Thanks guys. I suppose I need to measure the chamber volumes and see if the difference is likely to drop the CR too much. Luckily I have both types of head on the bench, so that shouldn't be too difficult. Sounds like the petrol should be ok (the guy at Puma racing reckons so too), but I seem to remember the ignition timing being critical to avoid pinking, when unleaded was first introduced.
Like most things I do, this is on a limited budget, with the parts having come from various job lots, so the jury is out on whether to do the head. The exhaust is on already and made a noticeable difference to the top end and I'll probably stick the cam in the standard head to see what happens, just because it's quick and easy. May do the carb if I get time, although my green 2+2 had one of those fitted and didn't seem much faster. I'm a bit wary of getting involved in too much work, when the engine runs well at the moment, the power increase would be modest and I could get hold of a Fiesta Turbo lump for the cost of a good bottom end rebuild. I think I'll stick to sub-200bhp for the moment, thanks, Jim! Now, if anyone knows of a complete Fiesta Turbo for breaking at a sensible price, then I do have a space in the corner of the yard....! Budget of £600-700?? Don't tell the wife...! Cheers, Dave. On Jun 13, 10:41 pm, Jim Hearne <[email protected]> wrote: > Dave @ pumaracing did the cylinder head on my ZVH, it makes 260bhp on > 10psi boost so i'd certainly agree with him knowing his CVH's. > > Jim > > On 13/06/2011 21:16, Robert Craig wrote: > > > > > > > > > Have a look at this site - its very informative. > > >http://www.pumaracing.co.uk/CVH.htm > > > Bob Craig (Q2-267) > > ----- Original Message ----- From: "Robert Craig" > > <[email protected]> > > To: <[email protected]> > > Sent: Monday, June 13, 2011 8:30 PM > > Subject: Re: [Quantum Owners] Hemi Heads > > > Hi Dave, > > I ran a Hemi head on my XR2 engine and now have a Mk3 > > escort > > engine with the same head ( this engine had a lean burn on it when I > > bought > > > it)- both with no problems. I have a Kent CVH22 high lift cam and run > > unleaded (I prefer super but it runs fine on 95). I have twin Weber DCNFs > > but the DFT is the next best thing. Ford originally recomended filling > > with > > > leaded fuel every 4th fill. my car was built in 96 and has covered over > > 30,000 miles running on unleaded and with the exception of grinding in > > the > > valves when I changed the engine (only because the head was off anyway), > > there have been no concerns. > > > hope this helps. > > > Bob Craig (Q2-267) > > > ----- Original Message ----- From: "Dave the Subbie" > > <[email protected]> > > To: "Quantum Owners Group" <[email protected]> > > Sent: Monday, June 13, 2011 7:43 PM > > Subject: [Quantum Owners] Hemi Heads > > > Hi All, > > > I wondered if anyone could give me some advice. > > > I've come across some "go-faster" bits (fast road cam, 32/34 DFT > > Weber, K&N and 2" Ashley exhaust) for my 2+2, and they include a > > 'hemi' head from one of the early 1600 CVH engines. > > > I'm wondering whether to fit it to my late cvh, but I'm not sure on a > > couple of points, which is where I need some advice: > > > 1) Will it fit straight onto the later engine, in place of the "lean > > burn" head? > > 2) Will the compression ratio be OK with the later block and pistons? > > 3) Will it still run on 95 RON unleaded petrol? > > > The Burtons website recommends the earlier head, and it makes sense to > > add it whilst I'm messing about, but I don't really want to get > > involved with rebuilding the bottom end if I don't need to, and I > > don't really want the hassle of lead replacement supplements and high- > > octane petrol. > > > I know it's a fairly common mod and so I wondered if anyone could help > > me out with some answers to my questions. > > > Thanks, > > > Dave -- You received this message because you are subscribed to the Google Groups "Quantum Owners Group" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/quantumowners?hl=en IMPORTANT NOTE: All information presented herewith is provided on an "As Is" basis, without warranty or the implication thereof. Neither the Quantum Owners Club nor the individuals associated with the Quantum Owners Club or in the preparation of the above information shall have any liability to any person or entity with respect to liability, loss, or damage caused or alleged to be caused directly or indirectly by the instructions contained within this or related message(s).
