Road rally Pinto upgrade

[tom_escort_mk2]

I have an injection pinto engine running a 32/36 carb, bestek electronic ignition, Ashley 2" exhaust, Piper 285 cam and valve springs. It's running 128hp with equal torque and goes well. I use the car for road/targa rallies so I'm limited by two chokes. I'm looking at the next stage in upgrading the engine and looking for advice as to what I need to do to get closer to 140/150bhp without sacrificing the torque as it needs to accelerate from.low speeds alot. I don't know whether to focus on a great head, bottom end or the induction. Appreciate any help

[Miniliteman]

Do you now have a std injection cylinder head?
Compression ratio?

[tom_escort_mk2]

Correct, it's been rebuilt with new guides, etc. It only had a minor skim when rebuilt so it won't be far off standard compression

[Graham]

re working the head with big inlet valves and raising the compression should get to to around 140 bhp

[tom_escort_mk2]

What compression could I go to safely on standard pistons?

[Forest_rallying]

If I were you I would be very careful spending lots of money on your cylinder head just to get approx 15 bhp when you are only using a 32/36. Money might be better spent on other parts of the car and honing your driving skills to improve your times.

If you want to have your cylinder head modified then a good porting job by a Pinto specialist on std valves would be a good start if you didn't want to go to the expense of big valves. 10.3.1 would be a good starting point with a 285 degree duration cam for compression and no more than 10.5 on std pistons. A 30 thou MLS head gasket might just lift your compression high enough if your head has already had a slight skim aswell as improving squish.

[Graham]

10.25 will be about right, thats a whole ratio up on standard, standard cast pistons will take more, you can go to about 10.5, perhaps even a little more but they wont last, better to be a little conservative on the CR and not DNF with broken ring lands.

if you can find one an injection head is a good upgrade, probably not good enough to hit your target power though.

[Dyno]

Extreme difficult to get 140 Bhp out of a Pinto, still making good torque etc. A fair prepared head, Piper BP134 (better than any other cam if you want to use the DGAV on the road), small bore Ashley (not big bore), 10/1 max!! (or engine can run after and will be close to detonation because the BP134 give you a LOT more filling at low RPM, nog advance of using ore CR, only head). Modified distributor. I've seen 130 Bhp with this mods and not a single difference in torque, idle of fuel consumption compared to standard engine. It's just like a standard engine but pulling high and stronger in the higher revs (not sky high of coarse).

If you need more power and still the same torque low down, you need twin Webers.

[Dyno]

I have an injection pinto engine running a 32/36 carb, bestek electronic ignition, Ashley 2" exhaust, Piper 285 cam and valve springs. It's running 128hp with equal torque and goes well. I use the car for road/targa rallies so I'm limited by two chokes. I'm looking at the next stage in upgrading the engine and looking for advice as to what I need to do to get closer to 140/150bhp without sacrificing the torque as it needs to accelerate from.low speeds alot. I don't know whether to focus on a great head, bottom end or the induction. Appreciate any help

If this is a standard head, it will NOT give you 128 Bhp. A lot more torque and slightly more power can be found with the BP134 but without modded head it still wound give 128 Bhp.

[tom_escort_mk2]

I'm well aware that rolling road numbers may not.be completely accurate,just wanted some advice on what o needed to do to get to my target

[Dyno]

Will be more round 120 Bhp at this time but with the mods I've given you will end up with a very drivable road engine (like standard but more powerful).

More can be found with a good head and custom made camshaft. None of the shelf cams will do better, maybe the late KentCam version of the original ERSON 134 advertised as Injection camshaft. But I have never tested back to back. I also feel the lift and acc. are at the limit for a long live camshaft.

Only 23/36 DGAV race engine with a very lumpy idle, fuel burning like some can drink alcohol can make 140 Bhp. But then it is only for racing, I can't select it as a road rally engine. Even with twin Webers you will not see 150 Bhp with standard head.

[Miniliteman]

Tom,
for a near std engine the 134 cam is the best bet as onyd said when you want to retain tractability (street).
The modern version of the Piper 285 cam is not far of as it has a duration of only 270 degrees (inlet) and a lot of lift.
Years ago we mounted a carburettor of a Fiat 130, believe it was a Weber DFC 45, to a Pinto engine.
Engine had a lot more power than with the 32/36 but you have to fiddle around a bit with the manifold and linkage.
Regards, Leon.