Car ran good before but wanted more so I changed my cam timing with a cloyes hex adjust timing chain. Moved the 112 Texas speed ms3 cam to 108. Next I installed a set of hand ported 241 heads. Finished up with new exhaust and BMR rear suspension. Everything seems fine just doesn't have the bottom end pull or the sit u in the seat acceleration. Why? Car made 387 rwhp on dyno before changing out heads and timing chain haven't dyno end it sinse changes any help will be appreciated thanks

 

So the car just "feels" slower? I'd have it thrown back on that same dyno as before, and see what is really happening

 

you advanced the cam 4 degrees and are surprised it lost low end? wat?

 

Advancing would theoretically bring the power band down and help build more dynamic compression. So yes, I'd be surprised if he lost torque.

Of course, if the ported 241s are hogged out... then nothing is helping that.

 

I'm trying to figure out what he wants answered. A 112 MS3 is already on a 108 icl, and he took it to 104? I'm leaning more towards the hex-a-just is a huge unreliable piece of ****.

Did you degree the cam? (Assuming no)

Who ported the heads?

 

We did degree the cam. My buddy builds race engines for a living and I assume he knows how to degree it correctly. Car fires up quickly and runs very smooth. The ls1 had great bottom end torque even with 3.42's and a 3200 converter. It still runs good but just doesn't seem to pull like before down low in the rpm. Trying to figure out if the ported heads or the timing is the culprit for the loss of power. My engine builder told me I should have more power down low with the cam degreed at 108

 

MS3 is actually ground with no advance... so he went from a 112 ICL to a 108 ICL...

That's one reason they like a TON of compression if you leave it installed straight up.

 

Your builder is right in that advancing the cam should bring the power in sooner. I'm wondering if you somehow actually lost compression in this whole process

 

I stopped right there. Not all ported heads are created equal, and certainly with hand ported ones.

Who knows how big the runners and the chambers are, or if they are even equal across the board. With those randomly hogged out by some guy with a dremel, I'm not surprised your results are all over the place. You could've lost significant air velocity and compression (even with the earlier ICL) which would explain the loss in low end power.

 

Who ported the heads? Do you have any info on what was done to them?

 

Yeah people thing "ported" means "ported and better" when in reality it can mean very expensive scrap metal.

 

I've seen a guy local with a MS3 and some hand ported 243s that only made ~340rwhp and runs like a turd at the track to back it up.

I blame the heads, fairly sure his are hogged out likely destroyed all velocity they had.

 

Ok I have narrowed the problem to the ported 241 heads so if I'm pulling the motor AGAIN then should I just buy a set of 243's or 243's cnc ported like patriot performance. I would like to get to the 450 rwhp mark. I'm right under 400 rwhp now with all my mods. Is the 243's the way to go on a stock bottom ls1 with Texas speed ms3 cam?

 

I am pretty sure TSP usually pairs that cam with their stage 2.5 5.3 heads for more PTV clearance. They should also run you less than buying 243s and having them ported.

 

Travis ? If so I agree with the possible hogged out port job and losing velocity for the torque. Torque is about velocity not volume.

 

you have me worried now, if my new setup with a ms3 doesnt dyno atleast 475whp im going to be extremely dissapointed...

 

Interesting, Im on here looking for info related to 241s and the MS3 cam. I am about to do this swap on my 00 SS and I have ported 241s and a MS3 cam that I plan to put in. Afraid I may run into similar problems. The heads have been ported but look professional. idk....

 

Who did the heads?

 

I am unsure because they came with the car as extra parts. I havent found a porters stamp or anything.

 

Tried a cranking compression or leakdown test before tearing it down?

How did you conclude its the heads?

Big difference in your dyno vs expected #s.


Make sure you have some cyl pressure first