Finished rebuilding my engine after a valve head came off and punched a hole in a piston, it got new piston and rod, shells, seals, recon head with new valves and a full piper 285 cam kit. Been running it this week gradually building up the revs, everything seems to be fine.

Until i get just over 5k rpm, it seems to hit a soft limiter? It went past this before on standard build (very rarely though). It's absolutely fine up until this point using varying throttle loads, but over it whether light or wide open throttle it seems unhappy.

I thought it'd be a coil pack but it was fine at ford fair on track so it shouldn't be any different now, maybe valve float but the springs should be correct since they came brand new in the kit from Piper?!

Engine is original 1.6 efi in xr3i, cam was run in according to Piper's instructions. PLENTY of millers assembly lube was used and i followed the Haynes CVH rebuilding book.

I'm lost for a cause at the moment, anyone got any ideas?

 

And to add, oil pump was given the all clear by engine reconditioner who did the honing, and i checked all clearances were in spec during rebuild.

BTW, if anyone has any AFR equipment in the Preston/Blackpool/North West areas then i'll gladly cross your palm with some beer tokens to get it checked out.

I spent more than i budgeted rebuilding the engine so if i can work the niggles out myself it saves the time and expense of taking it to 'an expert'.

 

Early evening bump.

 

Probably one for the more technical on PF i know but it's a Ford and one that's still fighting to keep going so if i could get some advice or help that'd be great!

 

I had the same problem whit the full piper 285 cam kit on my Mk3 Cab.
whit properly set-up vernier pulley and without it wouldn't pass 5500RPM

This morning i decided to install my original Cam.
now it makes 7000RPM and more (no limiter)

Does anyone have any idea what the problem is here ?

Greets, Thro
(belgium)

 

Did you put the original valve springs back in with the original cam?

My problem is valve bounce, the valve springs Piper sent out with the kit must not be strong enough. I'll be getting back in touch with them Monday to see what the set they're measuring come out at. If they still aren't strong enough i'll have to sort something out with them.

I've been advised standard RS turbo valve springs will cure this, but spoke with Piper first since the kit supplied obviously isn't correctly spec'd.

Another option advised is the Newman 190lb single valve springs, these are Ł48 for a set of 8, and should also cure the valve bounce. If Piper don't co-operate/supply correct springs i'll be using the Newman ones and i'll let you know if it cures it. I should know by the end of this week.

 

I'm still runing the piper springs and hydraulic followers
The only thing i did was change the camshaft back to the original

it seems to be reving fine till 7000RPM

i was thinking its the camshaft that is causing the problem,
when i compare the piper and my original cam the lobs on the original cam are 1mm higher, is that normal ?


Greets, Thro
(Belgium)

 

If thats the case i end up with the i'll be taking my cam to Piper and hitting every employee i've spoken to around the head with it. Are the bases of the lobes still the same diameter?

I can't see the fast road cam having less lift than standard :S

 

i have no idea what diameter of the bases of the lobes was when it was new,
so i don't know if that has changed.

I'm curious if different springs will change anything though.