Advice on cam selection

[Tar2001]

So can anyone give me a clue about what torque/hp curves to expect?

[Cheromaniac]

By the way, Dr. Dino i sent you a PM.

Got it and sent you a reply. I used the early HO stock cam and with a 9.25:1 SCR, ported head (stock valves), '01 XJ intake manifold, and full external bolt-ons (cold air intake, 65mm TB, Borla header, 2.5" exhaust), these are my HP/TQ curves:

[Tar2001]

By the way, Dr. Dino i sent you a PM.

Got it and sent you a reply.

Thanks, but i didnt receive it.

[Cheromaniac]

Just sent you another one Tarek so hope you get it this time.

[Tar2001]

Got it, i really appreciate.

[Tar2001]

4.7 stroker in final stages, assembly this week hopefully. Machining is done and all parts are ready, but still hesitating about cam choice.

Here's my specs, kb944 pistons with long rods, 55cc comb chambers.

I am considering using the 96+ stock cam with 4 degrees retard, which will give a DCR of 8.0.

I am just not so sure where the peak hp would fall, i hope not well below 4500. And hope it would still have more low end torque than a comp 231.

What do u guys think?

I still have a comp 231 in good shape from my previous stroker. The valvetrain was a bit noisy, some hesitation off idle and stalling sometimes, didnt degree that cam and i dnt think i have this option also with this build.

I also have a 91-95 stock cam (which seems to be in a modest condition) and a renix stock cam. I am not sure they are the same. I read that the renix is straight up while while the later ones have 8 deg of retard. True??

Any advice before i go for it

[SilverXJ]

A noisy valve train is normal with the Comp Cams. Hesitation and stalling is not. Either it wasn't indexed correctly or you have some other issue like a faulty sensor. Itw ould be a good idea to degree the cam in.

[doc65]

I'm not trying to hijack this thread, but I have a similar question regarding cam selection. I have a Sroker that is still working on being broken in. It was originally a kit form Accurate Power, I CC'd the chambers & cylinders with pistons installed, I figure I have about 9.26/8.0 SCR/DCR, and it is a 68-231-4 cam, I find that the idle is a bit rough when sitting at a stop light in gear(Automatic/42RE in a ZJ) not beyond what I can live with, but not great(my stock 98 XJ is MUCH smoother, as were several others I've had over the years). I'm wondering if anyone has thoughts on how much of this is caused by the cam?

I'm also starting to acquire parts for another engine for a different jeep, so I'm looking at which cam is my best choice, the target specs are 9.32scr 8.14 dcr(calculated with the same 68-231-4) .055 quench, short rods with 677's dished to 25 cc & block decked to get to those numbers. My personal choice is to have it be smoother & quiter(valvetrain & pistons) this time around even if it does cost a couple HP or Ft/lb. Any suggestions? Block donor(96 ZJ that got the first stroker) was actually in pretty good shape especially for 192K, but broke a piston skirt on #1 the cam was puled with the lifters kept in order & actually still looks pretty good, so I'm considering re-use, I really wish someone made a roller cam that would live at least medium life, with out requiring new dist. gear every couple K etchttp://www.jeepstrokers.com/forum/posting.php? ... f=5&t=2547#.
Doc

[Brian E]

I will throw a question in and hope I am not repeating what some one asked. These engines with OBDII and never seam to freak out a bit with 110-111 Lobe Separation, but I see you guys going back and forth between the 231 and the 232. I have the 235 with 111 LS and it runs like crap during warm up an hot start up trying to figure what it wants to do and is very intermittent. Wouldn't the same hold true for the 231? I am about to switch to the 232 and hope for mileage and a smother engine. Have a lot of people on here tried the 231 with 98 and up or is this mostly related to earlier engines?

Thanks, hope this too was not considered a highjack, I am hoping it leads to more info for all.

[Brian E]

I will throw a question in and hope I am not repeating what some one asked. These engines with OBDII seem to freak out a bit with 110-111 Lobe Separation, but I see you guys going back and forth between the 231 and the 232. I have the 235 with 111 Lobe Seperation and it runs like crap during warm up an hot start up trying to figure what it wants to do and is very intermittent. Wouldn't the same hold true for the 231? I am about to switch to the 232 and hope for mileage and a smother engine. Have a lot of people on here tried the 231 with 98 and up or is this mostly related to earlier engines?

Thanks, hope this too was not considered a highjack, I am hoping it leads to more info for all.

Corrected in case my other one makes no sense:)

[SilverXJ]

I've had the 231 and 232 on my 2000 XJ and never had a problem with them. I have the Hesco RVOB installed 4* advance and it has problems on cold start. Well, I'm not 100% sure its the cam, but I have been trying to figure out what is causing it.

[Brian E]

I contacted 505 today and gave them my engine specs and gearing. I asked them for a cam recommendation and they recommended their Stage 2 cam. What I found interesting over all other brand is their intake lift is higher than their exhaust lift on all their cams including this one. They also seem to use 114 lobe separation on all of their cams. Anyone know what the factory lobe separation is on most 98 and up 4.0 cams? I really Eye balled the 505 roller cam and the price was not so much an issue as I just spent so much setting up my springs and retainers for my comp 235-4. I would have to start all over again.

Comp cams seem to always be around 18-20 thousandths lift more on exhaust than intake.
Crane leans the same way as does Lunati.

[SilverXJ]

Most aftermarket dual pattern cams have more exhaust lift than intake. Its interesting that 505 has the opposite.

What exactly is yours doing on cold start?

[Brian E]

It will do it on hot start too but most of the time cold is the worst. Starts easy drives to the end of the block easy. Pull into traffic and 90 % of the time I pull off tot he side for a moment and wait for the engine to re-guess what its doing then take off fine. It also has a strange intermittent surge under heavy acceleration. I thought it was a fuel issue but I placed a gauge on the windshield and drove it for weeks and no pressure changes, about 58 continues. I have played with timing, distributor and crank pickup, I check for vacuum and new oxygen sensors. No codes and when its hot it feels like vapor lock but the fuel pressure never dips and it can do it even when its not that hot, wide open throttle I can break axles:) Lee at Hesco thinks I am not going to get it to run right with a 111 lobe separation as did the Comp Cam tech on line. But I saw Golen Engines I beleive using this cam in their Stroker add so I thought, what the hell. My bad, I had the 232-4 in my previous engine build and it ran great, when the lobes rounded off I thought I would try something different. 505 looks good Stage 2.

[SilverXJ]

Mine happens for about 1/2 a minute it goes lean, sounds horrible and is generally undriveable. The colder it gets the worse it gets. Everything else checks out. After that its fine aside from a bit of a rough idle. I can work aroudn that by modifying cells in the fuel map on the AEM, but the it has a hesitation when it hits those spots while driving. The RVOB has a 110 separation. I have an Isky custom w/112 that I may consider swapping out for.