1500cc hot street motor build

Jepp78bertone

True Classic
hey everybody, I'm here to share my engine build progress with the hope that I can get some insight from you wise folks who have been there and done it before.

Here's a look into my project from a couple of years ago when I originally built the motor.
https://xwebforums.com/forum/index.php?threads/first-start-up.28658/

I've clocked over 100,000k of amazing adventures on it since then with relatively zero motor issues. I've made the 2,300km trek back and forth from Winnipeg, Manitoba (burrrr) to my current residence in Abbotsford, British Columbia 4 times now in the car. One of those trips was a bit more than 2,300km when I made my way down the Columbia River Gorge, across the plains of Idaho, into the desert land of Utah, and finally over the rockies were I eventually ended up in Colorado Springs to surprise my friend at her wedding. I cannot tell you enough how much I have enjoyed owning this car. Regular maintenance checks, a few sets of tires, and a new timing belt somewhere in there have been painless. Bernie at Bent wrenches auto in Mission, BC has been a huge help over the years tweaking things here and there to get the car running the best it could. Robert Maynard at RWM. & co restorations has also been an incredible source of wisdom and friendship.

Over time the car did develop an oil leak and slowly covered and caked the front of the motor and oil pan. I thought it was for sure the front main, so I decided it would be best if at some point I pulled the motor and did a good clean up. It deserved it after all, plus I wanted to put in new motor mounts as mine were gettin reallll saggy.

I finally own another vehicle to use as a daily driver so Ive actually been able to put the x in the garage and work on it without having to ensure that it was back together in time to get to work the next day. A couple of weeks ago I pulled the motor and commenced "project clean up." It really didn't take long before I convinced myself (I also blame all of you that have made your performance builds information so accessible on here) that maybe it was time to do a few things to spark things up a bit. So here we are, I've got the motor half apart, and most of the pieces cleaned up and sorted, and now its time to really begin thinking of what the heck I am doing.

Spec lowdown

1500cc motor
OEM FIAT 1300cc 86.6mm small fly cut pistons
1500 10bolt us spec cylinder head mildly ported and polished according to SteveC's recommendation
stock valve sizes (EX-33mm/IN-36mm) professional 3 angle cut done and seated
stock valve springs
camshaft - unknown (likely stock)
carbs - twin DCNF40's
exhaust - ansa 4-2-1 header to custom 2.25" to supertrapp exhaust
12.4lb lightened flywheel

My goal is to build a hot street motor. I'd love to get into the occasional autocross, and maybe eventually some track days at Mission raceway here in BC. BUT, (i know this might seem like a lot to hope for) I'd love to keep it possible to enjoy some longer distance twisty mountain road trips! I'm not afraid of the inconvenience of maintenance required in tuning the dual carbs and fiddling with all the other stuff that comes along with owning a 40 year old car put together by by a 17 year old kid (that would be me - what an amateur). I just want to gain a little bit more power, and honestly I simply want to understand my motor better, so what better way than to tear it apart and put it back together again.

TO DO LIST

-Mill head to remove circular recess
-measure compression ratio
-decide on a performance Camshaft ????
-clean up engine and repair oil leak
-replace engine mounts
-have fun learning along the way

QUESTIONS

-I know there is tons of information on the subject, but I am still undecided on what camshaft to choose. I have a few options available locally. Vics 42-82/82-42 or taking a cam blank and getting it ground to whatever spec desired. Im open to opinions and ideas, what say you?

I'm going to be making segment posts on each section of the build - cylinder head, cam shaft choice, engine mounts, etc. But here are a few progress pics so far.

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HinJepp,
Sounds good!
Regarding cams, 42/82 is was too hot for your use.
What you want is a euro 1500 cam or a 35/75.

The stock US cam is an emissions item that you don‘t want for a sporty motor.
 
There's alot to read there, so please excuse my jumping strait to the specs of the build plan. The following is just my opinion.

Save the money on milling the circular recessions and trying to convert your US head into something it's not. Start with a 1500 Euro head. They don't have the decompression rings and there's enough meat there that the head can be planned several times, and extend the life of the build. Same goes with the cam. Its turd. WhyWgo through the trouble of installing something that won't benefit the purposed other mods? Other then those your basically having a light port n polish and the 3 angle is barely more then a head refresher. Another downside to US head are the smaller valves when compared to the late Euro heads. Why go through all the effort of modifying a US head, to effectively create a Euro head or a lightly ported Euro head, but now with drawbacks like reduced head surface material, changing in timing bearings, having to used an adjustable cam gear (and the pain of dialing it in)? To me it just doesn't make sense. I also at one point wanted to attempt a very similar build. That was until speaking with Matt B, Steve C and Guy C several times each. None of them said that this is the "best" way. It can be done, no question; but it's not going to give you the results that your going to expect for the amount of money you'll spend... ?? It wasn't for my wallet. This is why I've waited and slowly aquired the correct parts, over time, and as my very limited budget would allow. Best of luck. Let me know if I can help. And if you do decide to go another route, I have on commission and in stock several of the correct parts.
 
yep, don't waste your time with the US spec head... just find a chunk of euro alloy and begin from there.

I would be fitting 37.5 intakes and going for a 37.5/33.4 valve combination and a 34/28.5 seat throat combination and then top it off with a euro cam... I do this all the time and it is simply the best bang for buck...you already have the small flycut pistons so keep the bottom end together and just fix the leak, change just the head and cam over and feel the difference that this single (sort of) change makes.

SteveC
 
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Listen to Ulix, Eastep, and SteveC above. All 3 greatly helped me in my build that just "finished" up before winter set in. If you find a head you are uncertain about please check in here. Many sources, unless they specialize in Fiat SOHC parts, don't know what they are looking at. Plus there are a bunch of variations available across the ~30 years of this motor.
 
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While I agree finding that euro spec stuff is easiest, I got pleasant results from my US version, but it was more work, which was ok for me, because I had more time than money, and an awesome machinist, that was not only knowledgeable, but super affordable. I had to do some homework tho, like where to find bigger valves for cheap (rock auto has them if you look into European Fiats built in the 90's) I also got lucky and found an unmolested 1500 carbed head, and a real eurospec cam. The only real issue I had was porting, I did that myself, and is probably not all that great, because I was too afraid to really hog it out, so I just smoothed out the rough areas. I imagine an is where an imported head would really be better
As for the bigger 1300 timing bearing, I was rebuilding anyways, and it did need to be changed. And Yes I had to use an adjustable timing gear, but I plan on getting a hotter cam later and most are regrinds, which is going to need that adjustable timing gear + I can alter, fine tune my timing to give me better low end/high end torque. I guess the thing to think of there is- are you the kinda guy that will later want more? I didn't think I was, but now I want to get a hotter cam, lol

I'm not disagreeing with the above mentioned advice- I just couldn't find a euro version of the head, nor did I know how much better they were at the time. Just saying it is possible to get performance out of that emission version head. Yeah I had to put in a little more work, but that was cheaper for me at the time... A really good relationship with a great machinist was the key for me. It was also a good learning experiance

And oh might get rid of that Fram oil filter...all kinds of info on how poorly they are made. that being said, I've used them before, never had a problem, but after I watched some vids, I quit using them. Good luck on your build
 
an awesome machinist, that was not only knowledgeable, but super affordable
Sure wish those were everywhere. I can no longer find either; not knowledgeable (with Fiats), nor affordable. :mad:

I'm assuming part of your machine work was taking quite a bit off the head, to get the compression ratio up like the Euro head? I believe that is where the Euro head differs the most, not the ports (but I could be wrong).

Unrelated to your example, but I've wondered about the US spec heads with pollution equipment. Not sure which years it includes, however I know my carb '79 Calif smog spec has this. There are internal passages connecting the exhaust ports for the EGR system. It is the head with the 'tunnel' you can see behind the T-stat housing (requiring the 'special' gasket to keep coolant from entering the ports). And it also has passages for the AIR system somewhere in there; this one has only one external connection to the single AIR tube, not the four individual tubes, so there are internal passages to all four cylinders. My thoughts are how much all those extra passages effect gas flow, even if the EGR and AIR systems are removed/plugged. It isn't possible (as far as I know) to block off all these internal connections to the exhaust. Seems they would have some adverse effect by disturbing the flow of gasses as it passes the openings, and maybe add further unwanted 'pulses' to that flow. o_O
 
yeah, the dude I know usually does big v8 stuff for all the rich rednecks that do dirt track cars and dragsters down here- he finds my endeavors- amusing (trying to make a lil 4 banger go faster)...But he was very helpful in helping me extract the most for my money
 
Matt @ MWB did my 1500 US head. Outstanding. Very close to stock valves, a mid-level, warm street cam (I can give specs if you need them). The cam was slotted to run a tower mounted dizzy (very convenient to work on). A good machine shop is worth gold. I had the block tanked, prepped, honed, then beautiful 87mm slugs put on the stock rods and crank. I was going to do the remove and replace of all the hard parts myself, but the shop did this for an extra $200. No brainer at under $900. Running dual 40's with yugo electronic ignition and lightened flywheel from MWB. Have some old PBS knock-off header and a locally made Magnaflo set up that works fine for me. The combo is excellent, accelerates hard, and doesn't poop out till way into the scary rpm's. Matt races a similar combo (although i'm sure with a lot more knowlege of specific prep and parts) with huge success. He builds for endurance, and that's what was important in my build. The only snafu for me, so far, was fuel delivery. I have since swapped out the electronic fuel pump and added a monster fuel reservoir. Until it grenades, I will call this my best build for the money. Lastly, the sound from those webers and that little 1500...glorious.
 
I really appreciate everybody's input, and I admit I really do wish I had the funds to just drop the $ on a ready to go euro cylinder head & camshaft combo, but I just simply cannot afford that option. So I've gone with a similar approach to what Kevin Cozzo has described. I also was fortunate to find a machine shop with an excellent reputation, at a very reasonable cost. It only cost me $120 to have my head milled down to remove the circular recess.

Here it is.
IMG_5129.JPG


I've ordered a burette from amazon to measure the combustion chamber volume so I can determine the CR.

For my headgasket I'll be using a heavy duty one from MWB. This one is .080 (2.0mm) thick, and has between .70-.75 crush thickness.

On my list of things now is to plug the front oil gallery hole beneath the aux shaft plate. I can simply use the 16mm dish type plug that MWB sells, or i've read that people have tapped and plugged them with a pipe plug. The pipe plug I've sourced which has a 16mm O.D. at the face of it, and a 14mm OD at the back should fit, BUT it will go in TO deep blocking off the oil passage. I'll either try and source a shallower pipe plug, or simply order the 16mm dish plugs.
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Another task I started looking at today was my adjustable cam gear. I bought it off a fellow xweber a couple years ago and it has been fitted on my 128 wagon with a stock 1300 in it. I traded it today for a stock 1300 cam pulley because it was no use on that motor other than looking cool.
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However, I noticed when I lined up the adjustable pulley with the stock 1500 pulley that the guide pin hole was slightly bigger on the adjustable cam than on the stock 1500. It was also slightly off from the exact position on the 1500.
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Am I safe to simply rotate the aluminum insert on the adjustable gear 180 degrees and drill a new hole - assuring that it is precisely in the same location as the stock guide pin hole?
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Going for the thick head gasket kind of negates a lot of the gains from the head skim, as well as introduces another (unwanted) variable.

Your Squish / Quench number is the measured distance between the piston crown and the flat area of the combustion chamber opposite the spark plug. You want this tight, at about 1mm for a street engine. By skimming the head you've improved the SQ figure by loads... stock it's the decompression recess depth plus the head gasket compressed thickness plus however far down the bore the piston crown sits (about 1.5 + 1.4 + 0.4mm so approx 3.3mm) and it's pretty woeful from a performance perspective.

By getting rid of the recess, using the euro 1300 pistons with a slight block skim and now if you use a 1.75mm thick head gasket when compressed... your S/Q is still going to be wide, at over 2mm.

You really need to aim for a head gasket in the 1.0 to 1.2 mm range when crushed... SQ is important for HP and torque... getting it down as close as you can to that 1.0mm figure will pay dividends.

SteveC
 
View attachment 20210
However, I noticed when I lined up the adjustable pulley with the stock 1500 pulley that the guide pin hole was slightly bigger on the adjustable cam than on the stock 1500. It was also slightly off from the exact position on the 1500.
View attachment 20211
Am I safe to simply rotate the aluminum insert on the adjustable gear 180 degrees and drill a new hole - assuring that it is precisely in the same location as the stock guide pin hole?
View attachment 20213

Why not simply unbolt the center & reinstall it in the correct orientation? I'd have to assume the PO took it apart & incorrectly asembled it, it cettainly looks like it was tortured :D Looks like my Miller's Mule item. The notch simply indicates the tooth alignment, it makes no difference if its in the center of the tooth valley or offset in the valley.

X19-0409.jpg
 
If I understand this right, the two pulleys have completely different orientations of the dowel hole and the timing mark? If so, that's because one is a 100 pulley which uses the timing mark on the engine mount and the other is a 1500 pulley which uses the timing mark on the cam cover mounting plate. I ran into this on the 1500 installed on my 77X which worked fine as the engine mount had the timing mark. I swapped it for a proper 1500 pulley and used the cover timing mark. Works fine either way, you just have the match the pulley to the correct timing mark.

I also bought an aftermarket cam timing sprocket and the guide pin hole was larger than stock and allowed about 1/2 tooth variance....I decided not to use it as this was a non-adjustable pulley and it was just going to mess with stock cam timing.
 
I really appreciate everybody's input, and I admit I really do wish I had the funds to just drop the $ on a ready to go euro cylinder head & camshaft combo, but I just simply cannot afford that option. So I've gone with a similar approach to what Kevin Cozzo has described. I also was fortunate to find a machine shop with an excellent reputation, at a very reasonable cost. It only cost me $120 to have my head milled down to remove the circular recess.

Here it is.
View attachment 20207

I've ordered a burette from amazon to measure the combustion chamber volume so I can determine the CR.

For my headgasket I'll be using a heavy duty one from MWB. This one is .080 (2.0mm) thick, and has between .70-.75 crush thickness.

On my list of things now is to plug the front oil gallery hole beneath the aux shaft plate. I can simply use the 16mm dish type plug that MWB sells, or i've read that people have tapped and plugged them with a pipe plug. The pipe plug I've sourced which has a 16mm O.D. at the face of it, and a 14mm OD at the back should fit, BUT it will go in TO deep blocking off the oil passage. I'll either try and source a shallower pipe plug, or simply order the 16mm dish plugs.
View attachment 20208 View attachment 20209

Another task I started looking at today was my adjustable cam gear. I bought it off a fellow xweber a couple years ago and it has been fitted on my 128 wagon with a stock 1300 in it. I traded it today for a stock 1300 cam pulley because it was no use on that motor other than looking cool.
View attachment 20210
However, I noticed when I lined up the adjustable pulley with the stock 1500 pulley that the guide pin hole was slightly bigger on the adjustable cam than on the stock 1500. It was also slightly off from the exact position on the 1500.
View attachment 20211
Am I safe to simply rotate the aluminum insert on the adjustable gear 180 degrees and drill a new hole - assuring that it is precisely in the same location as the stock guide pin hole?
View attachment 20213
Please don't forget that when you mill the head, block deck, or cam carrier, down the stock cam timing mark is no longer accurate.
 
Another thing - with maching the head, make sure the head bolts (which ones are you using?) don't bottom out in the block with the reduced height. Check the seated length of the bolts in the block, and the protrusion through the head to confirm. Make sure your two HG / head guide sleeves are present and accounted for, and that the HG is properly centered over the bore when placed over the guide sleeves.
 
Going for the thick head gasket kind of negates a lot of the gains from the head skim
Hey Steve, Matt has a thinner Racing head Gasket, but says it's for an 88mm bore...could he use this? Or perhaps you know another source?

Your went all out on that skimming man, I wasn't that brave, but I have bigger intake valves, and was worried about piston to valve clearances as I also used 1300 pistons with small valve pockets, and I used the HD thick gasket...but since your not using larger valves, well then, might as well get as much squish as you can like Steve C was saying. The thing I always worried about was blowing head gaskets, it's the no 1 problem people have on these cars (usually from overheating, from not maintaining cooling system) But one of the other reasons I didn't shave so much. You could go copper head gasket, but I've heard of problems with those...maybe others will chime in...I think that's more of a full blown racing thing..

You could probably re-orientate that cam gear as you are mentioning and just mill new timing marks with a dremel cutting wheel...just be careful and keep distractions at a minimum...It's easy to get lost, and you don't want a disaster, even a couple of degrees could mean conflict. Mine has screwy marks, I think for motor mount lining up, and I simply used the old one to "center the cam", then removed it, and put the adjustable one on the cam box, and made my own mark...Just make sure your new pin hole allows equal adjustment movement between the inner and outer pieces...and you are going to need an adjustable one after you shaved that head...will also come in handy if you get a aftermarket cam,(most are regrinds, and have a smaller base circle) and then you can use a shaved down cam box, which will eliminate having to use extra thick valve shims, or lash caps on your valve stems...
 
I'll throw out a thought from my experiences and opinions.
High compression on a street engine isn't always fun. Requires high octane fuel, and/or programmable fuel injection, and/or other precautions to prevent detonation. Also cooling system upgrades will be necessary to combat the increased running temps. As well as potential head gasket issues, which might best be dealt with by using ARP head studs and a MLS gasket. In other words it opens a whole new set of related side effects you will need to address with a full package of related mods to keep it together and drivable. No shortcuts or cost savings allowed.
 
Make sure the head guide sleeves are milled as much as the head is milled. They can hold the head up off of the deck if they are too thick/tall.
Mine measured like they would be OK, they were not- initial startup OK until I saw the 'chocolate milkshake' on the dipstick... took a week to clean up, grind down and redo. Very messy, after just cleaning up the motor and engine bay.
 
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Change of Plans and Finally executing some progress.

It has been 2 years since I've made any progress on the x19 engine build and its about TIME to get it back on the road.
However I've made some changes to the engine build plan and I'd like to share this process as I put it all together.

The old plan was to use the original US spec 1500cc cylinder head milled down to remove the circular recess to bump up compression. The machine shop ended up removing 0.085" stating that they needed too to ensure the head surface was perfectly flat, even though I had requested they only milled enough off to remove the circular recess. I measured the combustion chambers with my burette and they only measured between 25.2-26cc resulting in my CR being far higher than I had anticipated and it was simply a poor choice on my end to have the head milled without specifically clarifying that the max amount removed should be no more than 0.065"-0.070".

So I've abandoned that head and am starting fresh with a brand new NOS Yugo 1100cc head that I will modify in similar fashion to the way Rob Plenter did his on his 1603cc engine build. See his thread for his awesome build including what he sourced for a lightweight valvetrain. Which I wish I could afford doing myself. https://xwebforums.com/forum/index.php?threads/1603cc-engine-build.25589/

CYLINDER HEAD build plans are as follows
- starting with a NOS yugo 1100 10 bolt head w/ 36/31mm IN/EX valves
- M10 stud holes will be drilled out to M12 to fit ARP head studs
- Combustion chambers opened up from 80mm to 86mm to suit 1500cc bore size. Initially just copying the stock 1500 combustion chamber shape until later to fine tune the cc and maximize swirl into the cylinder - Essentially trying to replicate a 1500 EURO head
- All seats are being replaced to suit 39.5mm Intake and 33.4mm exhaust valves
- Ports are being opened up to 28.5/29mm and Bowl work blended into larger seats as per stevec's ultimate SOHC guide
- Bronze valve guides to be installed and trimmed back to be flush with port roof
- 3 angle valve job and 30degree back cut on all valves
- sinking the exhaust valves slightly lower than the intake valves as per stevec's recommendation (plus i'll be using my old 33.4mm exhaust valves from my old head and they have been ground a touch before so this will move them up a tad to match the brand new AE Intake valve length )
- cam housing surface of head shaved 1mm (0.040") to accommodate reground cam's smaller base circle

CAMSHAFT
- PIPER cams FIAX19BP300 regrind camshaft
- advertised 290 degree duration BUT I emailed Piper cams and they stated duration @ .050" = 258 degrees
- advertised Valve lift = 11.18mm BUT measured Cam lobe lift (32.9mm overall lobe height - 22.8mm base circle) = 10.1mm lift (I've emailed Piper cams to ask why this would be and if it seems right)
- Valve timing - 39-71/71-39
- Stock cam tappet buckets with 3.5mm shims (+/- 0.05mm)
- Using Alfa 8mm Lash caps to achieve Valve clearances of Intake .010" and exhaust .012"
- Still deciding on what valve springs to use - either ISKY race springs or a set of new Alquati springs. Depending what I end up confirming about the cams max lift will determine the route I take for springs.
- Adjustable Cam pulley - what I believe is a Millers Mule brand

BOTTOM END
- Stock 1500cc block bored out to fit 86.8mm pistons
- Stock 63.9mm crank and con rods / new bearings installed throughout bottom end when built in 2015
- FIAT OEM 1300 Small flycut pistons (only markings on the crown are a small stamp that says "fiat113" and the marking 6/10) CH unknown. 0.6mm pop-up "pimple"
-piston is currently sitting 0.5mm below deck at TDC, I am considering disassembling the bottom end and having the block decked to have pistons at zero deck , but still need to finalize head gasket choice/and crunch the numbers to achieve Squish/Quench of 1mm.
- Will also need to determine how to go about enlarging INTAKE fly cuts on pistons to accommodate new 39.5mm intake valves (ive heard this can be done with the pistons remaining the block, but I have yet to find any information on it, can anybody walk me through this?)

CARBURATION
-2x weber DCNF40's
-Port matched intake manifold
-32mm chokes
-ITG duel DCNF foam air filter

IGNITION
- YUGO Bosch Electronic Ignition
- Bosch Distributor
- Doug's (rx1900) premium ignition wire set

I will attach photos of progress as I go
 
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