You hear a lot about running cam only on stock heads, but very rarely about heads only on stock cam. I have heard of a few instances and was pretty impressed with the results.

Pretty much what could I expect from bolt ons only with a set of ported LS6 or LS2 heads?

Would there be benefits to milling them to up the CR a tad?

Would you not touch the limiter since it would still be a stock cam?

What would be required tuning wise?

Any results out there with a similar set-up? Thanks!

 

heads only? why go that far into the engine and do 1/2 of it? do both, the factory cams leave alot to be desired for performance. The cam by itself will have a bigger return for the $ - answering your questions heads would probably add 20hp at best with stock cam and as much as 35hp with a good cam.Raising the compression would be relative to the amount increased-why not do a ported set of 5.3s? leave rev limiter alone with a stock cam since your not needing more rpm and the springs are stock, I dont think tuning will help much with a stock cam. you have to keep in mind this is an air pump and all mods need to work with each other - adding headers, cam and heads would help complete the package. now with the cost of heads and the engine is that far down why not add a cam/springs too? compared to the heads its cheap and there are alot that will pass emissions and stealthy if you dont want anyone to know .... just my opinion

 

The heads I posted would be the same price as a cam swap when considering the cam, springs, pushrods, timing chain, oil pump, gasket kit.

Going that far into the engine and not doing a cam isn't really relative. The heads are right there up top and require the intake and manifolds off, neither of which come off for a cam swap. Really the only part of tearing the car down for a cam swap that the heads would do is the prep of draining fluids and maybe the valvecovers to do springs.

Also maybe you didn't notice the car this was for. Heads are MUCH easier to do on a C5 vs. F-body with them buried under the cowl. Also a cam swap is much more involved on my car with the entire steering system needing to be dropped for it. Heads and an intake are in store for my car so the heads are RIGHT there where as a cam would still require a TON more work.

Hope this helps clairfy why. I appreciate the response though!

 

I would expect you could gain 30rwhp pretty easy thanks to a little bump in compression & the extra head flow. I'd be more than happy to work you out a good deal on PRC LS6 heads if you want to do the test. A before & after dyno would help us to know the gains...

http://www.texas-speed.com/shop/item...d=649&catid=40

 

a nice small runner, high flowing , high compression head would make for an interesting build up.

would make for some nice street friendly power, and proabably gobs of torque.

 

Put a cam in it Jonny....

Even if its only a baby cam. Your going to make way more power and retain near stock driveability once tuned. Plus you know you liked how your TA sounded after you built the motor

 

I hated how my TA died every time I came to a stoplight as well considering the tune was off Does sound sweet, but stock sounding with more power than one may expect is also cool! Plus a cam install on a C5 is a PITA

 

PM coming

 

Theres a LS1 GTO that runs around my town that put down ~430rwhp with the stock cam. Here is the link to his dyno run and mods.

http://www.jrracingtuning.com/Russ.html

 

I have posted on this several times and think it's a great way to go. Don't listen to guys who have the knee jerk response "just do the cam." You've got your reasons. Also, your list of cam swap vs. heads swap items/costs is important, especially on a C5. To me, the heads only deal makes sense if:
you put a ton of miles on the car as a daily driver and/or
if the shortblock has tons of miles on it.

My thinking is, to take this as far as it can go and retain 100k mile + reliability, heads, FAST intake, TB, lid, and exhaust are absolutely the way to go. Don't disturb the lower end if you don't have to. My dream combo would be the AFR 205s and the FAST 92/92. Don't listen to the guy who says a tune is worthless with the stock cam, he's misinformed. A GOOD tune regularly grabs 10-25 rwhp on stock/bolt on cars depending on how rich and off the stock tune is. That will only be more true with some good heads.

If you really wanted to go hog wild, Mamo-fy the heads, intake, sand and paint the intake black, use an 02+ LS6 cam/springs, get a good tune and you have the best of all worlds. 400/400 and stock manners/MPG/reliability. Stealthy killer. I put so many miles on my car, I don't want to change springs every year, which is why the stock/LS6 cam is something I have looked into.

I think you're on the right track with looking at a good ported, small runner head to maximize the stock short with no real downside. I'm curious how the new PRC 215s would do, as well as the AFR 205s. I'm surprised more people don't go this way. Some stage 1 or 2 GTP heads would be good for this too, as Craig's approach was always velocity throughout the range.

Keep us posted.
Jason

 

This is how you do it. Though the high number was run with the belt off, like he runs at the track, so it's a tad misleading. He goes into this in the dyno section. It does prove that this is very doable on the stock cam. Imagine an LS6 cam, ported FAST, and ported AFR205s...

 

Very good insight, thanks! Not that I put a lot of miles on it or it has a lot. It has 35k miles on the car right now and I will put on a few thousand a year being it's stored for 5 months of the year. I don't really like the sewing machine noise some cam lobes create and stress on the rest of the motor. I have 2 buddies that are cammed and both have had some issues in the valvetrain. Cam lope does sound sweet though, no denying that. I just think heads only could be a pretty unique, and actually pretty smart decision for a car wanting reliability but more power.

Looking at the GTO results now! Thanks for the post!

 

No problem.

 

When i had my '99 SS M6 i had a set of stage 1 853 castings ported to see what gains
the car made with heads and headers added. Before them i already had 4.10's and a SLP loudmouth CB and MTI lid. Before the heads and headers the best E.T. i had was in the 12.7's then after the adding only the heads and FLP headers the car's best E.T. was a 12.08 @ 116mph with still using the stock '99 cam and the LS1 intake. The only tuning i had was a hypertech for the gears. So i guess the right heads can deliver gains when ported correctly.

 

With as few miles as you have and put on it...go ahead and put a cam in it!

Seriously, I would DIE to see what a ported FAST combo and ported AFR205s would do with a good tune on your stock cam. My guess is 400/400 and sound stock! Good luck!

 

i dont want to do a cam at this time for specific reasons... it's install being one. Other reasons as well.

 

My question is with 243 Ls6 heads with yellow Z06 springs and 7.4" hardend push rods will that be ok on a stock motor with 103k miles? Will those heads give any problems to my rods, pistions or anything??

 

Hmmm, I smell braggin' rights and/or trying to make a point. If you go all out in the parts and details, I bet you get over the 400/400 and sound stock. There are AFRs that pop up here and on cf.com. Keep us posted on what you do!

 

nah, nothing like that. Kind of a personal reason I'd rather not get into, haha. Waiting to hear from Jason at TSP. Thinking maybe he can get me in with all the stuff I need

 

Good to see other people considering this. I've only seen one dyno result of a heads only car and that's the GTO that's been posted. Stock or better gas mileage, easy on the valvetrain, stock sound, and 380+rwhp sounds MUCH better than a cam only swap and I'll definitely be going this route. Wish I would've gotten in touch with Jason first , good luck with the swap and post up the results!