Quote:
Originally Posted by Jay S
Your short on info to discuss how well the cam will work. Things like compression, carb and induction, transmission, stall, gears, and what car it is going in. Bulter’s I assume had that info when they suggested that cam.
The combo is apparently pretty mild if that 114 LSA version of the 423 is the cam Bulter’s recommended. Probably the KRE D ports are likely a good fit. I think you would be happier with that cam on a 112 LSA, it really needs more exhaust duration or seat timing for the LSA to be spread out to 114. I know I would be happier anyway.
Your probably thinking 65 cc KRE d port, but I would opt for the 75 cc KRE d ports if your keeping the cam small. But since I don’t know what the compression will be, I admit it is kind of a guess. The smaller the cam, the less gains you will see adding more compression.
You will loose about 40 lbs switching to aluminum heads.
I have been noticing some more reproduction round port RA manifolds showing up on E bay. If you don’t have the RA manifolds, and can find some round ports RA’s that fit your chassis, you could save some money and make more power going with round ports. I think a 72 cc E head with bathtub chambers is $2600 to $2700. The KRE’s and most of the cnc chamber E heads are well above 3K. All the aftermarket head options need new head bolts, the iron head bolts are to short. SM round ports are about $2150 assembled? But you need shop to look at them before you use them, really need that on any of the options. It often takes $300 to get SM head ready to use, the valve job isn’t very good.. So your really not saving much. The head casting are made from good material, as good as any. But… JMHO, the valves springs, valves, and valve guides SM uses are made from inferior junk that won’t last over the long haul. Save now, pay later kind of deal. I admit though I have a bad bias when it comes to SM..I can’t stand them…lol
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Thanks Jay - So here is what I am working with:
1978 Trans Am with no knowledge of the work that had been done previously. "557" casting 400ci. TH400 with unknow stall torque converter. I am planning on converting over to a TKX at some point but will initially run this engine with the TH400. Rear end now has 3.42 with an Eaton Tru-Trac that I put in it. Came with a beat up 2.55 hidden inside of a 3.23 housing.
I have the engine torn down and see that the work done appears to have been fairly recent (25k miles?) based upon the cleanliness of it and the prominent crosshatch in the cylinder bores. It has been bored out 0.030 over. You have the detail on the "62" heads and their current condition. The crank is an Armasteel 9773383 out of a 64-65 389ci. and has been ground 0.010 on both the rod and main journals. The intake manifold is a 481733 casting out of a 71 400ci. I plan on reusing this manifold and running a Holley Sniper EFI on it. Currently has headers of unknow origin that will be replaced with the aforementioned RARE RA D-ports that should arrive in a couple of days.
My intention was to build a 400hp engine really just for fun. It wont be raced. Maybe a car show or two and I want to be able to run on pump gas. The cam recommendation from Butler was based upon being asked if I wanted the idle "smooth, mild or rough"...I said "mild" hence the 114 LSA. For what it is worth, I ran the cam past Jeff Kaufman and he thought it would be a great fit for the aluminum KRE 74cc d-ports and suggested a 1.65:1 rocker arm. As far as compression goes, I am assuming I am going to be right about 9.75:1.
Hope this info helps and if I can provide anything else please let me know. Any input is appreciated. Thanks--Lee