Building a 454, suggestions welcome!
- Thread starter Huffy67
- Start date
I would stay with the bigger cam with your 454 and 88 heads. The converter should work fine. The Cam you have picked out is close to what is in my Big Block, it works well but I don't think it will move enough air for your heads.
If you have open chambers then yes you will need domed pistons. Did it have forged pistons?
If you have open chambers then yes you will need domed pistons. Did it have forged pistons?
Make sure of your bore before you order pistons... Typically a forged piston requires more cylinder wall clearance than a cast/hyper piston.
Let me add to my back story... The old engine melted between 3 & 5, and also between 5 & 7. Ruined the head so I found another, thought the block was ok, machine shop took .045" off the deck!!!! I decided to find another block. Also a couple Pistons tried melting a little on the sides. Idk if it all started as a bad head gasket or what but with that blower on there it got nasty in a hurry!! Anyways, the block I found is supposed to be all stock and has been cleaned and magnafluxed.
I do agree with you about cylinder clearance though, I remember when I built it last time they had to hone it out for proper clearance for my forged Pistons and plasma moly rings.
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I talked to Comp and they spec'd me the 11-235-3. Doesn't seem right to me, especially since it doesn't even offer it as one of the 20 options for me on cam quest 6. I guess I'll get the 11-243-4 that you suggest and hope for the best. Only thing I'm worried about really is the stall, not too big of a deal though, a convertor for a 4l80 is pennies compared to an Allison triple disk.
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Im still in the process of finishing my BBC. .070 over bore, 4.25" stroker crank, roller motor, dominator 1250, 11:1 cr, 1.88/2.16 valves in some worked over iron oval port heads, etc
Nice!! You should have a lot more ponies than me, I just want mine to run!! It's been down for a couple years and I'm finally getting around to messing with it. I'd like to have more power, who wouldn't, but I should have atleast 400 and that'll be fine for what I'm doing with it.
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Hi Huffy! So a few years ago I built a 79 Camaro with a 350 H.O. engine. I used that same Comp Cam, the 268H, and I really liked it. I ran an Edelbrock RPM intake (not AirGap) and an Edelbrock carb, and the peak RPM curves of all 3 matched up really well. Break in was very easy, throttle response was fantastic, and the idle sounded awesome.
Having said that, I wish I would have gone one step up. I went with a stock-ish 1800 stall torque converter, which turned into a 2100 stall converter in my heavy car. Even though it still mated perfectly with the cam, it felt a little reserved after the torque converter upgrade.
If you have any plans at all, I would go one step up with the cam to the....280H? It is still mild, very streetable, great idle, and won't kill your gas mileage. That way you have a little more play with your torque converter, and down the road I would rather upgrade that than my cam again.
Going above the "recommended" stall speed with your cam, especially by such a small amount, won't hurt anything whatsoever, it just means that the torque and HP curves aren't perfectly synced. What this will do though is somewhat future proof your car, because any little performance changes you do down the road will be getting closer to the sweet spot on the cam one step higher, but one step farther away from the sweet spot of the 268H.
Edit: Also, 10.1:1 compression is a good compromise IMO. A lot of the engines from that era were 9.5:1, my engine had 11.5:1 and if I dared run even midgrade I could hear the engine knocking. This also meant that if I ever wanted to turbo or supercharge it, I automatically had to do new heads, or risk being at 14:1 or worse and blowing the engine up. Stick with what you've got.
Having said that, I wish I would have gone one step up. I went with a stock-ish 1800 stall torque converter, which turned into a 2100 stall converter in my heavy car. Even though it still mated perfectly with the cam, it felt a little reserved after the torque converter upgrade.
If you have any plans at all, I would go one step up with the cam to the....280H? It is still mild, very streetable, great idle, and won't kill your gas mileage. That way you have a little more play with your torque converter, and down the road I would rather upgrade that than my cam again.
Going above the "recommended" stall speed with your cam, especially by such a small amount, won't hurt anything whatsoever, it just means that the torque and HP curves aren't perfectly synced. What this will do though is somewhat future proof your car, because any little performance changes you do down the road will be getting closer to the sweet spot on the cam one step higher, but one step farther away from the sweet spot of the 268H.
Edit: Also, 10.1:1 compression is a good compromise IMO. A lot of the engines from that era were 9.5:1, my engine had 11.5:1 and if I dared run even midgrade I could hear the engine knocking. This also meant that if I ever wanted to turbo or supercharge it, I automatically had to do new heads, or risk being at 14:1 or worse and blowing the engine up. Stick with what you've got.
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Well so far I have ordered an Edelbrock RPM Air Gap intake, Proform HEI distributer, Comp Cam K kit, 270H grind. Have the bare block, crank, rods, and heads ready to go to the machine shop. Also picked up an ARP complete engine bolt kit, and complete serpentine setup from an early 90's truck. Can't wait to get everything to the machine shop so I know what size pistons and bearings to get so I can order my rebuild kit.
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Finally got all my machine work done a month or so ago. Just gotta find the time to assemble it. The block ended up already being 30 over and wouldn't clean up so now it's 60 over. Also had to be line bored. So it'll be a 468 with all the parts I have acquired that are listed in my previous post. Shooting for 10.1 compression.
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