Dual point distributors are still quite limited by the available dwell angle. If your goals aren’t much more than the original 271hp 289 K-Code engine, then I’d leave the smaller valves. If you are using real HiPo heads, consider their value before modifying them substantially. Also, re-grinding the cam is less than ideal, you haven’t got much to work with. I can highly recommend the Comp Cams N271+ grind for a 289, it makes great power for a given combination, but you have to be careful with flat tappet cams and manage your valve spring pressure carefully.

Aftermarket gauges are not compatible with stock senders and vice-versa unless it’s specifically designed for the OE sender (73-10ohm fuel level sender for example). If you’re putting the new gauges in and they duplicate the stock gauges, it’s kind of redundant. Warning lights use switches not senders, so obviously they aren’t compatible either. The new gauges should come with electrical senders, if not, you’ll need to get them from Stewart Warner. Don’t try to connect the two gauge systems together, it simply won’t work.

@@TheGT350Garage hmmm??.. thanks for responding. Just to clarify, I wasn't trying to use both systems together, Nor the idiot lights. Also the 68/9 Shelby mustang came with the SW blueline gauges mounted in the console behind the shifter. I thought the original Ford sending units woukd have been used in conjuction. In ex: The 90 degree oil pressure gauge is calling for a sender with R - 240 ohm.???

@SallyS-f2q understood. If they are original AO Smith spec Stewart Warner GT350/GT500 gauges, then use the 68 GT350/GT500 Wiring Diagram supplement and the appropriate jumper harnesses from Branda in conjunction with the Ford senders. If they are modern gauges, that does not apply, you will need to wire them to a key on 12v power source and treat them as aftermarket gauges using the supplied senders. Here’s a helpful link: www.thecoralsnake.com/Electrical.html

13.5:1 with a dome isn’t ideal. The dome interferes with flame travel. Shoot me an email if you’d like some guidance on how to improve the combustion event and make the chamber work better with the dome. TheGT350garage@gmail.com

Thanks. I’m working towards new content on this subject very soon.

Shoot me an email to TheGT350Garage@Gmail.com

I use the Comp Cams 26986 Beehive springs with 7° steel retainers and machined not stamped locks. The install height needs to be 1.850” which will require longer valves or cutting the spring pockets. If you want to go the valve route, just realize you’ll need to address pushrod length (longer) and possibly rocker studs. If the heads are not converted to screw in studs and guide plates, that is mandatory. Then you’ll need to check the contact pattern on the valve and be certain the rockers and pushrods are correct for the application. For valves, I recommend SI Valves Portflow valves for street drivers, or their Competition series for mostly performance used, all of which are good quality for the price point in the intended application.

No, if you use Lambda values to base the tuning on, Lambda 1.02 at idle with “1960s” 14.7:1 stoichiometric gasoline would be 15:1. With modern E10 14.2 stoichiometric gasoline, Lambda 1.02 is 14.4:1. It’s a seemingly “richer” air/fuel ratio, but only because stoichiometric ratio for the fuel is lower due to the oxygenation from the ethanol content. The combustion quality or completeness is the same, meaning, the emissions profile out the tailpipe is the same if not a little cleaner.

Aluminum transfers heat out of the combustion chamber faster and more efficiently than cast iron. In a performance application this means aluminum is a little less prone to detonation if you compare two identical casings in the different materials. I’ve done this test before with World Products/Roush heads back 25-ish years ago. Same castings, same combination, different cylinder head material, aluminum made slightly less power (down 2-3hp) at the same timing and air fuel ratio. Aluminum tolerated about 2° more total timing though and because I could run that through the entire curve, the aluminum head hedged out the iron unit. If you’re building an iron head combination, shoot me an email with your planned usage and the specs and I can offer some advice to get the most out of it.

Vacuum advance adjustment, I’m lazy, I do it on a running engine, I set the timing so the engine idles without the vacuum advance and then just apply manifold vacuum and check the timing. I’ll adjust the internal screw with an allen key, and recheck until I get what I want.

It’s easier to extract the potential from a lower octane at lighter demand. With 91 RON being the “Minimum” per the manufacturer you’re certainly safe to use it. If you were working the engine harder, you’d want to use the 95 RON. Choose a top tier fuel (a brand or brands recognized for selling a higher quality product) and perform your scheduled maintenance on time or a little early.

If the heater core is also 30+ years old, I would pull it and service both.

Thanks! I’ve been very busy this year, bought a newer home which includes a much larger GT350 Garage 2.0. Remodeled and sold my old home, and we’ve had some major family related events that demanded my full presence. The new garage is almost set up, and I’ll be back to making content in a few short weeks.

@@TheGT350Garage congrats! What state do you live in? I'd love a big enough garage one day to spread all the projects but I'm working out of a smaller 2 car garage, lucky enough to have that even here in California.

I don’t know whether to like your comment or not, lol. The gap in the advance slot I give in the video produces 20 degrees. That should be the target for most engines these days. You are correct about the limiter bushing being subtracted from the slot width to determine the gap, and you can also measure the two gaps on any given limiter plate, and the difference in gap between the two is the difference in crank degrees. So if a 10L/15L plate measured 0.625 / 0.750 (not actual measurements this is an example of how to calculate the it) the 0.125 difference is 10° at the crankshaft and each .0125” would be 1° at the crankshaft. I’m still relatively new at the RU-vid thing and I try to keep an outline for the videos and hit all the important details but clearly I make no claim of perfection.

To test the Instrument Voltage Regulator you will need to pull the instrument cluster from the dash, you should have battery voltage on one side and 5v on the other testing to the metal cluster ground point for the regulator. Where this can and often does get skewed is at three common locations; the ground connection of the IVR to the instrument cluster, the harness ground from the back of the cluster to the cowl under the dash, or the engine to firewall ground wire in the engine compartment. Each of those three locations can produce high resistance in their connection and cause gauge problems. This unwanted resistance will allow the IVR to produce more than the 5-volts and results in higher readings. You can easily verify this with the fuel gauge as well, if your fuel gauge also reads high, this is the issue. If the fuel gauge reads correctly and only the temp gauge reads high, I would suspect a faulty sender. That can be verified with an ohm meter. It’s a linear sender: 250F = 10 Ohms = Gauge Reads H 100F = 73 Ohms = Gauge Reads C Every 10°F over 100F you add 4.2 ohms, so at 180F you should read right at 39.4 ohms from the terminal post to the sender housing threaded into the intake manifold, also from the red-white wire to the back of the instrument cluster (ground) with the sender connected at the engine.

​@@TheGT350Garage super helpful, thank you! the fuel gauge does a similar thing where just 8 gallons in a brand new tank and fuel sending unit will read as "full" on the gauge. i doubt the brand new unit is faulty, so it sounds like voltage regulator issue. oil pressure gauge reads low but i checked that manually, which was at 20-25psi at idle and probably close to 50 at higher rpms.

It can be done on the car, but an on-car flaring tool will make the job much easier.

Fools and their money are easily parted. E85 is a joke, and the joke is on people like yourself who think it’s better than pump 91-93. The garbage they call E85 from the pump is wildly inconsistent and has to be tested tank load to tank load due to wild variations in ethanol content. Canned E85 is expensive enough you may as well run proper racing fuel. And if you’re only running WOT, you probably have a 12-15 second attention span so I doubt you grasped the concepts presented in this video.

So what you’re saying is you want expert level knowledge passed onto you in such concise detail that you’re fully capable of competently tuning your own engine in under 10 minutes. You’re probably the same guy who thinks professional tuners overcharge their customers for a few keystrokes and a little dyno time. This isn’t a video for people with the attention span of a toddler. You either stick with the video if you really want to learn something useful, or you go back to watching RU-vid Shorts and TikToks that better suit your learning style. And I read your first comment before you deleted it, feel free to not like or subscribe based on what you said there.

I have seen them leak slowly and only occasionally smell of coolant. It’s an easy job really to remove and rebuild the heater. If you’re concerned, you needn’t be, it’s really not that difficult, just be patient and take your time, the whole process can be done in a weekend or a series of week nights.

I’ve had quite the year and haven’t been posting new content but thats about to correct itself. Look for an update in the next few weeks and I hope you’ll get some additional value from my efforts moving forward. Thanks for watching!

In my experience, you’re either dealing with an incorrect pointer and balancer relationship, or you are using a timing light that is misinterpreting your ignition timing. A lot (most) digital timing lights can’t handle multi-spark CD ignition outputs. The multi-spark output skews the timing light signal making it seem like the engine is tolerating more timing than it is actually operating at. I’ve been using the Pertronix Digital HP ignition more the past few years and with great success, and one of the key features I use on it is the ability to disable multi-spark for timing purposes. Now, it’s also possible your engine is not actually 10.5:1 and your cam may be bleeding off so much compression that you effectively have far less cylinder pressure than you think. Running a compression test correctly will tell you the engine’s pumping performance, and identify a cylinder pressure issue. Using an analog (old school) timing light can help you identify an issue from your ignition system. And finally, putting a piston stop in the no. 1 cylinder can help you ensure the timing pointer is truly reading TDC at TDC. The final caveat is that some cylinder heads (you don’t state what you’re using) have truly terrible combustion chambers, meaning they are inefficient and cause a “slower” burn rate leading to a need for more ignition timing. This is a common problem for D shaped wedge type chambers like FE Fords, but some Windsor heads (OE and Aftermarket) are affected by this chamber shape issue.

@@TheGT350Garage The pointer was checked. Old style ported Trick Flow heads. Compression test, with a cheap tester is about 185 and even. Cam is 231/239 @.050 and 110 LSA. And I just use a basic timing light. Ignition is just a Fast brand ready to run deal. No multi spark. Thnx

Ok, if you’re using old school High Ports, especially aluminum, then yes, you’re in the ball park, at 42°. Those heads have a rather slow chamber. I would caution you to be careful with the rate of advance, meaning don’t run an overly aggressive curve, bring in total at 2800-3200rpm, and use vacuum advance to improve idle and cruise efficiency and lower operating temps. Twisted Wedge heads, be it a 15°/17° 170/185/205 head, a Twisted Wedge R, or the newer 11R series, have a much more efficient chamber and for your cylinder pressure on a 347 they would want 34-36° max, all in at 2600-3000. It would be worth a couple hours on a dyno to set up the air fuel ratio and then optimize the ignition timing on the car at several points in the rpm band to find the ideal shape for the ignition timing curve your combination truly wants or needs.

If you use the same ignition timing and air fuel ratio at 8.8 and 9.3 you’ll need about 1-2 additional octane points, or as you’ve observed an increase from 87-88 to 89-90. Your assessment that the engine requires the addition of more octane is because you have ignored both the air fuel ratio and the ignition timing in the OE fuel injection. Optimize the air fuel ratio and you’ll find the engine can return to the original octane rating by running at .84-.86 Lambda and you’ll also be within 1° of the original ignition timing. Making the same if not more power than you are on 90 octane with the lousy factory fuel and spark mapping.

@TheGT350Garage Not having access to high end tuning equipment leaves me kinda going old school. With success I'm happy to report..using live data to monitor o2 sensors and fuel trim led me to a lean condition. Plug reading confirms this..a small vacuum leak was repaired and colder 3923 plugs installed along with low ohm wires has me burning the rot gut again 😆

“High End” tuning equipment is not really necessary. You can’t rely on fuel trim data from a narrow range oxygen sensor though. They can only detect Lambda (Stoichiometry). If the sensor’s cut point for stoichiometry is .450v (450mv) any time you’re below that you’re lean and any time you’re above that you’re rich, but in either case you have absolutely no way to know how lean or how rich you actually are. If your ECM was originally built with the assumption that the stoichiometric ratio of the fuel was 14.7, the sensor will perpetually give a lean signal to the ECM because modern ethanol blended fuel hovers in the 14.1-14.2 range. So your fuel trims will always show roughly +5%, or 5% lean, and if it’s an older (pre-2005 ecm it’s a challenge to interpret this). This is where you do need a wideband oxygen sensor and with kits in the $200 range now (they were $3000+ when I started tuning) it’s no longer a high end tool. If you adjust the fuel pressure up or use a slightly larger injector (assuming it’s speed density and not mass air flow) you can get back to the correct air fuel ratio without needing to reprogram the ECM. Whatever you do, you need to stop thinking it’s a fuel quality issue and realize it’s actually a simple adjustment to a slightly different stoichiometric ratio that’s needed.

“Homie” is writing a book on this topic, teaches it professionally after doing it professionally for 35 years and has the ability to use grammar and the English language fluently in a comment. This is content from the book, not someone else’s work, if you think that, you’re welcome to get lost and follow the pundits of misinformation elsewhere on the internet.

Let’s hit this comment head on. You’re dead wrong about fuel quality, modern fuel is VERY good. Its clean in the sense that it doesn’t need nearly the level of filtration fuel did as recently as 25 years ago, but compared to the fuel used in the 1960s it’s drastically better quality is every respect. Modern fuel burns more efficiently and cleanly than the old fuel blends, it produces equal or greater power by weight as well. You simply don’t seem to understand it, and this is where you are getting in trouble. The first notable thing is watch my video on tuning for high compression using pump fuel, you’ll learn a lot if you pay attention and keep an open mind. Secondly, watch my distributor curve video and again, pay attention and you’ll learn a lot. I explain in both of those videos how to set up the ignition timing on these older engines. You’ll need the information from both videos. If you don’t have the patience to spend a couple hours learning, you can always shoot me a super thanks and an email and I’ll take my time explaining it to you in that format. Suffice to say your temperature issues are likely timing and air fuel ratio related, but since I’ve already provided the information in those videos I’m not going to keep dragging out responses.

Email: TheGT350Garage@gmail.com

If you have a 1-piece oil pan gasket and the gasket stays intact, a little 1/4” bead of ultra grey across the gasket at the block where the timing cover gasket meets the oil pan gasket and also where the oil pan gasket goes under the timing cover around the crank will do fine. If you use the cork ends that come on a timing cover gasket set, use a thin layer of ultra grey to attach them to the cover and install the end seal like you would normally. If you didn’t drop the pan, it’s a little tricky to get it all lined up but not a big deal. Just do t get carried away with the ultra grey. A smear on the timing cover gasket, and bond it to the cover first let it set up if you aren’t in a rush, then the same on the other side before installation. Don’t try to use the ultra grey as the only seal, while it would probably work, you’ll need a priest to exorcise your demons after the swearing fest you’ll have taking it apart down the road. I once had a customer buy a long 5.0L block I built and use probably 2-1/2 to 3 full tubes of black silicone trying seal it up for installation. It was fine for a couple of minutes then it lost oil pressure. He got really accusatory about my build and pulled it out, we stood behind the build and I stand behind my work to this day. There was so much silicone in the pan and lifter valley I pulled it out by the handfuls. Needless to say it wasn’t my fault and on seeing the pictures and that the oil pump bypass was stuck open after the oil filter plugged with the stuff, he apologized and paid for my time and the parts to fix it. The old saying “A little goes a long way” really applies with gasket makers and silicone sealants.

As long as your fan and radiator are in good condition,, the 192 thermostat is fine. I suspect you have tuning related issues. If the timing is not correct and the air fuel ratio is not correct, these engines will run warm. 220 at idle is hot but not overheating, it’s usually caused by timing or issues with vacuum leaks causing a lean condition.

Viscous fan clutches are fine with air conditioning, but not well suited for the high rpm of a performance engine. They are also heavier and shorten water pump life because of the loading on the pump bearings. I don’t really have any issues with them in practice but they don’t have a place in a performance application. I’ve had similar questions about electric fans (there is not adequate space in Gen 1 Mustangs from the pump to the radiator) so people want to run pusher fans. You really need the high airflow below 35-40mph, above that it’s all about getting the air through the grill into the radiator core and out.

Not sure what you’re asking. 6AL (any magnetic pickup capable ignition) you use the two wires connected to the pickup, you can remove the ground wire. No need to remove a sticker, just connect the purple and green leads from the MSD to the pickup.

Brake fluid itself is not the best choice for a lubricant.

That’s because you grandpa was smart… sure it’s not the absolute best lubricant, but it’s definitely the best for this exercise, BECAUSE you’re only flaring brake lines AND it’s not a foreign lubricant that you’ll have to make sure is cleaned off before using the parts

Absolutely, but I moved and that meant setting up an entirely new workspace.

Lambda is the best way to explain this, and metric volume and mass make it all easier to understand. 1hp requires ~0.563 grams per second of air. So if you have a 200hp engine it needs 112.6g/s of air. 400hp would need 225.2g/s, 600hp would need 337.8g/s. Lambda gives us better insight into the quality of the combustion process. Naturally aspirated engines can tolerate a leaner mixture and as a result lambda under maximum output will be .84-.88 where a turbocharged engine under a maximum of about 15psi boost will be .80-.84 Lambda. As boost pressure increases lambda changes very little, only about .02 for safety by 30psi. (Side note, you need to move more air volume at lower pressure to reduce heat and improve efficiency or you’ll need more fuel to cool the mixture down). Lambda is the air fuel ratio you need by multiplying it by the stoichiometric ratio of the fuel. So pump 91 is 14.1-14.2:1 these days, that means your target air fuel ratio is 11.3:1 on the rich end and 11.9:1 on the lean end under power. At 200hp you need 112.6g/s divided by 11.3 to arrive at 9.96g/s of fuel. The specific gravity of fuel is ~.74 so 9.96/.74 means 13.47mL/s or 808mL (0.808 Liters) of fuel per minute. Divided by the number of cylinders, and divided again by .80 you can get the injector size for 200hp. At 400hp you need 225.2g/s divided by 11.3 to arrive at 19.93g/s of fuel. The specific gravity of fuel remains ~.74 so 19.93/.74 means 26.93mL/s or 1615.9mL/m, 1.616 Liters of fuel per minute. Divided by the number of cylinders, and divided again by .80 you can get the injector size for 400hp. You’d run the same numbers for 600hp but be aware that as boot rises above 15psi so does the temperature of the air charge. Also, if you were using a centrifugal or positive displacement supercharger the numbers are different because you don’t see the parasitic losses to drive the supercharger in the flywheel horsepower. This is why Brake Specific Fuel Consumption (BSFC) on engine dyno tests is always higher on superchargers than turbocharged or naturally aspirated engines. An Eaton 2.3L TVS on a 2.0L engine would support 600hp with ease, but it will take 70-90hp through the belt drive to make the power, which means if you make 600HP with that supercharger you need enough fuel to support 670-690hp. Hope that answers your question.

@@TheGT350Garage it did more than just answer thanks. if you provide tunning lessons or whatever lessons to help increase knowledge in the auto world i would sign up

Shoot me an email to discuss consultation.

Thanks for the completely useless comment.

Based on the info in your other comment, cruise should be 13.5-ish. The open chamber heads, small cylinder pressure building cam profile and the moderate compression ratio will need to be just a hair richer than a more optimal setup.

Fuel is interesting stuff. It’s easy to think the octane rating has something to do with flame travel but it’s really just an indicator of ignitability the higher the octane the more stable it gets. Once it’s lit, 87 burns about the same speed as 91-93, 96-100, and 100+ octane fuels. Add to that the air in the cylinder is the limiting factor in the combustion process and the oxidizer that helps that fuel burn. The fuel was adjusted to the air the engine consumed and the timing is determined by the compression ratio, piston and chamber shapes, so once the air fuel ratio is optimized timing isn’t going to be much different regardless of the octane.

@@TheGT350Garage Cool, thank you for clarifying. So for gasoline it's about the same. I should have mentioned that I was thinking about ethanol vs. gasoline, not so much about the different octane ratings. That's why I imagine that there are effects at work e.g. charge cooling vs. fuel vaporizing, that cancel each other out to make a net 0 difference in this case. Like, if we look inside the chamber it might burn slower at a glance but there is less mixture in the ring land which would have taken longer to combust. So the optimum timing stays about the same.

@maikgoldmann5691 ethanol does have a cooling effect, and it carries 33% oxygen by weight, so as a fuel, it takes a lot more of it (thus the near +50% volume difference vs most gasoline blends) and even though you have more oxygen, because you have a larger total volume of fuel, the speed the fuel burns remains relatively constant to a given combustion chamber. I’m not a fan of pump E85 at all, it’s horribly inconsistent and you bad need to test every batch before using it to estimate the stoichiometric ratio and then adjust your tune accordingly. “Race E85” is at least consistent, but it’s nearly the cost of proper race gas. You actually get more benefit from installing a water/methanol injection system and running straight distilled water with pump 91-93 octane than you do from any version of E85, and if you want power gains, you can run up to 50% M-1 methanol (fuel) which will allow more timing and a slightly leaner fuel flow through the carburetor or injection system. Sadly, the perfect setup doesn’t exist in my experience, because that would mean having an ECM that monitors air/fuel ratio, EGT, Knock, and adjusts both the fuel injection and water meth injection actively and has protection against running out of water as well as the ability to progressively meter it against the tune.

Eastwood and Earl’s sell a very similar tool that works well under the car, but like anything, the preparation is key.

10:1 is absolutely fine as long as your quench clearance is .040-.060”. Any more than that and you start getting detonation in the quench area. If you’re using a dish and it doesn’t match the shape of the combustion chamber that’s also problematic. But 10:1 is a good starting point. You want to make sure your cam duration and specifically the opening and closing events produce the ICL, LSA and thus overlap you need for best results. People tend to get in trouble by using too small a cam or running a larger cam that leans towards building too much cylinder pressure in lower to mid range operation, and that too complicates the process.

@@TheGT350Garage it's actually a 1.8 ltr. mgb engine, very slight dish, 6cc, kidney shaped chamber. Presently at about 9.5:1, runs great on 93 octane but below that, I really have to back off the timing. the head is cracked across two seats, been running fine for the last 20k but feel like it's just a matter of time before it fails. I acquired another head but later found that it was skimmed .060 and think it would take me above 10:1. I have I new stock cam and runs great, smooth idle. Do you think a light porting would positively tone down posible detonation, thanks in advance.... Luc S...

@lucsavoie9501 port the skimmed head lightly to improve airflow, simply working in the bowl to contour the guide bosses and remove any casting flash or machining peculiarities in this area of the port and profiling the combustion chamber to unshroud the intake valve, and lay the deck back down to the seat with a gentle transition inside the gasket opening along with getting a slight 1/16” or so radius on the chamber anywhere it’s exposed to combustion combined with a proper valve job, and you can make big improvements in about 4 hours time plus the valve job. Then get a “Fast Road” type cam with duration in the 260-270 range to take advantage of both the compression and flow, you’ll have a very fun little combination. The one thing to consider is the piston to deck clearance, I generally build to 0.000” and set piston to head clearance with the gasket. Ideally you’ll want 0.032-0.035” clearance, if that clearance is more than that because the piston is below the deck, and you can’t get a thin enough gasket to get in that range, consider decking the block. It will further increase your compression but substantially decrease the likelihood of detonation in the quench areas.