whats up guys, i just built a b18c1. i used an ls crank with p30's the head has been shaved and thin headgasket. I should be looking at just under 12:1 compression. I'm using s2p2 cams, +5+1 cam degree settings....

Now for the problem. The car hits a rev limit at what ever vtec is set at. If vtec is set to cross over at 5500 it will rev limit there, if its set to 6500 it will rev limit there. If i partial throttle or disable vtec the car revs all the way to 8k no problem. I've done a million test, the car can mechanically hit vtec, i engaged at 5k at a dead stop by connect 12v to the solenoid and watched the oil pressure gauge (hooked up to the 10mm port on front of head) go from 0psi to 70psi after the 12v was given to the solenoid. i have around the same oil pressure when hooked up to the oil pressure switch port.

I have put my hondata in another car and it pops vtec so the computer is ruled out. Ive traced my wiring and its all done 100% soldered everything, its all good. All the sensors are reading properly and my tuner says judging by the data logs and how smooth the curve is until vtec that all sensors are good.


We have now come to the conclusion that my cams are overkill for the build. the duration on the cam is ment for higher compression and the combo is not working, He was saying something about the overlap. He suggests trying a smaller cam. and im thinking the same.

I have a few data logs to share and my calibration also, if anyone is skilled enough to look through and make any suggestions. i also might be able to post a video of the "Rev Limit".

what do you guys think, any ideas from the more experienced guys out there.??
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If you are running +5 on the intake cam and +1 on the exhaust, its hitting rev limit maybe because you are probably running into some valve to valve issue or piston to valve. Thats probably why it only happens in VTEC. How's the car running? No bent valves?

 

car runs great, good compression 240 across the board. no bent valves, valves would have bent when i manually engaged vtec at a standstill.

 

and im pretty sure its +5 ex +1 in

 

What plugs are you running?

 

Sounds like you are running into piston to valve conact on VTEC activation. Stop trying to get into VTEC until you solve your problem, it can be catastrophic if you don't.

You're running a shaved head with a thin head gasket, that will decrease your piston to valve clearance especially with these cams.

Pull the head off and check the pistons if there are valve imprints on them. If you are having piston to valve contact you will need to get pistons with deeper valve reliefs built in or take your pistons to a machine shop and have them machine deeper valve pockets.

 

what cam gears are you using? Some cam gears are made for 1 mark to represent 2 degrees.

 

im running obx cam gears. u guys think i should run skunk2 quick settings +3 ex -1 in... i had these cams degreed by a local machine shop, so i doubt im havings p2v but i guess anything is possible.... i did a cylinder leak down and there is less than 5% leakage all cylinders.

 

OBX cam gears?!?!?!? Get rid of that rubbish and get some accurate gears on that car. I am sure if you put a set of Skunk Pro gears on, then your problem is solved...well outside of the fact you probable bent valves already.

 

If his car runs fine on the primary lobes, how could he have possibly bent any valves? I have never seen a cylinder with a bent valve run.

 

Different set of gears isn't going to solve it. If your valves aren't bent then its probably not v2v or p2v then, especially if you already tried it at higher rpms (5500+).

 

i know you guys are helping me out, and i dont mean to be rude, but why even waste your time saying stupid ****. The car does not have bent valves. I DID CYLINDER LEAKAGE TEST WITH LESS THAN 5% LEAKAGES ACROSS THE BOARD, I DID A COMPRESSION TEST WITH 240 NO FLUCTUATION. I can understand if you dont know the answer to my problem, but dont go saying stupid ****, just shows how ignorant you truely are.


With that said, thanks to everyone with positive feedback, i talked to pherable.net they are saying my rockers might not be clearing my valve retainers.... anyone have experience with this?

I dont have much experience with LMA's, could this be the cause?

 

Since you've taken the next step to talking to a professional about the problem. I'd let John take it from there.. On the internet you're going to get alot of this and that. First off let John make sure the cams are properly degreed in, if not, at least use skunk2's quick settings..assure you, you're pro2's would not run @ +5 intake and +1 exhaust..

It sounds like a combination of tuning + some type of clearence issue in the head.. allow john to take a look at it before speculating any futher.

Do you know your V2v or P2V? at all? If not, and you are retainning stock sized valves, v2v should be fine with the quick settings, p2v should also be ok if you're using good pistons with good cut valve reliefs. Since you've already been in vtec and haven't contacted anything i'm sure you're fine.

 

Thats what i was going to suggest next, your retainer to valve seal clearance. What valvesprings and retainers are you running? Proper installed heights etc?

LMA's wouldn't affect it, they are there to absorb the VTEC pad when its not engaged.

 

thank you all m0t0r for taking the time to read my post. is john the person at phearable, not sure where they are located but im in rhode island. im using stock valves with pro series valve train. the quick settings are +3 exhaust -1 intake...correct? That was my next step... The only reason im thinking my rockers clean the retainers is because at standstill manually engaged vtec for about 2 seconds with a 12v source to the solenoid to check for oil pressure....i am 100% that vtec did lock and herd no abnormal noises, this was at 4-5k rpm.

I had a shop degree my cams but i got the motor back with no acceptable settings or clearances so i was alittle sketched out. advancing both cams gears that much i feel like might be the cause of this.

 

You could always engage vtec with air and the engine not running, then turn by hand looking for clearance issues. It's all simple troubleshooting.

John Vega a professional? Meh.

 

Tou's right, i'd check install height first.

Return the car back to shop and get some solid numbers, if they can't provide it, they need to provide you a refund of some sort for not completing the job.. John is in FL, not RI, some shops close to you that can get this done and fixed properly would be YCU underground tuning, Xenocron Tuning or IWM, or Charm City tuning.

You'll want 4 degrees of seperation between the cams. I normally like pro2's @ 0/+1 intake and +4/+5 exhaust, this is normally a good starting point for stock sized valves, with good clearence, you can move the band around on the dyno to achieve proper powerband useage..

 

i work for honda myself, so im fully capable of this work. Im going to rip the valve cover, set the cam gears to new settings and see what happens. im also going to take a video with my go pro so you can see whats happening, i wish i could upload my data logs so you could check them out quick....do you have an email adress i can send one too.

 

Be on tonight, i've reviewed your map and logs, found your problem.

Edit: Found 1 of them.. Based upon your logs, with your vtec set @ 6000, the map doesn't change over from low cam to high cam, its like the rev limit is @ your vtec.
Possible causes; Bad ecu?, wiring harness messed up? Is vtec grounded properly?

Have you tried a brand new map, and started from scratch?