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lockyer89

Fuel Pump, Fuel Reg And Different Camshaft

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All of the above i have been recommended by the rolling road company. I'm running a KCFR33, which is a 300 deg camshaft. The guy's at CFM Engineering say i'd get more power from a lesser cam, perhaps a 280 degree as compression is low... Also running a facet solid state fuel pump and filter king regulator... There are a couple of different options:

 

Two different options for the Facet Fuel Pump;

 

Fast Road - Up to 150 bhp, 18 Gallons p/hour and 4 - 5.5 psi

Competition - Up to 180 bhp, 25 Gallons p/hour and 6 - 7 psi

 

 

And finally the Fuel Reg - Filter King

 

67mm bowl - suitable for up to 150bhp

85mm bowl - suitable for over 150bhp

 

The Rolling Road came out at 140bhp, the guy recons he could get 160bhp with those mods, which would mean i'd have to go with the second choice of each...

 

Anyone have any thoughts?

 

The bottom end is standard, Pinto btw!

 

Cheers

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I'm a bit mystified by the suggestions for change. I doubt the changes suggested by your rolling road will increase your power but may give a nicer engine to drive. Firstly 140 flywheel is not at all bad for a pinto. You don't say what mods have been done to the head, what carbs you are running, what exhaust, what ignition. The essence of old fashioned tuning is balanced mods. ie. the sameish level of changes applied to all the above systems. You don't fit a race cam to a standard head with pierburg carb and O.E. log manifold. However you may have to modify in stages and put up with an unbalanced set of mods as you develop the engine.

I had a piper 285 cam in my pinto with twin 40's, 60 thou skim and a bit of home porting on the head and a four branch exhaust. It drove almost like a standard engine, apart from the extra power. A nice fairly conservative fairly conventional balanced set of mods. The one thing I regretted was not going for a 300 cam. Due to the light weight of a seven you can fit a stage wilder cam without the bogging down at low revs that you would get with the identical engine if it was still in its heavy sierra home.

Rather than downgrade your cam I would suggest you upgrade the cylinder head. Easy to do with an electric drill and some burs to clean up the ports. Take it in to an engineering shop to have a skim and three angle valve seats cut. If you have a half decent carb (webber 32/36 or better) and a four branch exhaust you will have a fairly balanced set of mods for less than the price of a new 280 cam. (and more power)

The standard sierra mechanical pump or basic facet will cope with these mods OK.

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The set up I've got is as follows; stage 4 head, 44.5mm inlet and 38.1mm exhaust with valve seats. 4 branch exhaust manifold, twin 45 webers and lightened flywheel. Standard 205 bottom end, fitted some arp conrod bolts to make sure. Standard Sierra ignition. It's running the mechanical fuel pump. I think that's where i'll go next, upgrade the ignition. Would you recommend a facet with filter king reg? Cheers

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I can't imagine changing your fuel pump will make any difference whatsoever. I ran twin 48 webers on a 2.1 pinto from a standard mech fuel pump and never once had any problems.

 

From what I've seen on this forum, on average, most people get up to about 160ish bhp from pintos.....and all the power from come's from the head. By the sounds of your head, the only real improvements you could make to increase bhp would be to have it skimmed to raise the compression ratio.

 

Also Megajolt 3D iginition would give you 1 or 2 bhp more but set-up properly gives you a really smooth drivable engine.

Edited by steamer
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Hi,

you have mentioned low compression several times.

How do you know its low?

If its caused by bore or ring wear, get that sorted first.

Having had all that work done to the head I would expect it to be skimmed as part of the upgrade.

The manual pump is fine, especially as it pumps more fuel as the revs increase.

An electric pump needs to be held back at low (engine) revs by the regulator.

I agree with Nigel...I had an FR32 cam (285) & wish I had fitted the FR33..

The pinto has plenty of grunt & the light car can easily tolerate less torque.

I'm puzzled by the RR suggestions.....a higher capacity pump & a regulator will make b$$$er all difference to

the engines power, and a lower spec cam will actually drop power.

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Twin 45's, big valves stage 4 head, four branch, ARP con rod bolts and a 300 cam. You are just about there with only fettling to do. That 140bhp is probably at the wheels (or should be!). ARP flywheel bolts would be a good move next time the engine is out. Port matching the manifolds would also be a good move, especially if it's a robinhood exhaust. If it is a RH exhaust manifold it might be a good move to get something better. I agree with steamer that mapped ignition is next.

I wonder what was done to the head? With big valves I too would expect a good gas flowing job and raised compression. Any idea of combustion chamber volumes? Is it a healthy engine? A compression test would be the test of choice to determine that. If low or uneven or improved by 5ml of oil down the bores, then a rebore out to 2.1 would be next.

I wonder what evidence the RR found to suggest fuel starvation?

I wonder what snapper will say? :)

 

Nigel

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Bob I only say low compression as that's what I was told, thinking about it though, having a cam that kicks in at 3000rpm, compression won't rise until I'm within the cam duration...I bought the engine fully rebuilt and refurbished. I've had it apart to inspect so I know it's good. I will get myself a compression tester and let you know what it reads.

 

They also advised not to run a return from the webers...but I'm guessing that's if I go with the pump and reg...

 

Any who, I think I'm going to stick with what I've got for the mean time, I've spent the past 10 months rebuilding this, I need to get out and enjoy it!! MOT booked for Saturday morning!!

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Nigel, it's a Westfield exhaust manifold, actually fit much nicer than the standard rh one! I will contact the guys I got the head off to see exactly what was done, I got that a little while back. This is the first engine I've actually built up myself so it's been a learning curve!! Just getting my head around compression ratios etc..

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That spec is about as far as you want to go with a Pinto, an extra few BHP will cost loads.

Mapped ignition will provide better response at lower revs to match the cam,

but as Steamer says, it wont boost max BHP by much. Above about 3.5k rpm the ignition point wont change.

Any system that gives a big spark at the exact right time will be as good as any other.

 

Just enjoy!!!

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Overlap duration reduces static compression however dynamic compression is a calculation the Americans use to work out the required fuel RON/MON that the engine needs

I noticed that Burtons had marked an engine (Pinto) ready for collection as 190psi so I sumise that this is a static compression test bench mark that you could compare your engine to in the first instance

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I wouldn't run a return from the webbers with the mechanical pump or electric. As long as the floats are set right on the webbers and the needle valves are in good condition they should be happy and as long as the fuel pump is in good condition you should be OK. Would be good if the head supplier can fill you in on the specs of the head. Expected CR with what head gasket and it would be nice if he had balanced the combustion chambers too.

 

Nigel

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Like Nigel says, no need for a return with webers, run my twin 40's now for 8 / 9 years with electric pump and a regulator set at 3.5 PSI without issue.

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Perhaps the RR operator meant you had too low a compression ratio for the cam duration. Therby fitting a 285 degree would be more suitable for what you have. This will give more power because its a better match, or balanced engine to your compression. Also if a tuner is worth his or her salt they can measure the length of primaries and secondaries on exhaust manifold and add that into the equation. If I remember correctly a standard pinto is worth 115bhp on a good day in standard trim.so 140bhp flywheel is still good. As for further development I would consider a good ignition system any day. In your case I think 40dcoe/dhla carbs would be ideal but you wont notice any flat spots in such a light car by keeping 45's. As for raising compression, it would be easy to suggest thiner gaskets with a head skim, but clearances need to be checked first.As for the fuel issue. Well I agree with the above in as much as it shouldnt be an issue. But are you getting fuel starvation at the moment.  

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