Callahan

Dear everybody,

I'm completely new here, in fact I'm from Hungary. I got a '92 Sierra Sapphire with a 2.0 Pinto EFI, and because I was never really satisfied with its power, I decided to slightly improve it. (only "low-cost")

The main thing is I'd like to raise the compression, because it's the 101HP version, and I want it to be as powerful as the iS version which had 115HP if I'm right. I got plenty of tips on the hungarian Sierra forum about renewing the head, but I'm still confused about the compression ratios.

So mine is the N4B, the iS version was the N4A, am I right? And what are the precise compression ratios?

The reason why I'm asking this, because I'd like to get 1-1.5mm off from the head (sorry for the bad english), but I don't know how much is appropriate.

If my thread is in the wrong place, please moderators put it where it should be. I don't know my way around the website yet.

Thank you very much in advance! I'll post a photo about the machine as soon as I know how to.

Best regards!

Callahan

Anybody?

Callahan

Can someone help?

robrs2

Your engine will have the short low comp pistons. They are about 1mm lower down the bore than the standard piston.
you can machine the head or block or just fit the standard high comp piston. Compression ratio is about 9.5:1

Callahan

Thanks for your answer. If I choose to machine the head, how much should I? 1.5mm? I don't want to mess it up, or to make the car lose it's reliability, that's why I want to know precisely.

Callahan

Anybody?

costina

iTrader: (1)

id change pistons. or if you really want you can skim the head and use a felpro head gasket as there compressed thickness is smaller than a std head gasket.

for pinto related issues you need this site as there more old school

www.turbosport.co.uk

robrs2

1.5 mm should be ok, it is possible to go to 2.5 mm but it depends on the spark plug hole threads. It will depend on how thick the head is you start with.

Callahan

Thank you! The engine is bone stock, the cylinder head and the pistons aswell.

Callahan

We raised the compression of the engine (we machined the head by 1.3 mm), but I still got a question. Does it worth changing the ECU? The car has it standard N4B ECU, but I'm told the N4A (the high comp. Pinto EFI) has a different one. I have got that ECU aswell, but I'm not sure whether it's worth changing the wires, etc...

What do you think? Would it make any difference at all?

Callahan

Can someone help?

matthewpickup

i would not change the pistons as it will be a shorter stroke with the shorter pistons(so will be faster revving) just skim the head and block , lighten flywheel , uprated camshaft , group a coil , magnacore leads , veriner pully and a 4/2/1 exhaust manifold

Callahan

Thank you, but what about the computer?

matthewpickup

tbh i am not sure maybe one of the msd guys could give you an idea , i run a 2ltr pinto but its the carb model so its diffrent

robrs2

The ecu will have a different fuel map for the higher CR and the ignition map will also be different. So yes fit it.

Callahan

Thank you, we've tried it today, but the idle was horrible, so we put back the original one. It goes very well with the improved and skimmed head, so I'm satisfied with the results. Do you think that computer would make it even better?

robrs2

You will need to fit the air meter that was with the ecu. They are set different for high and low compression. also you need to know if its is ment to run with an O2 sensor in the exhaust.

Callahan

Thank you, we've put that air meter in my mates car before, so I can try mine with that one.

Callahan

Hello everyone,

more than a year went past since we improved the cylinder head, and I decided I'd like to change the camshaft, because I read a lot of times that it's worth it. It's an injection version of the Pinto, and there are two Kent cams, which I'm interested in. The FR30 and the FR34. I've consulted with my car mechanic, who did the job last year, and after seeing the specs, he said the FR34 would be a great choice.

But I read somewhere, that the Kent cams are prone to wear - I beleive it was an Escort turbo CVH engine in question - and that sometimes they aren't up to the specs as they intended to be. Is this true, if we're talking about a Pinto cam? Or what else would you buy instead? I've got a slightly modified cylinder head - skimmed by 1.3 mm - with improved flow, but no porting and standard valves. I want mid-range torque instead of high revving power.

I've read that the Burton BF134 is also a superb cam for what I need. What's your opinion? Kent or Burton, or something else?

Thank you in advance,

costina

iTrader: (1)

I used to run a efi pinto back in 96 and with a really crap bottom end ie one piston was a low comp job with a FR34 cam and a 4 branch manifold and K&N filter made 128bho on the dyno. with a decent bottom it might have done more.

And yes I did have a problem with my cam which Kent replaced. it knocked out 2nd from last lobe all the rest was ok.

Callahan

It sounds great, but as you mentioned you had problem with the Kent cam, I don't know if I should buy one.

Any other suggestions with the same specs? Are other camshaft from other manufacturers more reliable?

costina

iTrader: (1)

I would buy Kent again as with all manufactures they have there failures FR 34 would be best. or you could try newman cams or cat cams. or even piper.

There was a max power mk2 escort with a injected lump claiming and 150bhp.

BigPeBe

From my understanding the FR34, BF134 or Piper Cam's 134 are very similar or maybe even the same cam. About the manufacturing quality I don't know, I have used Burton and Piper Cams products myself without problems.

And yes, when comparing FR30 and FR34 the 34 is better. TBH I would never choose a milder cam than the FR34, putting even a milder cam than that to a "tuned" engine seems pointless to me. I myself use an aggressive BP300 cam on my daily and have no problem with it (this won't work good with the stock injection tho).

When you fit a new cam also fit new followers, otherwise you might run in to problems with wear.

These cams are high lift / low duration, so tighter valve springs are advisable. You might get away with the stock springs tho if they are in good nick and not planning on revving loads above 6000.

Check follower geometry before installing. Wrong geometry will wear your cam/followers quickly. Good advice would be to check how big of a base circle your current cam has and then try to choose a cam that has the closest to this one. Different cam manufacturers and different cams often have smaller base circle and this will ruin the geometry if not using longer valves. IIRC Burton BF134 and Piper Cams 134 both have good big base circle.

I would also advice on porting the head, good porting job will make a big difference even with the stock sized valves.

I know this is an old post but no, this is very wrong. Piston height wont affect stroke, crankshaft is the one that "controls" stroke.

costina

iTrader: (1)

Great advice. I too used a full cam kit inc springs

Callahan

Thank you very much for the answer and advices!

I'm not planning to rev the engine hard, i like mid range grunt, that's what I'm looking for. So i think the springs will be okay, but we will have a look on them aswell as the geometry. I use a new stock cam right now, it's only done 5000 kms or so.

I think it will be the Kent FR34 or the Burton BF134, I will read into them, and find out which one is actually more reliable.

Callahan

Dear everybody,

I have a strange vibration issue from underneath the car, I beleive is must be the propshaft. It "begins" at 55km/h and becomes quiet at around 80 km/h. It's really annoying. In a few days we will replace the whole propshaft support, the rest of the shaft seems OK. I hope that this will solve the problem.

My question is, is there a spacer, washer (sorry I don't know how it's called) between the propshaft support and the chassis? I've found topics which say so, but I found 12-13mm quite radical. Or is just for the 2wd Cosworth?

My car is a 2.0 Pinto, so the gearbox is a T9.

Thank you in advance!

R4N SS

iTrader: (6)

check the propshaft donut

costina

iTrader: (1)

Spacer is for the cosworth never remember them on a normal sierra.

Check centre prop bearing. also wheel balance.

Callahan

OK, then I stop worrying about the spacer.

The vibration is the same with different set of wheels, so I very much hope replacing the centre bearing and support will solve the problem.

So thank you guys, we'll see.

Randombastard

Have you choosen a cam yet Callahan?

i was also thinking about the FR34 on and off if its worth paying 400euros for the "kit"

Callahan

Yes I have, it's the FR34. I bought the whole kit, but it's not "in" yet, so I cannot tell you any experience. It's only gonna happen in spring.

But I'm very impatient, can't wait to see, or I should say, feel the difference.