I am in the process of detuning my 383.
am running a GMPP 847 cam with ported Lt4 heads and Lt's
I want a good streetable engine with tons of torque, no bucking and surging while running closed loop capable of revving up to 5800.
I have a Comp Cams 503 cam (224/230 @112) under my workbench and was thinking of installing it.
Can somebody running this combo or a similar one comment if this would be a wise choice or should I go even smaller, maybe a hotcam to make sure the engine runs smooth in CL?
Any thoughts wellcome.

 

You say your 847 runs smooth an doesnt buck, but you are worried about running a much smaller cam so it doesnt buck? I dont understand why you would want to do this if your current ste-up isnt bucking. And hotcam/503 dont buck much in a 350, so most likely it wont buck in your 383.

 

Hello there

You can see my setup in my sig. Now I'm swapping to 214/224 cam to get rid of surging, bucking, bad MPG, bad exhaust smell..... (You got A4 trans so your bucking issue is not big as mine because of the torque converter)

If you want smooth idle you should look for around -7, -10 overlap. I'm tired of dealing with big cam issues. With my new cam, I believe I will rev the engine up to 6000 max. Or maybe less than that cause its a 383cid.

 

I think the 847 is bucking and he wants to go smaller. IMHO if you are not happy with the 847 you need a better tune. I have had that cam run like stock in 355 cars.

That being said the 503 will be milder, I think you will make almost identical torque, but fall off sooner. The 847 is no slug down low, I have had two motors with very flat torque curves out of it.

Is there a reason you don't want to go past 5800? I was spinning to @ 7k on a 357 with the 847 and it was very happy. In a 383 I would figure 6500 would be plenty high.

 

My setup runs really smooth with the 847. I dont have any bucking. I run a 4L60E built tranny. But I run open loop full time with fat A/F ratios. The reason for detuning is to be able to drive it more like a DD.

I am building a second car,this time a high compression 396 with LE3 heads and LE3.2 cam.
I see no reason to have two race oriented vehicles.
The 383/847 is undergoing a full street M6 conversion.

 

I remember several of your posts complaining about the bucking while driving in the city at low RPM. You always ran CL, right?
That is precisely what I want to avoid and be able to run closed loop in order to have better fuel economy as a DD. I am on the same boat on that one.
What made you choose that particular cam? It is even smaller than the Hotcam.

 

If you are set on closed loop, i guess the question is, how much bucking is acceptable? Do you want it like stock with no issues ever? Or is the occasional problem ok.

I have a 210/224 on a 112 lsa in my 355, running a CL tune. 95% of the time its fine, but even with this mild of a cam i'll get really bad bucking under certain conditions (at low speeds like in stop and go traffic). Any sort of perfomance cam is probably going to give you a few problems.

It would be interesting to see someone do a stock cam with a 383, I havent heard of that yet. CL would work much better at low rpms with as little overlap as there is. Then again maybe you could get a custom cam with a little more duration and a much wider lsa.

 

Yes I always run in CL.
I made a big research and finally decided to go with this cam. (214/224 114lsa) It has -9* overlap so the idle will be around 850rpm, not 1000 If you want kinda stock idle you should get a cam which has around -7 , -10 as I said before. The tricky point is keep the lifts as high as possible to use your heads.

BTW I'm going to be FI. So I really don't care how much hp I will lose after the cam swap. I will get enough hp after my procharger installed. This engine includes 1500$ Lunati Crank, 1300$ Oliver Billet Rods, and I didn't build this engine to use it for ~400rwhp, or It is a big waste of money right?

 

With my CC 501, I am very happy with its drivability. Acts essentially stock with just a little meaner growl. HP flattens out at 54-5600 RPM.

 

Thanks for your comments, 95Blackhawk. That is what I am wanting to listen to.
The 501 is a 212/218 @ 112 cam.
Just NO is going with the 214/224 @ 114 for a FI application.
I have several cams under my workbench and want to make the best choice possible.

The smallest I have is the Hotcam 219/228 @ 112
Then I also have the 503 wich is 224/230 @ 112
I also have access to a blower cam 224/236 @ 114

For now the Hotcam seems like the best choice for my goals of a CL running, no bucking, 100% streetable 383. I am sure there must be some 383 LT1's running the Hotcam. Please come forward and comment.

 

If you want great street manners without Forced Induction, you should definitely go with LPE 211/219 112lsa !! I strongly suggest this cam. If you search here you can find people use this cam.

 

What is the lift of that 501 cam? I think you wasted lots of HP because of the low lift. Because you heads are ported. You know lift doesnt effect the drivability.

 

The LPE 211/219 and crane 227 are both torque monsters in a 383 - and a 350 for that matter.

I would go for the crane 227 if your LT4s are well ported - a 383 will eat up some of the lope and a good tune will have very little bucking. Would be a stoplight-to-stoplight killer.

 

I did lots of research but never heard about this. There are other options out there and I don't doubt there are better choices than what I went with but it does work for me. Sure I wish I could have had 10 extra TQ in the midrange. Is it there with no loss to the low end?