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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Back in the day, some of you may recall that I had an '83 CFI TA with a SBC 400. That engine was a stock-dog long block, with a heavily ported CFI intake, headers, 1.5 RR's, other meaningless mods and a cam. The cam was an el-cheap-o, SUMMIT 1105. So you don't have to look;
224/234 @ .050
.466/.487
114 LSA
Tell me how that cam should idle (in a 400), at 6-700 RPM....
Without knowing EXACTLY what ICL it was installed at, my guess in an overall general way would be:
Slight to very moderate chop (not rowdy or anything, just, barely noticeable)
Idle vacuum 16 - 18in out of gear, 13 in gear
Also without knowing much about the CFI's tolerance for such things, I'd guess it should have run "OK" on the stock tune, if a bit ... stumbly ... at times, off idle
Woulda run out of breath BIG TIME by around 4500 RPM or so, maybe sooner, given that "porting" that intake is kinda like putting lipstick on a pig and calling it a supermodel, since there's nothing there to port
Probably pretty smooth given the wide LSA and relatively mild duration and lift for a larger displacement sbc. Could be a little choppy, but also perhaps not depending on the specific valve timings.
My AI agent I built for engine combo nerdery says it's lopey but stable, 12-14 inHg at 600-700rpm, probably smoother at 750, right on the edge of what the stock ecm can handle.
Is this for the grenaded 305 Vortec truck? My guess it will be just beyond what a Black Box Vortec will be happy with for a decent idle. I ran an Elgin E1136, 210/215 on a 110 LSA roller in a L31 I put into an Escalade on the stock tune to see what happened. It ran but definitely ran better with tuning. It logged a ton of misfires on the stock tuning and I had to loosen up the misfire detection for it to consistently lock the converter clutch and not throw P0300 codes. The GM 7395 Marine/Ramjet/HT383E 196/206 on a 109 logged misfires in my 97 running on a later 2002 0411 PCM but GM was really tightening up the misfire detection for emissions reasons by that point. My brothers 99 Suburban with a factory 1995 LT1 F/Y car cam also logged enough misfires to prevent lockup and throw random P0300s. You might get away with one step smaller, the 214/224 in the 400 because of the flat tappets smaller area under the curve and the 400s added cubes but I would not count on it and understand tuning might be needed to get it to drive halfway decent.
Id expect it to be pretty tame to be honest. As sofa said, maybe slight idle chop so you know theres a cam in it but wide lsa and relatively low duration will hide it abit. Should be a good driving cam. Good exhaust can also dampen the lope and make it seem tame.
if tune was good with no air fuel imbalance across cylinder i would expect it to be pretty stable and not fussy at all.
Id expect it to be pretty tame to be honest. As sofa said, maybe slight idle chop so you know theres a cam in it but wide lsa and relatively low duration will hide it abit. Should be a good driving cam. Good exhaust can also dampen the lope and make it seem tame.
if tune was good with no air fuel imbalance across cylinder i would expect it to be pretty stable and not fussy at all.
If it is for a Vortec Black box for the spider injected Vortec truck, pretty much every cam is fussy. The newer the PCM the tighter windowed GM calibrated it for emissions reasons. The 96/97 are a little more forgiving and the 98+ are more picky but more tuning options on those. The 01+ 0411 and 03+ P59 is even more picky misfire detection wise although signifigantly improved in other ways like dual timing maps, more resolution to the timing advance tables and VE tables, individual cylinder knock detection so it will only pull timing from the cylinder that is knocking, better idle control, better transmission control, more advanced torque management, etc.
Tom has not mentioned specifically on the details of what he is doing with this 400 but I have a fair idea based on a prior post. I have a lot of experience modifying these engines and my gut instict says the Black Box will be pretty ticked off with that cam although a tuned P59 would run it great. The Mexican GMT800 L31 trucks came with a DBC P59 that was setup for the 5spd they used in them. There are signifigant engine and exhaust calibration differences due to the exhaust/02 configurations between a 305 and 350 as well as an automatic and manual transmission. If Tom were to ship me a DBC IAC driver equipped Blue/Green connector P59 I would put together a base tune file for a 400/5spd and send it back to him. I know for a fact the P59 would happily run that combination with that cam anyday of the week and every given Sunday. From personal experience it takes about 2 hours to repin the stock harness to the newer PCM connectors and clean it all up after taking your time doing it. I will also add I do not feel that the 400 would be overly happy breathing through the restrictive TBI 350 era single catalytic converter and smaller Y-Pipe the 305 trucks used. From memory it is like 1-7/8" off the manifold and 2.5" outlet Y-pipe. The 8-lug 350s used 2.75" or 3" dual pipes and the same cats 454s and 8100s used from the factory and are far better better breathing.
Fast is right and astute about my "BIG PLANS!" for a 400 in the Grandpa truck (to replace the lamest 305 ever made). But those plans changed...I bought a low mile, super clean, 1996, x-cab/s-bed, 4x4, with a 5.7/5 speed. I'm not going to waste a 400 in the Grandpa truck, now -that one's getting a jy 350 and then it's slide right into the classifieds and go bye-bye.
Instead, the 400 had planned for the Grandpa truck, is now going into the Kart, and I'd like a cam that has about the same characteristics, that the old TA/400/cam combo had.
Originally Posted by Orr89RocZ
Id expect it to be pretty tame to be honest. Should be a good driving cam. If tune was good with no air fuel imbalance across cylinder i would expect it to be pretty stable and not fussy at all.
You get "the prize". It was a pretty great cam in that crappy engine. It idled like stock. You could not tell it had a cam at all. It started, and idled exactly like the original (basically stock) 305 did. It has killer throttle response and great drivability. It "pulled" good to ~5500 (SOTP), I got my fastest ET's and traps (mid 13's/105ish) by shifting at 5200. Icing on the cake was that it still got 24 mpg consistently on road trips. I thought that cam worked pretty great. I'd like something similar, but roller. My concern is lumpy idle and off idle drivability, but I can't see why a same/similar duration roller should be any different than the 1105 was.
Do folks agree?
Last edited by Tom 400 CFI; Jul 24, 2025 at 08:38 PM.
Keep the wide LSA and you'll preserve the idle. I think to get the equivalent effect of the flat tappet you might want to go slightly milder on the roller to account for the higher ramp rate / greater open time. Might be more fun to do almost the exact same thing but roller, it certainly wouldn't be too much.
Roller will have much less advertised duration and should be closing sooner/opening later the valves off seat while gaining area thru faster acceleration and lift. So i would think something similar spec at .050 with lesss advertised and a 112-114 lsa would do well. Comp had a old cc305 cam that was 220/230 on a 114. Ran very mild like in 350 LT1 cars in the day. Even the lt4 hot cam. I ran one in a 350 tpi and it was very smooth in that car. Also had one in a lt1 i tuned, same thing
The CC305 is listed as 220/230 .510/.510 114 (with 1.5 rockers) The LT4 Hot Cam is 218/228 .525/.525 112 (with 1.6 rockers)
both have lazier lobes that are soft on parts. A quicker lobe like 268xfi 218/224 would be nice too. But comps cam prices are ridiculous now
Last edited by Orr89RocZ; Jul 25, 2025 at 09:50 AM.
A bit big. Will hear the cam. Can drive well tho if tuned depending on ecm. If this is some kind of truck intake and old school electronics like Fast355 said, i am not sure how it will do.
this is a 9:1 comp 400” sbc with a 233/233 .564 112 turbo cam
This is for the Kart, so older than trucks. the Kart was an '89 'Vette.
That idle would be fine in the Kart, but that's ~10* less degrees on the exhaust.. OTOH, tighter LSA. That might be fine in a "toy" like I'm talking about. How was the low end tq/driving away from a stop w/that combo?
I'm not sure lightly worked 113 heads are going to support the kind of flow that biggest cam is looking to do.
Depends on what is done to the 113s. Lingenfelter was getting ~270 cfm out of them. Lloyd Elliot gets about the same out of similar stock GM LT1 castings.
i'm sure that you're right. I was figuring that the duration would help the head....the lift is probably wasted.
The fastest SBE LT1 cars back in the day with stock heads had one thing in common. A CC-306 cam and they were spinning the snot out of them. 230/244 @ 0.050, 0.510/0.540 lift on a 112 LSA. The fastest of them were shifting over 6,500 rpm with stock heads even.
Chad speier got decent numbers out of his 113’s. They wont go as far as lt1’s but even 250 cfm can make 500+ hp
my 233/233 had a ton of torque lol it was a good driving setup on stock ecm with tuning. Single plane efi intake. Afr 195 heads so it was a low rpm torque deal
I agree about sustained RPM over 5500. I wouldn't expect it to tolerate that for long. I'm sure I will blast it to 6 occasionally in low gears,...I expect it could take short durations for a while....but....I don't care about longevity (if it ralphs) too much, either. It's a toy...not a driver. we're talking <$1k engines, here.
Tuned: The Kart is (was) an '89....so not xfire.
Last edited by Tom 400 CFI; Aug 1, 2025 at 03:46 PM.
Back in the day, some of you may recall that I had an '83 CFI TA with a SBC 400. That engine was a stock-dog long block, with a heavily ported CFI intake, headers, 1.5 RR's, other meaningless mods and a cam. The cam was an el-cheap-o, SUMMIT 1105. So you don't have to look;
224/234 @ .050
.466/.487
114 LSA
Tell me how that cam should idle (in a 400), at 6-700 RPM....
Or you could keep to the topic and not be so scattered.
Good advice. If you want to nit-pick the manner in which I choose to post MY posts in MY threads, consider that ^that^ was about as helpful to this thread as....
....when I never asked, "how should I toon my kar, bro?". What I actually asked (and I did it right in post #1), was:
Originally Posted by Tom400CFI
Tell me how that cam should idle (in a 400), at 6-700 RPM....
Maybe that was...too "scattered" for you?
Originally Posted by Tuned Performance
But I doubt your doing or having any tuning done. Just a glorified carb that’s not right.
Not sure WTF you're talking about here. Krystal ball stuff? You can see the future? Into my mind? Pretty weird ****, dude. I can't see how that helps anything...at all.
No hatred here....how'd you get to that!? You're the one calling names, now; show me where my "hatred" is, exactly? I'll hurry and go correct it, right away!
Originally Posted by Tuned Performance
I sure hope others help you out, being a ***** on every post instead of taking in information you dish out hatred.
You'd know about being a one, it appears. Appreciate the name calling. I "get it" though...that's were people go to when they know they're wrong. I'm used to seeing it. Post 31, reported.
What are you actually trying to accomplish in this thread, at this point? My questions were answered a while ago, the last on July 28 -4 days ago. I welcome the helpful input from all of the posts from that point and earlier; they were all....great. The GOOD replies spoke directly to my question(s). No one had a hard time understanding what I was asking....and no one talked about tuning options for CFI or tried to "predict the future" of what I may or may not do. So....what exactly, are YOU doing, here? What information are you sharing, that I should take??
Last edited by Tom 400 CFI; Aug 2, 2025 at 12:28 AM.
^That, I "get". As Denzel Washington said, "Explain it to me like I'm a 5 year old"....
Is it that you’re not understanding something ? This public forum is to help each other out not snap each others heads off. Just offering advice that it seemed like you were turning a deaf ear to. Kinda like your intake tests. Doesn’t show actual results. No tuning or afr.
Lift: .502''/.510'' Duration: 276°/282° Lobe Separation Angle: 110°
Xtreme Energy XR676HR Retro-Fit Hydraulic
not the cam you were looking for but idles at 750 in a 400 sbc with tuned port. 440/500tq at sea level.
This public forum is to help each other out not snap each others heads off. Just offering advice that it seemed like you were turning a deaf ear to. Kinda like your intake tests. Doesn’t show actual results. No tuning or afr.
Perhaps I'm "turning a deaf ear" b/c I didn't ask for and/or I'm not interested in the CFI tuning (I don't have a CFI car at all -and haven't for 23+ years), and there are instances where I don't want to tune, for specific reasons. In my intake test thread, for example, I explained that I didn't tune and didn't want to, for a specific reason. As a reminder, here is that reason, again:
Originally Posted by Tom 400 CFI
MY biggest point of interest was, as I said in the first post; "What'll she do?" Meaning, let's say that it's 1993. We/you/I/any of us are our current age and have our current "means", but it's 1993 and we have a nice 3rd gen, a C4....with TPI and we have some money to spend on 'em. The cars are still pretty new and we're all likely battling GN's and 5.0's at the strip and likely early in our mods with stock displacement....most of us. We're debating an intake swap....how does the T-Ram rate? Would that be a good mod? Would it be one of the better intakes? I've always believed that it would be the BEST intake for that scenario, but in 1993, I had an '83 F-bod, with an LU5 and no money for intakes (or much else).
Back then...in 1993...ish, NOBODY was tuning anything. No one knew how, had the tools or resources to do that, so everyone was tuning w/FPR adjustments, FMU's at best and buying worthless "perf chips" which we all know how effective those are, today. Modding back then was for the most part, parts R&R b/c we couldn't tune, in those days.
Other's agreed...
Originally Posted by TTOP350
I like how this shows the real world "bolt on and go" approach that was the norm back in the day.
I think in 1993, most people would have been ecstatic to get 48hp/33tq from bolting an intake onto a TPI engine and ecstatic to know, which intake would do that.
It was my engine, my tests, my $$$ spent, my time, and my thread....doing it for my reasons. Criticize and try to diminish the effort all you want, it was the test that *I* wanted but the forum benefits from my sharing of MY tests whether you like them or not. One of the great things about a public forum and "helping each other out", is that you are quite welcome to do your own test, just like I did, spend all of those resources and time, do it anyway that you like with tuning or not...and post those results. I welcome it. The forum would welcome it. Try that rather than attempting to dig at the test that I did, for my own reasons.
Last edited by Tom 400 CFI; Aug 2, 2025 at 01:50 PM.
Perhaps I'm "turning a deaf ear" b/c I didn't ask for and/or I'm not interested in the CFI tuning (I don't have a CFI car at all -and haven't for 23+ years), and there are instances where I don't want to tune, for specific reasons. In my intake test thread, for example, I explained that I didn't tune and didn't want to, for a specific reason. As a reminder, here is that reason, again:
Back then...in 1993...ish, NOBODY was tuning anything. No one knew how, had the tools or resources to do that, so everyone was tuning w/FPR adjustments, FMU's at best and buying worthless "perf chips" which we all know how effective those are, today. Modding back then was for the most part, parts R&R b/c we couldn't tune, in those days.
Other's agreed...
I think in 1993, most people would have been ecstatic to get 48hp/33tq from bolting an intake onto a TPI engine and ecstatic to know, which intake would do that.
It was my engine, my tests, my $$$ spent, my time, and my thread....doing it for my reasons. Criticize and try to diminish the effort all you want, it was the test that *I* wanted but the forum benefits from my sharing of MY tests whether you like them or not. One of the great things about a public forum and "helping each other out", is that you are quite welcome to do your own test, just like I did, spend all of those resources and time, do it anyway that you like with tuning or not...and post those results. I welcome it. The forum would welcome it. Try that rather than attempting to dig at the test that I did, for my own reasons.
just curious when you tune a carb do you read plugs or use a wideband gauge.
I guess it’s best to say you think tuning is black magic or snake oil. I can see the testing change in air flow changing hp and tq but it’s not optimized. Arizon speed and marine in 92 came out with a hac dos based program it was expensive at the time but you could edit the tuning binary. Soon after tuner cat took off and tpis started offering dyno based tuning. Don’t see I was going off on cfi, your first post indicated that’s what you were working with. Hopefully slapping parts on a 400 tpi based car works for you.
Dude, you don't "get it". Or maybe you're lost? This thread was about cam. Cam. Not tuning. Cam.
It doesn't really matter how I tune carbs, what I think about ECM tuning or really anything else you posted in this thread....none of it matters to you, or this thread. I love your speculations and ASSumptions about what I think, believe and what I'm "going to do on a 400".....your "glass ball" is quite impressive! (the ignorance is sort of funny)
RE: 10x the tork, take too!" tests, as I said above, stop criticizing...and SHOW US. Run your own test and stop bitchin' about mine. Let's see it, bud. I'd LOVE to see a thread where you dyno test as many of...anything, as I did. SHOW US, bud.
Look Brian, I "get it" that you're trying to "save face" at this point in this thread, but it's not working and it's not helping your "look" at all. How about cam shafts? Have any relevant experience w/cams in the 230's 240's in 400's? Otherwise, you should probably stop posting here, and get back to pontificating about your mad tooning skillz and recycling marked up, over priced TPI junk in the classifieds.
Mods should lock this'n up. The info that I was actually looking for was presented, I "got it" (thanks to everyone else!) and Brian has wrecked it by taking it to a totally different topic that no one was asking about....and then arguing a one sided argument about that!
Dude, you don't "get it". Or maybe you're lost? This thread was about cam. Cam. Not tuning. Cam.
It doesn't really matter how I tune carbs, what I think about ECM tuning or really anything else you posted in this thread....none of it matters to you, or this thread. I love your speculations and ASSumptions about what I think, believe and what I'm "going to do on a 400".....your "glass ball" is quite impressive! (the ignorance is sort of funny)
RE: 10x the tork, take too!" tests, as I said above, stop criticizing...and SHOW US. Run your own test and stop bitchin' about mine. Let's see it, bud. I'd LOVE to see a thread where you dyno test as many of...anything, as I did. SHOW US, bud.
Look Brian, I "get it" that you're trying to "save face" at this point in this thread, but it's not working and it's not helping your "look" at all. How about cam shafts? Have any relevant experience w/cams in the 230's 240's in 400's? Otherwise, you should probably stop posting here, and get back to pontificating about your mad tooning skillz and recycling marked up, over priced TPI junk in the classifieds.
Mods should lock this'n up. The info that I was actually looking for was presented, I "got it" (thanks to everyone else!) and Brian has wrecked it by taking it to a totally different topic that no one was asking about....and then arguing a one sided argument about that!
🤔 guess you have a issue with some people mainly me. When others suggest tuning you don’t jump their **** 💩
I might....if I was getting "lectured" about tuning "hatred" and other untrue, misguided gems, when I was asking about cams. Other than that, I have no problem with you.
Wow, that's great. Thanks for posting that one. To me, that's a lot of cam, and it still doesn't sound that "bad" (or good, depending on what you like)....it doesn't sound like it's about to stall. Good vid.
950-1000 rpm idle. Single plane with efi, ran good on a stock 730 tpi computer just tuned well. Definitely soft down low compared to the 233/233 cam but that also had afr 195 heads vs a ported rhs that was closer to 245 cc, so it was soft but drove fine
Not sure WTF you're talking about here. Krystal ball stuff? You can see the future? Into my mind? Pretty weird ****, dude. I can't see how that helps anything...at all. 
