Knocking 1989 7.3 idi. Help!

[riotwarrior]

I will time by ear over the phone for 50 bucks...

 

[pelky350]

When I timed by ear I was judging by how fast it started, starting from a point of I knew it was retarded and before the powerstroke rattle. Then had shop time it I was at 7'

 

[Beefguy]

I'm on R&D IDI performance website what is the difference in IP's RD2-80-RD2-110 and RD4-150 RD4-180?

 

[Macrobb]

I'm on R&D IDI performance website what is the difference in IP's RD2-80-RD2-110 and RD4-150 RD4-180?

Fueling capibility.
He rates his pumps in terms of number of CCs(per 1,000 strokes/injection cycles) at 2800 RPM(max power for an IDI).

Generally speaking:
A NA motor? Go with a 80CC pump. You won't need even that much to fuel it. HP wise, you won't get more than 125 at the wheels on a dyno.

Factory turbo motor or "stock" turbo kit - a stock 7.3 with Banks, Hypermax, ATS or Factory Ford turbo: Go with a 90 or 110 CC pump.
The 110CC pump will 'max out' the amount of air you can get from any of those turbos, but it's a very solid combination.
I don't have a 90CC pump to see exactly how much is 'lost' comparatively with the same setup.
Most turned-up 'stock' turbo setups with 'stock-ish' pumps make in the 180-200 HP at the wheels range.
A 110CC pump and said turbo will make a consistent 240-250 at the wheels - it's all the turbo can flow.

Anything bigger than 110CC pump is going to be for 'extreme modded' IDIs - this means headstuds(to keep the head gaskets from blowing), custom turbo(something bigger than any 'stock' turbo), and probably internal improvements as well, like a main bearing girdle and connecting rods, depending on the HP you are going for.
This is when you are looking at big $ and big HP numbers in the 300-450 range at the wheels. And, to my knowledge, nobody has done over 450 at the wheels with a modern IDI(There's a legend out there of a Hypermax motor making 1,000 at the wheels back in the 80s, but that wasn't reliable and was totally custom).

 

[Beefguy]

Perfect thanks

 

[riotwarrior]

Girdle for mains not likely needed ...beefy bottom ends...for most anything except serious competition engine IMHO