Looking for advice on a flat tappet cam. Ive used edelbrock performer and a summit 1104 on other engines in the past, but they seemed to be lacking.

355
9.5:1
mildly ported 882 heads 1.94/1.5
performer intake
non cc qjet
headers
flowmaster
5spd
3.73 gears

The goal is to meet or exceed the over all grunt and performance of a 91 vette i used to have. It was a mostly stock L98 6spd. Daily driver, torque is very important. Must pass emissions(shouldnt be a problem on a such a buildup)

I appreciate the help, and any predictions on performance to expect.

 

Do you need a roller cam or a flat tappet cam? If its a flat tappet, something like the Xe268h would work. If its a roller, something such as a Xr270hr would be ok.

 

A Performer or Summit 1104 is about all 882 heads can handle - even ported.

 

No cam in the world will fix that.

I doubt you have any 9.5:1 with those heads, unless you have domed pistons; and if you have those, you're pretty much doomed anyway. I can't count the number of people I saw build that motor all through the 70s and 80s; take yerbasic L48, put in "pop-ups", stick one of those old "Stage 1" cams (that's what that 1104 is....), and run high 14s in some Nova or other 3000 lb car. And then wonder what went wrong. After a couple of them, I wouldn't even build them for people any more, because I knew they would come back complaining. The money I could make wasn't worth the hassle.

Put some real heads on there; get a ZZ4 intake instead of the Performer; and try a Comp XE262, or a similar "intense" grind (look at the difference between seat duration and .050" duration for a clue to that) from Crane or Lunati or some other company that R&Ds cams instead of copying copies of copied copies from the Stone Age. A good head casting to start out with, if your pistons are flat-tops or very slight dish, is the L98 heads (083 casting). If your pistons have deep dishes, 305 heads such as 416 or 081 are a good substitute.

 

its actually 9.41:1 with the 0.39 felpro im using, I measured, i'll get some better heads if your buying. this is what i have in the garage or what came with the car, im not spending any more money. As noted im not trying to make a 400hp car, im trying to get the camaro drivable with the best possible outcome for what i already have.

This would be the 3rd time ive used ported 882 heads since they were what i had, last time they were on a 14 sec flat crossfire, (of all things) which was quick enough for a commuter car.

Once again, just looking to maximize what i have, this isnt a hi-po buildup. I bought the car dead, i just want to drive it.

Review my goal in the first post "1991 L98 vette"
thats a 250hp engine = easily obtainable

 

XE262

 

thank you for your non judgemental advice

 

There is a difference between "judgemental" and "realistic".

What you received was the latter.

Nobody can make you drink, of course.

 

take the blinders off your eyes and learn everyone isnt trying to build a 12 sec street machine, show me where i said im going to slap these **** heads on and make 450 hp

you guys really need to get off the one track frame of mind

 

If it were me, I'd use the Comp Cams helpline or mail in the engine spec sheet in order to get a recommendation. Get as much info on hand as possible about the engine, car, and drivetrain, and they should be able to get you what you want.

Be sure to tell them this too:
=============
The goal is to meet or exceed the over all grunt and performance of a 91 vette i used to have. It was a mostly stock L98 6spd. Daily driver, torque is very important. Must pass emissions(shouldnt be a problem on a such a buildup)
==============

That's the best objective advice I can give, rather than make a recommendation of my own.

On a non-objective tangent (heh heh), I don't understand why so many people get cam advice on the internet, when Comp has a free hotline you can call up, in addition to a form you can fill out and mail in.

Sure, I'm interested in what other people are running, but in the final choice I'd rely on the professionals to make the call.

 

I think its because there advise varies every time you call, and is usually not the best.

 

So which cams did they recommend to you?

 

I apologize for honesty, willingness to help, and for having plenty of experience to draw on. I'm sorry if it wasn't what you wanted to hear, but that's the way the cookie crumbles sometimes.

I take it that these observations were made on engines with these same heads?

Many people here, myself included, have had lots of opportunities to see the results of exactly what you're doing. At one time it was the single most popular mistake in all of the hot-rod hobby. We would like to help you avoid that mistake, but that's your choice ultimately. Ain't happening with those heads, no matter what cam you put under them. That Vette would have been a low-mid 14s car; I don't think there's any way you'll get there with those heads. You'll have a tough time even cracking onto the 14s at all with whatyou've got. You're headed for a disappointment and reality check. You can't have it both ways.

So forget my advice and do whatever you want. I hope it turns out differently from all the other millions of the same failure that people have created over the last 30 years of the existence of those castings. But I wouldn't hold my breath expecting miracles if I were you.

Have a nice day!

 

I’m usually a mild mannered sort of person… that is until I take exception to something.



You came here asking for somewhat specific advise with regard to performance and when you get your answers you flip out and make some fairly comical accusations in a childish fit of rage. Are you above reproach? Did you not ask the questions?

I don’t believe anyone told you to do anything to push you into the 12’s. It is fairly obvious that short of some incredible synthetic aspiration, you would not come close to 12’s with those heads. Put the damn crack pipe down and start listening!! You were after all the one asking the question. If you don’t want to hear the answer, don’t ask the question!

Kinda like eating in China and asking what’s in the soup, no?

And yet…

What the boys were trying to tell you is that you are going to have lots-o-problems achieving this goal ('performance'). Why the hell are you tripping?? Why not trysomthing out before you post so you have some idea…



So from what I can tell you were previously disappointed with the performance of the cam that is probably very well suited to the head? Did you have to have a fit when people tried to tell you that you would not get ‘performance’ from that set up?

Sorry, but no one here can change the laws of physics, you want that, go to a ***** board, I’m sure they will be willing to give you some stickers.

You may want to define ‘performance’. A 14/15 second car to me is my family car. Performance would be my Cobra. You will get as specific an answer in relation to which you specified in your question.


Hope that helped. Oh and uh...


This ends our public service announcement brought to you by the Darkside. Please join us over here on the Darkside where everything is, well, dark. Your regularly scheduled program will resume posthaste.

 

Just how horrible are those heads anyway?

Does anyone have flowbench numbers?

Are they worse than 305 LG4 heads? Some guys have 305s into the 13s using the original heads. Are you saying that this guy's heads are so bad that they will only go high 14's on a 350 engine?

(speaking of flowbench data, I have the numbers from a light porting job I did on 1985 LG4 heads, if anyone wants to compare. )

I just find it hard to believe that this engine can't be built to push a thirdgen to low 14s or better. I do agree that it would help a lot to use a modern cam grind.

 

http://www.chevyhiperformance.com/te...98/index4.html

 

882s are the WORST heads you could possibly use to build anything thats supposed to be even remotely quick, except maybe the '55 265 heads.

There is a reason that 882 heads cannot be given away... no one wants them because they have no potential! The chambers are too big, the valves and ports are too small, and the casting is too thin.

The rest of your buildup actually looks pretty good, but the 882 heads (if you use them) would be SERIOUSLY holding that engine back.

What you need to remember, is that the heads are the single most important factor in how much power any given combo will make, and you are really limitting yourself by using those heads.

Now... if you used a good set of cylinder heads, like the old double-humps, or either of the TPI heads, you would be alot happier with the motor.

 

From the linked page:

==========
This aluminum head was used on the Corvette TPI engines from the mid-Eighties until the LT-1 1992 motors were introduced. The 882-iron head out-flowed this head across the board. This piece is not our first choice for a performance head considering that the largest valve this head fits is a 2.00/1.55-inch combination and it has a 58cc chamber.
============

By their data, the 882 outflowed the the L98 head. The only disadvantage of the 882 from a power standpoint is the large chamber and small port volume. This isn't a huge concern on a mild street motor though.

 

I built up a 350 with a 400 crank, short rods and 350 flat top pistons. I installed the 1103 Summitt cam with cheap 1.6 ratio rockers. The heads are cheap and plentyful 993s that I home ported and installed 2.02/1.60 valves into. The auto has a 3.73 posi rear (81 Z-28) and a 4 speed with shorty headers and dual 2 1/4th inch exhaust. That little sucker will flat boil the hides in first and second gear! With five kids, I simply don't have the bucks for expensive heads. There's hope for poor slobs like me because the old junky heads can make power!

 

Sometimes you have to go with what you have. The man has mildly ported 882 and wants some help on a cam.

As was harshly pointed out,,, the 882 are not the best set of heads for a serious performance build. However,,, you said all you wanted was something to equal the power the 91. The TPI intake was what gave the 91 Vette it's grunt,,, and you're going to have a hard time getting the same grunt from a performer intake. But there are a couple of ways to increase midrange power on ANY set of heads.

One is to run full-length headers over shorties. That may not be an option and you didn't ask about headers,,, but a decent set of 1 5/8" LT headers can add as much as 20 -25 lb/ft midrange torque (depending on the combination).

The 882's are not terrible as far as stock heads go. The chambers are large which can kill compression,,, but if you're sure you have 9.5:1 compression with the heads, then you'll have a chance at being somewhat satisfied.

Another way to boost midrange torque is to run a tight lobe spread cam. The 1104 is probably the absolute WORST street cam EVER. Extremely slow ramps and cut on a 114 spread.

Go with at least a 110 spread,,, and I'd go with a 108 spread cam if you're decent on tuning a carb. This will bring in the power curve quickly,, it will also drop off the power curve quickly. But if grunt is what you want,,,, it'll be what you get.

The 882's exhaust is a little weak compared to other stock heads, so you'll want to go with a split pattern cam. The split pattern cam will also give you a few more RPM than a single pattern cam,,, which is good if you go with a 108 spread.

Comp X-treme energy grinds are very good, but the off the shelf grinds don't have enough exhuast split for you. I'd go with a 108 spread, 218-224 degrees on the intake and add 6 degrees to the exhaust if you're running a dual exhaust system,, or 3.5" single exhaust OR,,, add 8 degrees to the exhaust if you're running a single 3" exhaust or less. If you're not confident in your tuning ability,,, go with the smaller end of the recommendation (or a couple degrees less).

Guaranteed improved results over the 224/224 -114 cam.

 

Half you guys actually have a level head on your shoulders, the other half spends way to much time on the internet enjoying their own superior intellect. Post count does not equal experience. If it did i direct you to a couple corvette groups.

You automatically assume because someone is using inferior parts they deliberatley picked them, and they have no clue. I didnt buy a single part for this car let alone a basic rebuild kit for the engine. Im just working with what came with the dead iroc i bought.

The last car i did some work on was an 84 corvette, it had ported 882's, headers, 1104 cam, some exhaust work, crossfire injection, 3.08 gears no tuning at all and it ran a best of 14.04. It was also a cheapo buildup for under 500 dollars.

And half you guys are telling me a similar buildup with a better cam, better compression, and NO crossfire cant do that? please..

I also appreciate how my post was hijacked and made about heads, in order to work out some deep rooted psychological issues they have regarding them.

Whats the matter your momma gave you an 882 head to play with as a child instead of a puppy?

 

No; some of us have taken them off, thrown them in the trash, and picked up an AMAZING amount of power with other junkyard heads.

Like Red Devil said, be prepared for hearing some things you don't like when you post stuff on the Net. You'll get alot of spank-off, and alot of holier-than-thou disrespect; if you're lucky, you'll get some sound advice.

I don't read a bunch of magazine articles to come up with what I know about building motors. In the process of acquiring kowledge about building motors, most of what little I know about building motors, came from BUILDING MOTORS, not reading magazines or reading postings on the Net.

But like I said, if that's what you have, and you're just bound and determined to run them, then be prepared to accept the consequences..... defeat and disappointment. It's not my problem. I scoured the junkyards and found decent castings, and put my money there, instead of a bunch of thin smogger lightweight garbage that doesn't port without cracking and has a terrible combustion chamber shape. Basically a bathtub with a couple of pockets.

There's one hell of alot about heads, besides just raw flow numbers in their stock cnodition, that makes them good or bad for a performance application. 882s don't have any of it.

The best thing you can do, is to use a cam with LOTS of exhaust lobe, to overcome the very poor exhaust port configuration of those heads. It won't cure their other shortcomings, but it will help. An even better thing is to cut your losses as soon as possible; put not one more dime into those inferior castings; and go out in search of some better ones. You could do as all of us who have been building motors since .... well, for many decades.... and find some old double-humps such as 186s, or you could locate some L98 heads, or even certain later-model 305 heads. The late model heads are on the classifieds on this site almost continuously, for so little money that it's almost shameful. Any of those will give you a vastly superior motor to what you will end up with using those smoggers. Regardless of the cam you put under them.

You asked for advice, you got advice, it wasn't what you wanted to hear. That's OK as far as it goes, advice is yours to use or ignore, at your own peril either way. Don't attack the advice-givers because you don't like the reality they expose you to. We advise you not to use those heads, no matter how "free" they are; if "free" is that important, then you don't need our advice, since you're going to use your "free" stuff anyway. You asked what you could expect, we told you. Sorry if it wasn't what you wanted to hear.

I hope next time I go to the track, you're the guy in the other lane.

 

I've seen the Summit cams used before in magazine dyno tests. Sometimes it had me scratching my head because it seemed that the HP peaked rather early considering the duration of the cam.

But like Kevin pointed out, those Summit cams use a very large lobe separation, so that may be part of the problem.

If your heads are a very thin casting, then you may not want to do the machine work to enlarge the spring pockets to fit the springs needed for the Comp Extreme energy cams.

If I had to choose, I'd try a Dual Energy 265DEH:

211 / 221 duration
.442 / .465 lift

I believe the springs for this cam won't require head modification. The rpm range is listed as 1500 to 5750. The note says "very strong mid range, lopey idle, everyday performance for stock exhaust". This cam is also emmisions legal.

I think with the small intake port volume on the 882 heads, they'll be done making power by 5000 rpm or so. The rpm range of the cam is a little bit high in that case. But you said you have the lower gears, so it could work out okay. If in doubt you can go one step back to the base dual energy cam. These cams should be reasonably priced too.

Again, I'd get a recommendation from Comp before buying

 

My suggestion: Look for 416 heads. They are on almost EVERY 305 you will ever find, and they are far superior heads to the 882s or 993s.

They have small chambers, they flow alot better than almost any smogger 350 casting (ie. 882, 993...) and they are not 'lightweight' castings that crack when you port them.

And, since they are "just 305 heads" you could likely get a set of those even cheaper than any 350 heads, if not even free!

 

No, you didn't ask for advice on heads.

However, you did ask about a cam, and the good thing is you included the info on the rest of the "package". That's good, because the rest of the "package" is very important when making a cam choice.

The bottom line is the heads are the restriction to the performance you said you're looking for. Therefore, the effect of the cam will be limited. As RB said, try to maximize exhaust on the cam, but even that is only going to have so much affect.

A good salesman is the one who sells the customer what he needs, not what he wanted when he came in.

 

So... we got numbers yet? At least you apparently took the advice of all these members who, and I quote, "jumped all over" you.
Funny since we all 'have blinders on'. I'd just like to see some time slips or dyno slips to see how close you actually came to those stated goals. Curiosity really.

 

since u guys are talking about cams i was wondering if u could point me in right direction with my car
i have a 89 with original 350 l98 engine i have to rebuild lower end and thought it would be a good time to put in a cam
i have some up grades like slp runners 24lbs injectors bbk 52mm throttle body adjustable regulator granatelli mass air flow sensor flowtech shorty headers with y pipe 3 inch back single echaust no cat mallory distributor and mallory ignition box with stock heads and stock computer would like to upgrade cam and would love some ideas on what to put in!!! my main consern is dealing with computer problems after installing cam! lower end will probably be minor rebuild bearings and rings possible pistons if anyone has any suggestions please advise me on what to do

 

Uh, I just can't resist jumping in here for just a thought or two.... Granted, this isn't actually cam advice.

I definately know where a person is coming from when they say that they just don't have a lot of money for hot rod parts and want to use what they have on hand on the cheap for a few extra thrills.

But on the other hand, when you set a specific performance goal, I get pleasure in using my head and researching what might achieve my goals and stay reasonably well within my budget.
So I will watch the local and national markets closely for something that will work for me. Sometimes this just involves dumb luck, and at other times research and negotiating skills come in handy. Don't be afraid to make offers on stuff! Not too long ago I scored a 1976 van with a decent running 400 for $150. I removed the engine (at a home where I rent) and sold parts and the tires off the van and scrapped the remainder of the body and actually made my $150 back, made about $300 off the deal, and got the 400 too. It took me nearly 3 weeks to close that deal but it was well worth it! Later, I found a guy that paid somebody waaay too much money to put some other kind of heads and do other work on his fairly new crate engine. I ended up getting his Vortec heads for $150! Another time I picked up a set of good 305 Vortecs for $100, so you can find decent stuff without breaking the bank!

It's interesting and fun just getting out there in other people's shops and garages to see what they are doing and to just BS about cars and engines. Even if they don't take your offer, if you do it and handle yourself in a pleasant manner you can often learn a thing or two from the experience. Either about life and bargaining and trading, or about engines and cars. It's a shame that this is getting to be a little bit of a lost art, but there are still people doing cool things out there!