Topic: Carter X Fuel Pump

[1970 Snake]

Thanks Royce, I did all the oil gallery mods, top end restrictor and correct down positioning of the rocker shaft holes. I did all the assembly and measured all bearing clearances and all within spec. Yes cold start I am getting your defined readings with 10-30 comp cams break-in oil with 80 psi at 2K rpm. Run temp idle 20 psi, 2500 rpm 45 psi, 4000 rpm 65 psi. After doing a bunch of reading online its seems pretty standard to have 10-15 psi or less at idle on a run temp engine. As you can see from my engine test run stand pic I am also running an engine oil cooler setup (cooler bypassed) which also has a relief in it, I am assuming that will not have an impact on engine oil pressures.

[RoyceP]

That's mighty thin oil. Might make better pressure with a more typical oil for FE's like Valvoline Racing 20W-50.

Oil cooler should make no difference in pressure.

Everything that you mention sounds normal with 10W-30 on a hot day.

Thanks Royce, I did all the oil gallery mods, top end restrictor and correct down positioning of the rocker shaft holes. I did all the assembly and measured all bearing clearances and all within spec. Yes cold start I am getting your defined readings with 10-30 comp cams break-in oil with 80 psi at 2K rpm. Run temp idle 20 psi, 2500 rpm 45 psi, 4000 rpm 65 psi. After doing a bunch of reading online its seems pretty standard to have 10-15 psi or less at idle on a run temp engine. As you can see from my engine test run stand pic I am also running an engine oil cooler setup (cooler bypassed) which also has a relief in it, I am assuming that will not have an impact on engine oil pressures.

[1970 Snake]

Thanks, yes was planning on running 20-50 later, thinking possibly Amsoil Z-rod synthetic after 1 or 2K on the engine, just wanted the 10-30 for break-in and initial easy running.

[RoyceP]

If it's a flat tappet cam I would drain the oil after the 20 minute lifter break in. Install Amsoil if you like, it won't hurt anything nor will it justify its higher price.

Thanks, yes was planning on running 20-50 later, thinking possibly Amsoil Z-rod synthetic after 1 or 2K on the engine, just wanted the 10-30 for break-in and initial easy running.

[1970 Snake]

Yes definitely changing the oil and filter now after the break-in run yesterday. LOL is there anything cheap in this hobby, I like the AMSOIL Z-ROD Synthetic Motor Oil formulation as it is specifically designed for classic and high-performance vehicles, and has a high-zinc content to help prevent wear on flat-tappet camshafts, which I am running, and its blended with rust and corrosion inhibitors for additional protection during long-term storage. I was just thinking I would run a non-synthetic quality high zinc oil for the first 1000 miles or so for additional run in and then go to the synthetic, although there are a number of schools of thought around the whole topic of engine break-in and when to run synthetic. Thanks for your input.

[70cj428]

"I also check the Carter X for fuel pressure and it puts out about 7 psi dead headed against a pressure gauge I put on the temporary fuel line when I had the carb removed."

7 psi is kinda pushing it with the stock Holley carb. The fuel pressure is determined by the spring on the pump diaphragm. I have a little over 5 psi from a rebuilt 4441X pump on my q code. Where did you get your rebuild kit ? 

John

[1970 Snake]

Good to know we have the same numbers, the speed shop told me that the holleys will handle 8 psi but if I was running a Edlebrock they don't like more than 5 psi.
I can't remember where I got the kit, its been a while and I buy parts from many different vendors.

[1970 Snake]

Just a follow up I rechecked my rebuilt Carter X fuel pump with a better gauge dead headed on the to carb fuel line and it puts out exactly 6 psi, not a big difference from my original 7 psi reading but more accurate.