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Discussion Starter · #1 ·
I am in the process of building a turbocharged 1.9 HO for an escort project. The pre 1988 large journal crankshaft will be used along with a roller cam head. The cylinder head along with the intake manifold will be developed and flow tested using a Superflow 600 flow bench. I have read many UK cvh builds where porting was done on the head, but no actual flow bench testing was done. I am attempting to develop the head and the intake manifold (usually the intake manifold is left alone - why spend $$ on head porting and flow testing without the intake maifold? Makes no sense to me).

I will be using Cosworth connecting rods:


The intake manifold with BBK throttle body:


The turbocharger Garrett T3 .48 turbine - 55 trim compressor:


I will be using the UK Escort RS exhaust manifold.

The fuel management and spark management will be done by Haltech E6X with 550cc RC injectors:


Cylinder head work:
Initial flow testing with minor removal of material shows 165 cfm @ 28", not bad but room for improvement.



 

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Well you should have no problem making enough power to break a stock piston. :p


It's weird seeing a 1.9 build where the owner is willing to spend some money on good parts. Normally what we get around here is some one wanting to turbo there Escort but only have paper clips and popsicle sticks to work with.
 

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I hope to build something better as soon as i start working :) i finish my first year in college as an automotive service tech. Since i havent had the money i never looked into what rods and pistons will work. nor had time to find out the bearing size of the stock 1.9 crank to know if undersized or oversized bearings would be needed and all that fun stuff. I did buy a ms, planning on getting a relay box and some wires for it soon and try to do some diy tuning :) At least im making an attempt and not quitting on the escort :)
 

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How much did those Cossie rods cost? If you're able, try to snag a 1.6 head, it can be broken. It'll show how much porting can be done to the HO head, as the 1.6 has much larger ports. The intake ports can be opened up on the HO a bit as well from what I've heard, but pictures are scarce. Sounds like it'll be a fun build. That HO head, is it roller cam based? If you don't plan on modifying it to fit a 1.6 cam, then I'd go with roller lifters personally.
 

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Discussion Starter · #8 ·
The Cosworth rods cost ~$600.00 for the set. They are for a Zetec engine, but non standard length, and use a 22mm pin. These require custom pistons and the large journal crankshaft resized to Zetec rod journal ~ 0.039" under required.
The rods were used for the Ford Zetec turbo rallycar effort in Europe
when the Zetec was used.

I will be using the 36-1 Ford trigger wheel with the Haltech management.
There are several sample fuel and ignition maps out on the web for 2 liter turbo Mazdas. I will use one of these as a base map, and tune from there.
I will certainly reduce compression ratio to the 8:1 to 8.3:1 range. The hemi chamber does not like high compression - as there is no quench to aid combustion.
 

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Discussion Starter · #11 ·
I had pondered a zetec build as well, I just like the simplicity of the cvh engine. Half the valves, half the cams. An unported zetec head flows 185 cfm @28" - and that is without the restrictive intake manifold. I suspect 165 cfm with the entire intake manifold.
With the 1.9 HO 175 cfm with the intake manifold on should be possible.
For a 6000 rpm limit (The HO roller cam does not have enough duration
or lift to be effective over 6000 rpm), one does not require any more than 170 cfm. More becomes pointless unless turning much higher rpm.
A 300 cfm 4 valve head is quite useless under 6000 rpm. Drive a Honda RSX and you will know what I mean. These cars are actually quite slow unless you are above 6000 rpm.

The second limiting factor is traction. And we don't have a Quaiffe option for doubling our traction either.
 

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You could import a BC gearbox, but then it might have trouble holding up to the power. Agreed about the roller cam, or any of the other HO cams that were available back then. Technically the hemi does have a quench area by the way. The piston dome comes very close to the chamber walls, pushing gases into the valve reliefs of the piston on top. It may not be as much as the lean burn engine, but it's better than early 1.6 models with flat top pistons (and lower compression). Also, to aid in the build, use a 1.6L head gasket, as the 1.9 gasket has way too big of a bore diameter (it's meant for the 2.0).
 

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Discussion Starter · #13 ·
The UK BC gearboxes are very weak, they also would require different axles. A giant step backwards - and very, very expensive.
The mtx75 would be a better option - although still quite an undertaking, and expensive.

You are correct that the 1.9HO with the factory domed pistons does technically have some quench - but the distance between the dome and the combustion chamber is far greater than 0.060" making it a very ineffective quech zone - actually leads to more preignition trouble.

A turbo 1.9 would have flat top pistons with 2 valve reliefs - one could design a piston with a dome area on one side following the chamber closely (0.060" or closer) and then a dished portion to get the compression ratio back into the 8:1 range. I don't think it is worth the trouble.

I will be using the 1.6 UK turbo head gasket, or possibly the Cometic 83mm bore gasket. You are correct about the Felpro gasket with the large bore fire ring.
 

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Ford actually specifies using Plastigage to check the "squish" area between piston dome and combustion chamber. If you like I can scan the shop manual and show you this...it's definitely no farther than the aforementioned .060" on both sides. If you're wanting that much quench, though, why not just go with a 2.0 SPI head? It can fit the same roller cam as the HO, has a larger intake valve, and the intake side should flow plenty more. Only the exhaust side would need to be opened up, and a little shrouding removed from around the valves. That way you can use SPI shaped pistons which are half-domed. It's starting to sound like the 1.9 is not quite what you're wanting.
 

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Discussion Starter · #15 ·
I am not here to argue with the Ford manual about the squish area on the 1.9 HO head/piston. Who would use the factory cast pistons in a turbo application. You must have seen several turbo builds resulting with broken cast pistons. I choose not to go this route. I wouldnt use cast pistons in any preformance engine build - NA or forced induction.
The factory cvh pistons are not overbuilt - thin skirts, tiny piston pins, etc... far from over engineered like a Porsche 911 Mahle piston.
The spi pistons are not any stronger than a 1.9 sefi piston - neither any good except for standard use.

The stainless valves I am using are larger than the SPI anyhow. I have avouded an SPI for many reasons - one must replace the powdered metal valve seats, and the intake manifolds are incredibly restrictive.
The hemi chamber is not the best, but I like the light weight 1.9 crank.
 

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Replacement cast pistons are much, much heavier duty than the stock TRW ones. That's why I went that route in doing my build. The pistons are holding up just fine, too. They're Silvolites..nothing special, but the skirts are about 1.5 times as thick, and the actual tops are much thicker, with better machined valve reliefs, overall better casting.

If you're going with a custom piston setup, you could use the SPI shape. I've seen a fair share of messed up pistons, mostly from detonation and broken ring lands. I've also seen cracked tops from the squish area not being measured correctly or even checked, due to the head being milled. The piston kept coming into contact with the combustion chamber wall, and over time it caused a lot of damage.

Larger than the SPI valves? I can see the exhaust size being that large, but the SPI intake valve is already larger than the aftermarket large valves that can be had for the 1.6 head. I'm guessing custom valves as well, along with larger seats.

Do you have any flow bench data regarding the SPI and HO intakes? I'd love to see that.
 

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canada1 said:
I had pondered a zetec build as well, I just like the simplicity of the cvh engine. Half the valves, half the cams. An unported zetec head flows 185 cfm @28" - and that is without the restrictive intake manifold. I suspect 165 cfm with the entire intake manifold.
With the 1.9 HO 175 cfm with the intake manifold on should be possible.
For a 6000 rpm limit (The HO roller cam does not have enough duration
or lift to be effective over 6000 rpm), one does not require any more than 170 cfm. More becomes pointless unless turning much higher rpm.
A 300 cfm 4 valve head is quite useless under 6000 rpm. Drive a Honda RSX and you will know what I mean. These cars are actually quite slow unless you are above 6000 rpm.

The second limiting factor is traction. And we don't have a Quaiffe option for doubling our traction either.
Your head flow numbers do not make sense and are meaningless. Head flow is based on the valve lift and standardized at 28".

A stock SPI head at max valve lift of 0.405" flows 133.9 CFM on the Intake and 108.55 on the exhaust.

Those are real numbers ... I have a bench.
 

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Oooh, good stuff, Rex. Might you be able to flow bench the SPI intake and see what it's capable of flowing vs. a 1st gen HO intake (if you have or can borrow one of those for testing)? I'm still wanting to see numbers proving the SPI intake is more restrictive.
 

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Discussion Starter · #19 ·
Hi Rex,

My 1.9 HO head is being tested using a Superflow600. What bench are you using? My flow numbers arent fiction.
In fact your "flow" numbers are very low. Are you sure you arent flowing an SEFI head?

I am not some backwoods idiot posting useless information.
I have an engineering degree, and certainly know what head flow testing involves.
The 1.9HO head intake port was reworked, and oversize valves installed.
The flow I have quoted so far was at 0.450" valve lift 165 [email protected]".
A stock untouched 1.9 HO is ~ 150 [email protected]" and 0.450" valve lift.

I have seen published SPI head flow numbers that are well above what you measure.
 

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hey canada. im still have more need for an explanation of the haltech. there web site seems to not have posted directions. but will you make a 100% new harness or splice a haltech harness into the stock one and replace the oem computer all together? or goes it just wire into the cam,crank sensors, coil pack and maf? as well as add on a map sensor?
 
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