Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (
-   Hotrodding Basics (
-   -   Which Elgin cam is best for TBI Torque? (

footnbruce 10-21-2016 07:47 PM

Which Elgin cam is best for TBI Torque?
I have seen a few Elgin cams mentioned here, If I can't put a GM roller cam/lifters in my 1995 Yukon 5.7 L05 TBI block, I am curious which one of the following three would be the best from idle to 3,000 RPM, (the zone I drive/tow with my Yukon)

CAM# W/1.5 LIFT @.050 Opens Closes Overlap LSA

E-274-S INT .390 194deg -12 BTC 26ABC 40deg 112
E-274-S EXH .410 202deg 36BBC -14ATC

E-860-S INT .404 202deg -14BTC 36ABC 40deg 114.5
E-860-S EXH .415 207deg 37BBC -10ATC

E-1005-P INT .398 194deg -10BTC 24ABC 50deg 112
E-1005-P EXH .420 204deg 39BBC -15ATC

From what I have learned so far (?) the larger LSA of the E-860 is good for TBI, and Torque is best when the cam opens early, again the E-860.

Just wondering if the E-274 is easier to tune with less duration?

What else am I missing?

I appreciate all the input I can get, A new cam is most likely all I can do this winter, I was hoping to go 383 but the money is just not there...

jokerZ71 10-21-2016 08:17 PM

The E 860 would be my pick.It has very similar specs to the LT1 roller cam.We have used that cam quite a bit to upgrade L05's when converting them to roller setups.Being a roller & having more lift, the LT1 cam would make a little more power under the curve, but, not alot on a cam this small.With the wide LSA, I have had them run very well without reprogramming the chip, but, tuning would give alot better results.You will at the very least need to bump the fuel psi up slightly by installing an adjustable fuel psi regulator. You will have problems with lean mixture if you don't.

vinniekq2 10-21-2016 08:26 PM

64nailhead (Jim) is currently hot rodding a TPI system. ask him

jokerZ71 10-21-2016 08:30 PM

Using a 1.6 rocker with that cam would give a little extra as well.This will give you a little more lift, faster action of the cam.

jokerZ71 10-21-2016 09:08 PM

If your willing to look outside of Elgin cams,Lunati has a couple in their VooDoo line that would work well.I'm sure the Elgin is cheaper tho.These run $114. The 1st cam is #10120700.
Adv duration is 250/256
@ .050 duration is 207/213
Lift is .437/.454
LSA/ICL IS 112/108
I used this cam in building my Dad's 93 L05 motor.He ran it for some time on the stock tune & adjusted fuel psi.It ran really good, but, he eventually had a chip burned & it really made some improvements.

The next cam is #10120701.
Specs are
adv duration is 256/262
@ .050 duration is 213/219
Lift is .454/.468
LSA/ICL is 112/108
We never tried this on the stock tune, so, I can't say how well it would work.I'm sure it would have some issues.It made really good power tho.

footnbruce 10-21-2016 09:15 PM

I like the data on the Elgin website, It's interesting how many cams share similar lift/duration, It's hard to find cam cards with degrees opening/closing.

now I hoping somebody can break down the cam opening / duration / overlap and how it applies to a L05 used mainly from Idle to 3,000 rpm.

The E-860-S cam appears to be a L98, 230hp/330tq vette cam from 1986, a vette weighs 3,100# I'm at 4,700# + 2,500# boat!

jokerZ71 10-22-2016 06:58 AM

If you could possibly be able to go to a roller setup, GM's Ramjet cam (#14097395)is a great cam for what you are wanting & cheap for a roller cam.About $160 new, or, you can often find them as new pullouts on Ebay for $125.This cam makes about 400 ft/lb from just over 2000 rpm & maintains that out to 5000 in a Vortec 350. Your L05 would drop off a little sooner due to the heads.It specs at
duration @ .050 = 196/206
Lift = .431/.451
LSA/ICL = 109/109
The 109 LSA on this cam is not a problem as the duration is so short, but, you would need some tuning changes to make it work.It would by far be about the best cam you could choose, if possible. I use this cam in my own truck & i tow approx 5000# with my horses & traler often.The stock cam is not much more than a broomstick& is more geared to emmisions & milage.The low rpm torque on these motors comes from the head design.Any of the cams discussed will give you a performance increase above the stock cam without losing anything on the bottomend. Your current motor is only rated at 210HP & 300 ft/lb.They are all short duration cams.Not high performance racing cams.The heads stop flowing at about .450 lift, going above that doesn't help anything.

jokerZ71 10-22-2016 08:53 AM

Also, if you go to Wallace Racing website, they have a cam degree calculator that works really well & can help you compare timing events between different cams.I can't get the link to post for some reason this morning. Put in the duration, LSA,& ICL to see the timing events.Just keep in mind that if you use @ .050 duration, the timing events given will also be @ .050.

footnbruce 10-22-2016 09:38 AM

I tried to use a dynamic compression calculator from a few links that were posted here when I was toying with a 383 build. I ran into a similar problem in that all the cam mfgs don't publish the "cam card" in a way they can be easily compared... not by me anyway.
Take the GM 3896929 "929" cam for example, it was used in the 8,000+ gvwr L05 and is the same as a Elgin E-274-S, or a Crane 968711 or a Comp Cams 12-105-3.
That being the case, the different mfg websites still don't list the degree of openings in a similar manner... some use .050, some don't. Most don't list the degree of overlap, how is that figure calculated???

would advancing a cam like a 929 show torque increases in the 0-3,000 range as I will never see 4,500?

footnbruce 10-22-2016 11:18 AM

My engine is as strong as it ever was. 130,000 miles, no smoke/noise synthetic oil changes every 5,000 miles since day one. I drive a friends once and a while with 289,000 miles on it, and it still runs good!

The Jeep compression ratio calculator is good, it still needs a figure most cam companies don't provide... advance angle? so if the cam is installed "straight up" I still don't know what the cam mfg has for a "ground in" advance angle....

383 is the way to go no doubt, it's $1,600-2,000 I don't have in the budget.

the stock GM 7,200gvwr L05 cam @ .050: 166/175deg, .382"/.402"lift 112lsa

every cam sold has more lift and duration than that!

jokerZ71 10-22-2016 07:40 PM

You can make some decent gains in your motor.Any of the cams you listed would makes improvement. Some more than others.The L05 & swirl port heads are not a bad combo for what they were designed for & for the use you state, fit the situation.You don't need a bigger high performance head & you definitely don't want to start porting on the swirl ports.The design of the ports & the swirl inducing vane is what makes them work & provide the lowend torque that they do.They actually make slightly more torque than Vortecs up to about 3000 rpm & from there the Vortecs leave them in the dust.Like I said & you already know, the stock cam is very weak & the stock tune leaves alot to be desired.Any of the cams listed above will work much better with other upgrades to support it.Good free flowing exhaust.Proper fuel psi & a reprogrammed chip.That Elgin cam or the smaller Lunati wouldn't have to have a new tune, but, it would make a world of difference in performance after the upgrades.What transmission & rear gears do you have?

footnbruce 10-22-2016 10:07 PM

It has a rebuilt 4L60E, 3.73 gears...k&n filter, 3" cat, 3" cat back system... A heated o2 sensor and A new better flowing 48 state flowmaster combination collector/ cat will be installed in the spring. Timing is bumped 4 degrees.... the roof needs paint, GM Olympic white peeling problem that has been fixed in a few places over the years.

jokerZ71 10-23-2016 07:17 AM

Both of the Lunati cams I listed are in the list from TBI Chips above, along with the Elgin cam you were considering. The duration of any of these cams is not gonna take away any noticeable low rpm torque.I do strongly advise you to invest in a tune tho to bring it all together. However, from my experience, I wouldn't use Bryan Harris from TBI Chips.It would be better if possible to get the chip done locally.Mr. Harris does pretty good on tunes in person, but, the mail order can be hit, or, miss & may require several chips before nailing it down without a data file to work with.
I would also urge you to convert over to the roller cam.You can usually grab the parts needed at a JY for less than $50, or, even sometimes on Ebay.Even picking up the hardware & stock Vortec roller cam would make some decent gains & be relatively cheap.The stock Vortec cam does good with 1.6 rockers also.You would then already be roller ready if & when you do go 383.Just about anything tho will work better than that broomstick stock cam.

footnbruce 10-23-2016 07:37 AM

My original post was just to give me some cam options if the engine block is not roller ready.
I think the stock 96-99 GM roller vortec cam would be great for my use.
Best practice dictates I take the intake off before ordering any parts just to check if it's ready for the roller lifter spider or not.
I found some interesting reading on a corvette forum about GM cams, those guys are all about tweaking using all the stock GM exterior components... Not just installing aftermarket manifolds/headers/heads/carbs to get H.P. improvements.
Reminds me of the kinds of mods we did for motorcycle production road racing.

jokerZ71 10-23-2016 07:56 AM

Yep, pulling the intake 1st would be a good idea.The bosses will be there.They may just need to be drilled/tapped.You want to make sure the top lifter bore surface is machined flat also for the dog bones.
Do you know which block casting you have? The #880 Vortec block was used pretty widely in 95 on some of these motors & i've never seen a #880 block that wasn't roller ready.The #638 block could be either way & anywhere in between.GM Performance also sells a kit that incudes everything except the cam & timing set, including new lifters for about $275.A couple of other places, have their own kits as well, including Summit, but, I have no experience with those.

jokerZ71 10-23-2016 08:27 AM

The cam degree calculator I mentioned earlier also gives the overlap based on the info entered.
Alot of the GM cams can be hard to figure, GM rarely provides the true ICL of their cams & alot of the published durations are listed in true actual seat to seat vs @ .004, .006, etc.
Keeping the TBI computer happy means retaining as much vacum as you can & small overlap.

jokerZ71 10-23-2016 12:13 PM

WOW!!! Almost 500 HP from the LT4 HOT cam ??? Maybe with a 100 shot. .LMAO.That's a 400 HP cam & even then an almost perfect setup.That's another story tho & beside the point.Just thought it was really funny.
The new Vortec motor would be a good choice but not what you're looking for at this time & budget would be over $2500 by the time you get it installed & running.You can do the cam swap & convert to the roller cam, if your block is ready for approx $600 & that includes a new chip.You can hit 250 to 275 HP & increase torque across the rpm range to close to 350 to 400 ft/lb relatively easy with your current motor.Just have to match it all up.Should pull that 2500# boat really well with your 3:73's.

jokerZ71 10-23-2016 03:00 PM

The LT4 Hot cam will not under any circumstances take a 350 motor to even close to 500 HP. Not N/A anyway.It's just nowhere near enough cam.Even 425/430 would be a far stretch.It takes an optimum setup with 10:1 or better & a very well tuned exhaust to break the 400 mark.The LT1 stock cam is not gonna touch 400 HP.Maybe 350.Maybe.These cams are just too small to make these #'s.The LT1 cam has less than 210* intake duration. The Hot cam is less than 220*.They are both lazylong ramped cams to boot.If what you are saying is possible, why do you regularly advise ppl everyday to use these big 240 to 250 duration cams & claim 500 HP. It takes alot of cam to get a 350 into the 500 HP range.IDK.Maybe you think that Vette emblem adds another 75 to 100 HP.

jokerZ71 10-23-2016 03:24 PM

www.superchevy. com/how-to/engines-drivetrain/1311-dyno-testing-new-mods-for-the-lt1-motor-part-2/
Not gonna turn this thread into an argument with you over your BS & false claims, as it has nothing to do with the OP's goals, or, what he's trying to accomplish.Just longwinded junk that doesn't say very much.

In a well planned LT1 on a dyno with no accessories & open headers, the LT1 cam just barely broke the 350 HP mark.The LT4 HOT cam just broke 420 HP.Even with heavily ported aftermarket heads & a 226* cam,471 HP.

jokerZ71 10-23-2016 03:45 PM

Meant to mention this earlier, but, let it slip my mind.When you do your upgrades & get to the fueling aspect, (increasing fuel to support the upgrades), don't be tempted to buy & use the 18 psi spring that Mr Harris suggests & sells.This very seldom works.Especially with milder upgrades you are considering. You need to be able to fine tune the psi to your combo.18 psi is not likely to be needed for your setup & will give you headaches upon headaches in the idling & low rpm operation.You're gonna be somewhere in the 13 to 15 psi range based on my experience.

footnbruce 10-23-2016 04:31 PM

The "tuning" aspects of TBI have me fascinated... these vintage computers must be sloooow. Before I would buy an aftermarket chip I would want to know the exact difference between stock oem and the new chip.
timing? how much do I have now vs. the new chip?
fuel? if the vehicle is reading tps, map and O2S how is the change made?
I would like to see a side by side chart/graph of both chips as a starting point.
I have not looked into what is available in the world of chip programming at all.

My check engine light came on just once when it was just under 5 years old, 70,000 miles. A new tps switch fixed it.

GM OBD1, nothing I have spent much time with..... yet!

Rhansen 10-23-2016 05:41 PM

may want to look here for more info on tuning differences/how to tune.
GearHead EFI Forums

IMHO it is better to learn how to DIY tune than to send off for a mail order type tune (seen a few mail order tunes that looked like crap on the datalogger) but the learning curve is steep and it may not be cost effective for your goals.

I have no experience with the tbi setups but am learning on a '95 LT1 B body. Told myself that I was just gonna calibrate for the new gears and done but it seems I am constantly tweaking things because I can, like a kid with a new toy....

jokerZ71 10-23-2016 05:59 PM

The pre 93 ecm is extremely slow.The 93 up are 8 to 10 x's faster & more capable.With the addition of the 4L60E, GM had to use something better.They still leave alot to be desired tho.
The mail order is hit or miss.My experience with TBI Chips & Bryan Harris was based on obtaining a tune for that larger 213/219 Lunati cam I mentioned earlier.After 4 failed attempts at getting it correct my then brother-in-law decided to start burning his own.Prior to the chips from TBI Chips, he was using an off the shelf Hyper Tech chip.When he read the tune from & the chip from the $125 HyperTech & compared it to the $250 tuned chip from TBI Chips, it was virtually identical.After a slight learning curve, he had the truck running great with no codes.

jokerZ71 10-23-2016 06:14 PM

Chip burning can be pretty time consuming.The better way if you are gonna be doing alot of tweaking is to something like the Dynamic EFI.You can tune thru your laptop & make changes without having to burn new chip with every change.
This site has some good info for tuning, fueling, etc for the GM TBI systems.

jokerZ71 10-24-2016 08:32 AM

If you're really interested in the tuning aspect of DIY,you may wanna watch the classifieds over at frequently have this stuff for sale over there at good prices,as a lot of them are either going LS,or,carb.
There's also a lot of tuning tips,& help over there as well for the TBI/OBD1 stuff,along with a few guys that offer tuning..

All times are GMT -6. The time now is 09:10 PM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.