Tbi intake

Quote:

Originally Posted by myburb

I have a 94 454 tbi on a 6395 pcm. It had a head gasket problem so while repairing that I put in a larger cam (500 lift), mild ported and blended the stock heads. The question is what intake to use. I am doing this with parts I have in the shop. I have a 93 gm intake with ports opened quite a bit. A 94 gm intake which seems to have some odd holes in the (probably egr) throttle bores and a edelbrock victor air gap with a tbi adapter. My biggest concern is icing. I am installing an external engine oil cooler so could build shroud to route intake through in winter don't really like the idea of hot water through the intake in the summer. So what do you think? Any icing horror stories?

I worked @ GM and was able to ask many ? from the ones that know. I did ask about the TBI intake and why the adapter or "baby foot" is on the BBC. They had done allot of dyno testing after the truck released it for the Marine use. They found no power gain to speak of even with aftermarket TBI intakes. Eldabrock people explained to me they to had no real luck with any design and this is why it remains as is. The throttle blade tend to steer the fuel and run rear cyl richer than front. In the bead cat converter cal, there is fuel added to COOL the bead converter at WOT. The pup converter has a hole in the middle if it so when the bead fails, most of the beads might exit the rear pup conv.
The Marine personal fabricated some adapters up to slide the TBI rear to front on the dyno. The Marine adapter was re;eased with best power as is. Not really much diff. I suggest you raise the TBI up an inch or two.
(Why TBI and not port fuel? I asked. $$$$$$ 600-800 more for port at the time back then for each engine.)

Air cleaner I would use the bottom Big block, add another snorkel to the frt of the core support and use the 85 small block LARGE tall top (If you have a single hold down air cleaner base. Use the Large A/C filter. This has the highest flow at 750+ CFM and with two snorkels it pulls cold air.
Winter, black off one snorkel and pull air from under hood. If your area is cold and High Humidity, like Mich, use the hot H2o in the baby foot. Otherwise is the humidity is low and cold you don't have much to worry about with TB Icing as I have seen on the Climatic wind tunnel testings and real world.

My big block with a carb had the large top air cleaner with 2 inlets. Winter, I didn't change it but it had little use also. Our calibration trucks I ran one BBC 8.1 with a direct tube to the filter, then to the MAF. No icing was noted or power loss in Mi all winter. My BBC now is EFI with 58mm twin TB and MAF. No heated TB or base. But in southern TN at 700 feet alt. Hi humidity.

Back cutting the intake valves helps low lift flow and power. I use it on all of my own.

The TBI is a small port to keep the fuel from falling out of suspension in the runner. Personally, I opted for the oval port iron heads bowls opened, back cut intake 3 seat angle and port matched. Use Port or 8 injectors. Better fuel distribution. Use a Denso Heated O2. A/C fail in the new or last few year BBC from heat. Denso take 100 deg C more temp before failure and last longer.

If you run a Mark 5 block use the Memcal and knock sensor. If you have a Mark 4, you are restricted to an external knock module and must use an ECM that is set up for this. Like an old 165 MAF or you may convert to a Aussie 808 cal with MAP for the knock system.