My Flat Tappet Cam Wiped Out So I Decided To Go Roller

[L31MaxExpress]

I have another issue - when I had the original peanut cam in it, my oil pressure, when hot, was ~40 @ 2000+RPM and 10 PSI @ idle. When I put in the Lunati flat tappet cam the pressures went up 10 PSI across the board. Now, with the Comp cam, it's back down to, or a little lower, than what the peanut cam was.

I'm thinking about putting in a new oil pump (it's the original 22 year old one from Mr Goodwrench), probably a high volume. Anyone have a suggestion/preference?

M99HVS on an ARP stud is all I have run for 10+ years now building small blocks. I like that kit because it includes the pump, pickup tube and hardened steel sleeved driveshaft. I like the stud because you do not have to worry about the bolt length being wrong which will either pull threads or smash into the rear main bearing damaging the bearing and crank. The only thing I have found is the windage tray will need to be clearenced slightly to clear the larger, thicker casting. These pump do not snap in half like the thin cast replacement SBC pumps do and with the added tooth count they turn very smoothly.

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[PlayingWithTBI]

M99HVS on an ARP stud is all I have run for 10+ years now building small blocks. I like that kit because it includes the pump, pickup tube and hardened steel sleeved driveshaft

Nice, on another thread I remember someone recommending the Melling pumps. On Summit Racing site it says comes with HP spring. What kind of pressures are you getting with it?

 

[PlayingWithTBI]

At some point, sure, but I don't think 224/224 is that point. He's only 10 KPA off mine and it idles fine in closed loop

Thanks for that @arrg! I have it running in CL and my MAP is down to ~45 - 48 with 28° timing. BTW, lowering AFR didn't seem to lower MAP appreciably so, It's staying at 14.7 for now.

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I am getting some (not a lot) KCs which is pulling ~3° Timing with WOT, I need to address. I still have PE adding 3 so, I may drop 1 or 2 to see what happens. I may even lower knock Retard Attack and Recover rates. It's still running rich, I need to lower my VE tables at higher MAP/RPMs too.

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So far so good, I'll run a while and let Int/BLMs play with each other.

Monday we're gonna attack the oil pump replacement. FWIU, with my C1500, I can drop the pan without jacking the engine up. I seem to remember someone saying to rotate the crank until it clears, anyone ever do that?

Again, thanks to everyone and, all comments/suggestions are greatly appreciated!

 

[L31MaxExpress]

Thanks for that @arrg! I have it running in CL and my MAP is down to ~45 - 48 with 28° timing. BTW, lowering AFR didn't seem to lower MAP appreciably so, It's staying at 14.7 for now.

You must be registered for see images attach

I am getting some (not a lot) KCs which is pulling ~3° Timing with WOT, I need to address. I still have PE adding 3 so, I may drop 1 or 2 to see what happens. I may even lower knock Retard Attack and Recover rates. It's still running rich, I need to lower my VE tables at higher MAP/RPMs too.

You must be registered for see images attach

So far so good, I'll run a while and let Int/BLMs play with each other.

Monday we're gonna attack the oil pump replacement. FWIU, with my C1500, I can drop the pan without jacking the engine up. I seem to remember someone saying to rotate the crank until it clears, anyone ever do that?

Again, thanks to everyone and, all comments/suggestions are greatly appreciated!

I have had to rotate the crank a few times to get a pan past the counter weights. No big deal there. Once its rotated the pan may fall out on its own though.

I do see a little low hanging fruit in your tune. At WOT the EBL settings can be adjusted to allow for more than 145 IAC steps. IIRC 255 steps is the limit of the code. You are at 88 KPA MAP and opening the IAC will allow some additional airflow through the same throttle body.

I do not remember which ignition control module you are running, but if it is a GM 369/ACDelco D1943A/Davis Unified and you are commanding 36* of timing, you may be seeing as much as 38-40* of total timing. Most of those modules seem to have an additional 2* advance above 4,000 rpm over commanded using the stock latency values in the ECM. Most of these more modern aluminum heads have chambers that only need 28-32* of timing at WOT on pump gas. I would put money on a bet that the difference between 28 and 34* would be less than 5 hp and that 34+ would actually cost you power even if you did not see knock retard.

 

[arrg]

Thanks for that @arrg! I have it running in CL and my MAP is down to ~45 - 48 with 28° timing. BTW, lowering AFR didn't seem to lower MAP appreciably so, It's staying at 14.7 for now.

Glad that worked out for you!

 

[PlayingWithTBI]

if it is a GM 369/ACDelco D1943A/Davis Unified and you are commanding 36* of timing, you may be seeing as much as 38-40* of total timing

It's the ACDelco D1984A, do you know how it affects total timing?

You are at 88 KPA MAP and opening the IAC will allow some additional airflow through the same throttle body.

I'll play with that to see what happens. I was thinking maybe going with a 50mm TB instead of my 46mm one? I have the manifold bored out to 48mm.

 

[PlayingWithTBI]

Most of these more modern aluminum heads have chambers that only need 28-32* of timing at WOT on pump gas.

Yeah these are 62cc chamber, 2.02/1.60, 170/64cc runners, "fast burn", with angled plugs.

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[L31MaxExpress]

Yeah these are 62cc chamber, 2.02/1.60, 170/64cc runners, "fast burn", with angled plugs.

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I have a straight plug version of that style chamber on my 383 and it makes best power at 31° on 91 and 34° on E85.

 

[PlayingWithTBI]

it makes best power at 31° on 91 and 34° on E85.

Right now I'm running 87 and was hoping I could get by with it, at least during the cooler months

 

[L31MaxExpress]

It's the ACDelco D1984A, do you know how it affects total timing?


I'll play with that to see what happens. I was thinking maybe going with a 50mm TB instead of my 46mm one? I have the manifold bored out to 48mm.

Above 4,000 rpm they generally advance 2° over what you have commanded.

I would try the throttle follower IAC trick before spending money on a larger throttle body. I used a 454/Marine TBI with an Industrial/C60 truck injector pod and the Brazilian I6 injectors that are ~120 lb/hr each when I was making real power with TBI.