Best Mods For An Engine

[1186497]

Hi Guys

 

At the monent i am running a standard 2L Pinto lump on a type 9. As the winter is drawing in i have confined the 2B to the garage for the cold nights. If they ever arrive!!

 

I am looking to mod the engine through the winter to tune it up so it achieves a decent 0-60 time, if you have a spare minute i would appriciate your opinions on what the best mods are to do to achieve the quickest 0-60......apart from change the engine

 

Cash is as always a big factor so the cheaper the better, however i would prefer to do it once than keep changing so if its money well spent then ill get saving

 

Thanks

Simon

[Guest hypermick]

Hi Simon,. I'm sure you'll find lots of input on here with engine mods but just to start with,.. is the engine completely standard at present (including the carb & exhaust manifold set up) ? and are you using the RH 2B standard (as supplied in the kit) twin pipe exhaust system ?

 

 

Mick.

[1186497]

Hi Mick

Standard apart from a 38 DGAS with pipercross airfilter. At the moment the exhaust is as you mentioned. Although i have a new silencer so am planning to add a 4 pipe manifold to replace the standard one, and connet it to the silencer, either by two 2.5" tubes or one coming from the manifold to the silencer, depending on if that makes a difference?

[Snapperpaul]

If you don't want too much engine work then cam change it is, but you wont get the best without some head work. Bigger inlet valves are a good start with the ports blended to the now bigger size. David Vizards book and Des Hammils will make your head spin but will guide you through it. Power is mostly about how much air and fuel you can get in and once burned how easily it can get out.

If you do take the head off then have it skimmed for more compression, after this it starts to cost more and more for less and less gain.

[1186497]

Would it be about as cheap to just get a new head off ebay etc..., if so what rod, port size etc would be best. i see your using bike carbs on your pinto?? Better than 45's or the like?

[Snapperpaul]

Meant to add that the injection head has a much better flow on the inlet side with a much more rounded sharp side turn and it's unleaded this can be worth 3 to 5 bhp on its own, a good base for a DIY job.

 

I bought my engine ready built from the Locostbuilders for sale section with Megajolt and Bike carbs. Bike carbs are considerably cheaper than Webbers. Beware Davis competition engines on ebay, there are some good heads on ebay but usually bare i.e. no cam.

Get How to Power tune SOHC Pinto by Des Hammil it will tell you most of what you need to know.

[1186497]

I got a download of it from the site a bit ago so is there ready to read, but im not a big reader!! Although the bike carbs are cheaper are they better? Sorry to ask, not heard of them being used on a pintop before

[Snapperpaul]

The power figures quoted are usually generouse but 150 bhp should be resonable, I have 130 bhp and 135 Ft/Lb with my set up and hope for 150+ when i get another head, then i will consider the Zetec we will see.

 

Bike carbs work and have been used by a lot of people on a lot of cars, most are now trying bike throttle body injection but that needs an ecu.

Boggs Brothers are the bike carb men, but what ever carb you go for you will need to set it up/ rejet it for the new fuel requirement, the DGAS i think is good for 130+ when set up so may be worth doing your build up in stages. 1, exhaust manifold. 2, cam. 3, head work. 4, carbs.

[Guest elwe]

Why not go injection?

 

A carb can only give optimal performance in one part of the rev range. With injection you can map it to optimal settings right through the rev range.

 

You can use motorcycle throttle bodies rather than the standard pinto injection system. Add a megasquirt to control it and it need not cost too much.

 

If you don't want fuel injection at least take a map-able ingnition system. Ignition timing is critical to power output. Do you really think a couple of spinning weights and springs and a vacuum advance can give you optimal settings?

[1186497]

Why not go injection?

 

A carb can only give optimal performance in one part of the rev range. With injection you can map it to optimal settings right through the rev range.

 

You can use motorcycle throttle bodies rather than the standard pinto injection system. Add a megasquirt to control it and it need not cost too much.

 

If you don't want fuel injection at least take a map-able ingnition system. Ignition timing is critical to power output. Do you really think a couple of spinning weights and springs and a vacuum advance can give you optimal settings?

 

 

So the ideal set up for a pinto would be an injection head rather than carbs?

So ideally on a £500 tune of the head what would you want......

You talk about megasquirt at not much cost..how much?

[Snapperpaul]

Injection head is unleaded, most others are not therefore you have to have hardened exhaust valve seats put in at extra cost. If you are modifying your own head then you would round of the sharpside turn anyway so the advantage of the injection head is only the hardened exhaust valve seats. For £500 you would want to see the flowbench results and i think 125cft/min at 10" is good but am ready to be corrected.

The big, big problem is what do you want from the engine, low down torque with good BHP at reasonable revs and topping out at 6,800 or balls out 7,500+ and nothing below 3,000rpm. Unless you go the whole hog with the bottom end you should be carefull at sustained high revs above 6,500 even with the injection rods.

So don't build a head that the bottom end can't take, big exhaust valves only really help at the higher end of the rev range and tend to move the peak torque higher up.

I would have bigger inlet valves, standard exhaust with 3 angle valve seats and blended in ports flowed but not enlarged, combustion chamber relieved to unshroud the valves and skimmed to restore the compression ratio, probably around 10.5 to 1.

The cam needs to match the rev limit of the bottom end, no good your peak power reached way past your rev limit.

Cosworth rods, 9,000 rpm and V6 pistons, 8,000 rpm or Fiesta diesel con rods 8,000 cheap but need a lot of work, a mod i have the bits for. Crank is good for 8,000+ but the flywheel and its 6 bolts are not, double dowl and steel flywheel will save your legs

My engine has 130 bhp @ 5,850, 2.1 on standard injection head and 285 cam, i am looking for more as we all do, so 150 ish at 6,200 or at least under 6,500 is my next target. Then i would need to buld the bottom end again.

Sorry this is a bit of long winded post but it is what i have gleened from all the publications i have read over decades about the Pinto. The bottom end is weak at revs over 6,200 and the top end cam geometry is difficult or at least must be built with great care above 6,800.

Keep it simple and do it bit by bit, or throw money at someone to build a complete engine.

[Guest alan rowe]

What about just simply a Turbo or Supercharger

 

A

[Knock-on]

My question would be whether it's simpler to just get a better engine off eBay or to tune the existing one?

[Snapperpaul]

What about just simply a Turbo or Supercharger

there have been turbo charger kits on ebay for the Pinto but you have to have the lower compression engine and that wont make much over 130bhp without lowering it again to about 8 to 1 and then you need to flow the head and sort the cam.

There are bargins around but you would still be lucky to get a turn key 150 bhp for 1000 quid with cam carbs and ignition, keep your eye on the other kit car sites Locostbuilders have some pintos in the for sale now and again as they upgrade to bike or Zetec.

Have a look at Vulcan engineering for what you can get built and guaranteed. 2.1 bottom end for 400 quid

 

Knock on it depends on what you can do yourself, i have costed my engine out at 1800 quid with ARP bolts, steel flywheel, new high flow high preasure oil pump etc. but the guy that built it had the block bored out to take the V6 pistons for 80 quid, built his own Megajolt, built the inlet manifold for the bike carbs etc.

I suppose the answer is in what i did, kept my eyes open and when the link was posted on this site i leaped at it, 800 quid for a turn key 2.1, might seem a lot for 130 bhp but it has a lot of the hard work done and will be a hell of a start for my next stage.

[Guest hypermick]

Its always difficult to know where to spend good money doing engine modifications and, the rule is to spend the least to gain the most . Below is a basic guide to tuning without specialist modifications to the engine.

 

Starting with the head first clean and smooth out the inlet ports taking away the ridge step where the valve seats meets the casting. The inlet port is about 35mm as standard, take it to about 36mm but don’t over polish the surfaces since any unburnt fuel will stick to the walls. A slightly rough surface will help break up the fuel droplets. Replace any worn valve guides and seals, valve springs, and cam bearings too. You can also re-profile the ridge (inside the port where the valve comes through) making sure that the edges are well rounded if any are left.

Personally a fast road cam would be my choice and add to that an adjustable cam vernier wheel which can normally be found on Ebay for about £50. The above is assuming your not going for larger modified (re-profiled) valves and new seats. Finally have about 25 thou skimmed off the face of the head. The correct port to inlet valve diameter ratio is about 0.86 – 0.88 of the valve diameter for most road applications. Inlet valves are normally about 41mm standard size. For exhaust valves it is fine to work on the same basis but don’t re-profile the lower half of the exhaust port since this causes the gasses to backflow into the head, instead concentrate on the upper half and radius it into a slightly wider curved shape. Don’t forget, new followers always with a new camshaft and,………..always replace the spray bar which sits above the camshaft. For the sake of about £7 ditch the old one,. Always !!!

 

Moving on, check the piston rings, replace if necessary and glaze bust the bores. Make sure the oil pump is up to scratch too since extra exertion in tuning will be relying on the oil being pushed around as efficiently as possible. Make sure also the main bearings are still good,. The pinto is very reliable on the bottom end but if you inherited it with rattly bearings now is the time to sort them out.

 

Exhaust systems. Here there is plenty of choice. Stainless steel 4 into 1 manifold lots of suppliers about who will make them up for you if not already off the shelf. The head ports should always be slightly smaller than the openings on the manifold, This will insure that the gas bursts are sent pea-shooter fashion straight into the system rather than fighting at the same diameter, where they tend to bounce across instead of making a sharp exit. Silencer and pipe can be made up to suit but dimensions are important. The standard for 2.0 ltr Pinto is 2.25” and for 1.6 ltr 2.00” o/d. Also to reduce popping on the over run the fitting of an intermediate box will reduce this considerably !

 

Carburettors. Looks like lots of interest currently in Mikuni’s and Keihins but manifolds are still the problem, costing about £180 + for one off fabrications. The carbs though are now fairly plentiful and contrary to popular belief it isn’t necessary to go to 38 and 40 mm. Ask Takumi on here he uses 34mm Mikunis with very good results. 36mm are also extremely useable remembering that your inlet ports are going to be about this size anyway. There is no mileage in shoving 40mm choke size carbs on a head which has narrower ports !! The idea is to match the inlets, chokes, manifold and ports so the flow is smooth and continuous. Also remember that Weber 40’s and 45’s normally have chokes respectively at 34/36mm and 36/38mm for most applications. An alternative method is to use throttle bodies from a bike, but the pump is also needed and mapping via a Megasquirt or similar needs to be in place. If you do want to go for twin Webers, manifolds s/hand are found for about £40, carbs anything up to £200 a set,. 45’s attract a premium !

 

 

 

Ignition, somewhere on here and also on the NW RHOC & Locost website theres mention of distributor modifications. Also places like Aldon Automotive do a hall effect trigger for Bosch distributors (very quick and easy to fit) if youre getting rid of old type points. They will also do you a custom made distributor (which concentrates on dealing with the correct advance curve) for your given engine spec. I used to buy distributors in quantity from them many years ago (in the late 70’s & 80’s) and theyre still one of the leading specialists in this field. Megajolt is the alternative solution to ignition mods plus other systems from Omex and Emerald are now available but quite expensive.

 

That’s about it in basic terms. Anything more, you need to do a bit of reading & research. Main thing is, don’t just bolt things on hoping for big improvements, each improvement needs to compliment the others so they all work together, and hopefully when it goes off to the rolling road you’ll have performance for the money spent that youre pleased with.

 

Mick