave lots of performance options and stages. Answered all my questions well and gave options. On top i have Eelco 2x4 intake with 2 650s. Pertronix ignition. Anyway. As i do other work on the car i have been kinda regretting not getting the cam done when i got the darn thing built. Better half keeps asking "is it going be loud and lumpy?" I had been thinking Thumpr 91-600-5 or TA Performance TA-25 ideas and suggestions? Thanks Alex
Very nice! Even the stock cam is on the lumpy side with 207* duration at 0.050", 114* lobe separation. The dual quad cam has 109* separation. The 1650 converter stall is low compared to even a stock Buick. It may not even like the stock cam, more cam will need higher stall. Those cast pistons are likely still 0.020" below the deck after milling, you could use a steel shim gasket for more compression. Most Buick guys don't put the valve seals on the exhausts. They could use some extra oil. You have to check piston-valve clearance on these, even a mild cam might be tight. The TA25 is a slight upgrade over stock for your use, but I'd suggest test driving your present combo first. It should still have a slight lope, have good low end and 'might' be okay with the 1650 converter. Here are the specs for the Clevite stock cam. Melling is likely almost the same. Engine Parts Camshaft (Hydraulic) Item#: CEP2291606 Price: $ 114.00 Attributes: Attributes: Camshaft (Hydraulic) Cam Lift (Intake): 0.269'' Cam Lift (Exhaust): 0.269'' Valve Lift (Intake): 0.430'' Valve Lift (Exhaust): 0.430'' Degrees Overlap: 74 Deg Advertised Duration (Intake): 295 Deg Advertised Duration (Exhaust): 302 Deg Duration at .050'' Lobe Lift (Intake): 207 Deg Duration at .050'' Lobe Lift (Exhaust): 207 Deg Cam Timing at .050'' Lobe Lift (Intake Open): 9 Deg After Top Center Cam Timing at .050'' Lobe Lift (Exhaust Open): 39 Deg Before Bottom Center Cam Timing at .050'' Lobe Lift (Intake Close): 36 Deg After Bottom Center Cam Timing at .050'' Lobe Lift (Exhaust Close): 12 Deg Before Top Center Valve Lash (Intake): Hydraulic Valve Lash (Exhaust): Hydraulic Lobe Centerline (Intake): 112 Deg Lobe Centerline (Exhaust): 116 Deg
With cams that small, I'd go with as tightest of an LSA of your choices. Even with a potentially raspier idle, it will wake up stronger on the bottom end.
See my other cam post for additional cam details. If you've got a stock cam and you except it to be lumpy, you will be disappointed. The Thumpr will be lumpy and perform very well. It will, along with any other "performance" cam require a different converter - 1650rpms is very LOW for any thing but a stock replacement, IMHO. If you want something lumpy the Thumpr will work great - but it isn't as easy to tune around as a mild offering like the TA-20 or TA-25.