Gradually losing power....

[grif500]

"Distraught Griff owner needs help!"

Ok, bit o.t.t., but any help or advice would be appreciated.

Basically at the end of last year I had my Cam replaced, along with the various components that go with it (went for solid rockers and the adjustable push rods (think thats what they're called ) as the cause of my cam failure was a loose rocker pad) and initially all was good
However, over the last month or so I've noticed that the car seems to be losing power above 3/4k rpm, to the point where when accelerating hard in 3rd I can't keep up with other cars on the road!! The cam I had fitted wasn't standard, and had a higher lift which meant part of the block had to be machined away to accomodate it. I've been told that these cams can alter the cars performance, but I thought it was low down grunt that went, not higher up?? The car also has straight through pipes, and has been de-catted, so could this be a back pressure issue??

So, has anyone on here experienced similar problems, or can explain what is going on with my car?

Edited to add.... thanks
Karl
as you can tell, I'm not techinically minded when it comes to cars, so sorry if the above doesn't make sense!

>> Edited by grif500 on Wednesday 1st February 10:17

[Wildfire]

Sorry, not an expert on the RV8s, but power loss over 3K shouldn't be to do with the cam. You are correct in thinking that a high lift cam ususally results in torqe/power loss at lower revs and gains in the mid - top. Sounds like somthing else has gone strange in the engine. Have you checked for "mayo" in the oil filler car and other problems?

[grif500]

Wildfire said:

... Have you checked for "mayo" in the oil filler car and other problems?

Yeah, oil is fine, I check it at least weekly and top up where necessary. It's still nice and clear, and no muck around filer cap, also no unusual noises coming from engine..

Thanks though, keep the pointers coming

Karl

[crackedfinger]

Blocked Air filter? Happened to one of my cars once, filter box blocked by straw.

>> Edited by crackedfinger on Wednesday 1st February 12:06

[HarryW]

OK would normally advocate going over what you'd last done before it went wrong, as its the cam we'll skip it for a bit .

First and simplist thing to check is the intake hoses and filter. If you have the original flexible hoses be careful to check that the inner liner (it's double skinned) is not 'balloning' blocking the intake at high loads i.e. there should be no nicks or cuts on the inside of it.

[grif500]

HarryW said:

OK would normally advocate going over what you'd last done before it went wrong, as its the cam we'll skip it for a bit .

Fair enough, to be honest I can't really compare pre and post performance for the cam replacement. It was one of the first things I did to the car when I got it, not for a preformance mod but because the existing one was knackered!

crackedfinger said:

Blocked Air filter? Happened to one of my cars once, filter box blocked by straw

HarryW said:

First and simplist thing to check is the intake hoses and filter. If you have the original flexible hoses be careful to check that the inner liner (it's double skinned) is not 'balloning' blocking the intake at high loads i.e. there should be no nicks or cuts on the inside of it.

So would I be right in thinking you mean the flexible hose that runs from the front of the car and down the passenger side of the engine? If so, then this could well be an issue, as it's seen better days. It seems to get crushed every time I close the bonnet. Is there a solid (or solider sp?) version of this to prevent this from happening? Regarding the air filter, does anyone know the part number of this? I've looking through "the Bible" and can't find any reference to it.

Thanks again!
Karl

[grif500]

Sorry, forget that about the air filter parts, need to learn to look before I type!!

Induction kit on order from ACT, hopefully sort some of my problems out. I've also got my eyes on their carbon fibre plenum kit, is this a DIY mod or would I be best getting "those in the know" to do it for me?

Cheers