If you could only have one, which would it be? What one will give the best performance?

 

I'd say heads... but i hope no one would be crazy enough to go the route of doing a head swap without doing the cam at the same time :nono:

 

If you don't do heads, intake and cam it will never run well. Save and do it all at once.
If you must do it in steps, pick a goal and work towards it. Plan, Plan and Plan some more!

 

Jay all due respect, you don't understand! You have to do both, or save your money. If you make the heads breath you have to cam for the heads, if you change the cam what you gonna do with the flow? It's all a system, you can get a little from either, but better to match the setup.

Figure out what you want, save up and do it right. That's my advice.

 

Somebody has to say CAM and I guess I will.

Agreed its all a system and needs to work together. But to answer the question, and to only have one mod, the CAM in my opinion offers the best improvement in performance for the lowest cost.

The stock CAM in an L98 could use a lot of improvement, take a look at the numbers. While the heads aren't the best, these same castings as used on the ZZ4 make 355hp, quite a jump from the 250hp on a stock L98. All things being equal, I wouldn't worry about the heads until you can get another 100hp out of them.

Let the discussion begin :D

 

1.) He has an LT1?
2.) L98 wont run much better with just a cam, it has a breathing problem in the intake system.
3.) D Port L98 heads are pretty good, so I agree with that to a point.
4.) How do you campare a ZZ4 with short runner carb setup to a TPI setup?
You want 100 HP you better do intake, cam, heads, exhaust and tuning. That is the package.

 

According to John Lingenfelter...

Good heads can make power with a marginal cam, but a good cam will struggle with marginal heads (this is a paraphrase, but you get the gist.)

take it or leave it

You have to determine where your components fall .


[Modified by BobMachus, 7:15 PM 1/2/2002]

 

Well the question he posed was, if only one, heads or CAM now lets go from there.

1. Don't know if he has LT1 or not - good question.
2. Agreed breathing problem on the intake. The biggest restrictions are the base, runners and plenum in that order, not the heads. Putting bigger heads under those stock pieces is worthless.
3. Agree
4. I'm not comparing the intake of the ZZ4 and the TPI. I'm using the ZZ4 to demostrate that the heads (because the same heads are used in both cases) are not the biggest restriction to power on the L98. What I'm saying is that the heads are capable of flowing enough to produce over 100hp more than they currently do. Therefore the restrictions lie elsewhere.

A package approach is the best, but the question was only one mod, and for the money spend and power in return it has to be the cam.

 

His profile says he's got a 94... so as long as we're assuming he's talking about his vette... he's got an LT-1.

 

Cam only seems like an expensive mod on L98 or LT1. How much you think you can get $ / HP? Then how much do you think you can get for a package focused upon the gain the OWNER WANTS for $/ HP? See that's that other problem, how much does the owner want, and when does he want to get there? There is no magic bullet on engine work, not K&N filter, not cam, not heads, not airfoil, not intake, not programmers; It's the package properly designed to meet the owners desires and budget. It also helps when the owner knows exactly where he / she want's to go and how much they want to spend.

Pete

 

Well...for a $300 cam I am sure I can get over 40-50 more ponies...while that $1500 set of heads will gain me a cool 20-30 HP.

You do the math.

BTW: The best way is a cam/head package. :chevy

 

:yesnod: That was the point I was trying to make.

 

I'm not going to argue. Do what you like. :D

 

Though an LT1 is a different animal, an L98 gained:
30hp-from TPIS SuperProfile cam @106deg, before intake & exhaust mods
28hp-from TPIS Stage II heads, after intake & exhaust mods.

Looks like the cam has the edge, especially since other major air flow enhancements had not been done yet.

 

OK 65Z01, I won't argue but how about a small wager?

I'll present this wager:

I'll go to Cartek in NJ and I'll pay to have that cam TPIS SuperProfile cam @106deg installed on my totally stock L98.

I will pay for dyno before and after testing (compensated for testing differences of course).

You come fly out and witness dyno's.

If I make 30 HP or more, I will give you the cost of the cam, installation, and airfare; a huge profit for you.

If I make less then 30 HP, you pay for cam, installation dynos and your airfare.

If you would care to make similar bets involing other mods, I will entertain them as well.

As part of this bet we will both place the money in a secure location (up front), such as a non-involved forum member (I would suggest Purp, but he would have to accept). If a forum member agreeable to both of us could not be choosen, then I could arrange for a 3rd party account to be set up for which the looser would pay the costs, usually 1% plus legal fees.

You in?

Pete

 

You're right, I don't know what I'm talking about. Thanks for the replies :chevy

 

if i had to do one at a time, id do the heads. I mean, maybe your heads are clogged up with carbon and gunk and the cleanup and better compression will help the engine, i think it would be better for the motor if you did the heads.

 

If the other guy ends up flying out there...send him here next when I get my car, so I can put a cam in. :yesnod:

 

I see a whole bunch of stuff here from people who have obviously never tried it. True an exteremly aggresive cam can have a very hard time with stock heads, but a mild cam can do very well. I'll use myself as an example, I had money to spend on the car and opted to do a cam. I couldn't afford heads at the time and still have stock heads. My reasoning is that I can do heads later without having to take the whole front end off the motor. I used the LT4 Hot Cam, very mild by performance standards. My only other "performance" mod at the time was an electric water pump. I picked up 44 horsepower. Now that's a serious kick in the pants. I can outrun probably 99 percent of the "sports cars" around here. I've even had C5's try me. They were in for a nasty little shock. I won't say I won, but I certainly didn't lose as bad as they thought I would. BTW, that's on a completely stock exhaust system, still 100% emissions legal.

Later I can always buy a set of heads, but I did headers first. Why did I do that? Well I was talking to the owner of Total Engine Airflow, they are awesome, they have one of like 3 five angle CNC machines in the country. Anyway, I asked him which he would do first, heads or headers. (I already had the cam) He said headers, as it was a set of his heads would choke behind the stock manifolds and wouldn't see any decent gain, he's dyno proven it many times. I took his advice and installed headers. That's another kick in the pants, I'm gonna dyno it Saturday and see what that did for me, but it feels like at least another 20.

So by all means go with the cam first. I'd love to see you pick up 44 hp out of a set of heads on an otherwise stock motor. Also I dare you to do it for the same $450 the hot cam kit will cost you. Sure heads are needed to get peak performance, but they really need a cam, and headers. For best performance you need them all, but if you go with the cam you are working from the inside out. Once you get the motor put back together when the cam you don't have to take it apart again. If you are good you can install a set of heads in a day, later down the road.

Personally I plan on eventually buying a good set of used stock heads for cheap, then having my work done to them. Then I'll install them whenever I feel like it, with very little downtime. By that point I won't be choked by my exhaust and cam. The only thing left would be the intake, which there just isn't much you can do on an LT1 but smooth it up a little.

Flame me all you want guys, you can get lingenfelter to flame me as well, but you can't argue with my dyno results.

 

Woa Pete, such a deal. But the air fair isn't much of a "prize" since I can drive to Cartek in about 1/2hr or so! I'm just north of Bergen Co, near the TZ bridge.

Anyway, remember I said no intake or exhaust work, but I didn't say bone stock; some other work had been done (you've got mail). Those numbers were obtained from trap speeds on a modified L98 in a '90 Vette 6-speed, so that means #113 heads. I'm using an old CF article "HP Conspiracy" as a guide for enhancements and source of data.

If you want to bet, I'll be glad to meet up at Raceway Park this Spring on Gampler's Night.