Misfiring after cam shaft installation - suggestions?

[Pete]

^ This. If DHM was getting them from ARP they exist in the ARP catalogue. DHM didn't have exclusive rights to this stuff, you just have to find the part number. Same as their high compression pistions. IIRC they said Weisco was making them for them. I highly doubt that was on an excuslive contract either.

That said, any place that carries ARP hardware will be able to order them in for you, once you have the number.

http://arp-bolts.com/kits/Make.php?_Make=402&_EngModelID=*

The 2.3, 2.7 and 3.5 are listed. I'm sure the 1.6 just hasn't made it onto their website yet.

DHM didn't have high compression pistons. They milled the head and block mating surfaces to increase the compression ratio. Weisco was there gen 1 pistons as well.

 

[thePete]

Well that's just not a great idea, but I didn't realize that. I just made the silly assumption they were doing it right.

Sent from my SM-G930W8 using Tapatalk

 

[Pete]

Well that's just not a great idea, but I didn't realize that. I just made the silly assumption they were doing it right.

Sent from my SM-G930W8 using Tapatalk

I've personally done it before on my Porsche 944 and had no I'll effects.

 

[thePete]

Lots of people do lots of stuff they shouldn't and get away with it. Generally speaking it is a bad idea to machine for increased compression ratio on an ohc engine for a variety of reasons. I assumed they went down the road of new pistons, that's all.

Sent from my SM-G930W8 using Tapatalk

 

[Pete]

Lots of people do lots of stuff they shouldn't and get away with it. Generally speaking it is a bad idea to machine for increased compression ratio on an ohc engine for a variety of reasons. I assumed they went down the road of new pistons, that's all.

Sent from my SM-G930W8 using Tapatalk

I would say it's more so for getting a nice flat mating surface for both areas. Not much has to be taken off to bump compression. If I remember when I did it with my Porsche (I had a timing belt failure and bought a used head) the machine shop removed .040" in total. Which gave me the fact surface I needed and jumped the compression up a whole point.

 

[mercdank]

Any update?

Car is up and running and on the 9th revision with Adam. Car runs like a beast, I am loving it.

 

[DvC]

Car is up and running and on the 9th revision with Adam. Car runs like a beast, I am loving it.

What ended job the issue?

 

[mercdank]

The original misfiring was due to an issue with the spark plug/coil. After we sorted that out we had more issues with the fueling especially getting the car to idle well and to not stall out. I don't think it was anything mechanical after the spark plug/coil thing got sorted, it was just a matter of getting the tune right, which Adam has 100% done. Car runs great I love it.

 

[thePete]

Interested in some dyno sheets to compare to stock cams. Any video clips?

Sent from my SM-G930W8 using Tapatalk

 

[mercdank]

No not yet. I want to wait until the tune is 100% dialed in with Adam before I hit the dyno. I will definitely post a video.

 

[Spaceman_Spiff]

So what was the fix for the cam not spinning? Is it bolted on and it came loose or what?

 

[mercdank]

Yea, bolt failure. We got newer slightly longer bolts and that did the trick.

 

[wraith]

Sorry I'm not as familiar with the parts...

The shorter bolt that failed and you replaced, is that a faulty part on the original motor in your car or the part that came with your upgraded camshaft?

 

[Intuit]

Bolt probably "failure", or backed out in response to pistons meeting valves... or even valves meeting valves.
http://www.enginebuildermag.com/2013/02/top-reasons-and-causes-for-camshaft-failure/
Frankly I'm somewhat amazed at the number of ways one can screw-up a cam install on an engine that is thoroughly of interference design.

 

[draxxus131]

Did you finally have the ECU re-tuned?

Sent from my XT1650 using Tapatalk

 

[A7xogg]

any update?

 

[Thedoctor]

Update?

 

[Klink]

Any updates on sound? hp gains? looking at getting piper stage 2 or 3 soon.

 

[Xaendeau]

Any updates on sound? hp gains? looking at getting piper stage 2 or 3 soon.

I'd be curious to see what happens with the cams too.

 

[Mortont1]

He posted a set of stage three cams for sale recently on a Facebook page. I messaged him about updating the thread, he’s just to busy right now.