STROKER MOPAR DYNO CATASTROPHE! THE UGLY TRUTH! Bigger isn’t always better!

[@mrho4speed]

Thanks for another great video!!! Proof that anything at any time can go wrong = you never know when something bad may happen. All the more reason why details and proper preparation are crucial to good engine building. Always good to see and learn from your channel. Keep up the good work!!!

[@goldsgarage8236]

I'm glad you enjoyed the video, thanks for watching! AG

[@Sir.Veza_]

Excellent video but more importantly very informative. Wish there were more honest engine guys around like yourself. - I've heard it said; "There's a sucker born every minute"! My Sucker Minute came last year when I paid BIG BUCKS and got scammed by having a self proclaimed "Die Hard Mopar Nut" build me a 408 Stroker. In reality he only ASSEMBLED me a motor, NO bench run NO dyno. Several Issues I have to deal with - (if I even want to continue with it) and no help from the "BS builder". The car is away for the winter but it left me with a very bad feeling for the upcoming spring.

[@goldsgarage8236]

Sorry to hear Stephen. I hope you can get it all sored out.AG

[@Sir.Veza_]

@@goldsgarage8236 Thanks

[@DarrylDutton-y3b]

Hi, great video, love 440's. I'm a retired firefighter. My EMT number was 666. It went on every ems report. Lasted quite a while, I was surprised!

[@goldsgarage8236]

Thanks for the comment and story, I've always admired our first responders.AG

[@pockets5628]

The 1.75” throttle bore/1.375” venturi is the original 950HP. I believe nascar carb. They flow an actual 820-830 cfm, but because of the strong booster signal, often make more power than a larger venturi carb. One thing to check, and especially with all newer holley/quick fuel/brawler carbs is if the throttle blades actually open 90 degrees to the bore. I have had close to 20 new ones in my hands the last 5 years. Not one was set properly from the factory. Primary over center, or under. Then the same for the secondaries. Most with billet throttle plate have a throttle stop screw. Set that for proper primary opening, then the link rod from primary to secondary needs to be bent to allow the secondaries to open fully. I use a metal ruler to check if the blades are 90 degrees to the throttle bore.

[@goldsgarage8236]

That’s really good information, thanks for sharing! AG

[@stevenbelue5496]

Good comment about the butterflies, so true

[@BrandonLeeBrown]

We always get more power with the "old" 850 than the newer 950 Holley. Holley did have a newer 1000 cfm model which was the 850 model updated, but I don't find it listed anymore. The 950 has a smaller body or a smaller throttle plate, I forget which. Years ago, people used to put an 750 or 800 body on an 850 throttle plate, but I think the 950 is the reverse of that. It is different from old 830 NASCAR Holleys.

[@StuartBlake-iz6rf]

Alan, great video. You really proved your case and point about dynoing your engine after rebuilding it. It is definitely a necessary step for a complete upgrade with the maximum result and time-effective practice. the vocal feedback of each step made perfect sense to me and I enjoyed the troubleshooting shakedown of each issue. This conclusive analysis is definitely the way to go and can only grow your viewership. Congratulations

[@goldsgarage8236]

Very nice comments, thanks Stuart. AG

[@billfioretti3013]

Alan, Thank you for the insight into the Mopar engine. Rear main seals can be problematic. Many of these "Classic" engines leak oil and if they do hopefully minor and easily rectified. If they continue to leak, just chalk them up to "Marking their territory." Also, very lucky that the valve seat issue did not occur at speed. Could have been catastrophic. Congratulations on the 22K Subscribers, Alan. Your hard and diligent work is paying off!

[@goldsgarage8236]

Awesome comments, thanks so much Bill. AG

[@4speed3pedals]

Smokey Yunick suggested that when you get an engine buttoned up to fill the crankcase with the proper amount of oil and turn it on end to check the seals stating that if the seal is going to leak when running, it will leak just sitting in place. It has to stay in that position for a while. This is something an engine stand will not help with. This test will work for both the timing cover and the rear main seal. Nick Garage had a big Mopar leak oil and it was the grooves in the crank journal. He had 2 cranks and the one without the grooves leaked. Glad I am a Chevy guy.

[@goldsgarage8236]

That is a really good tip. Thanks for sharing! AG

[@DarrellWatters]

Bill actually mentioned that off camera, he was gonna do that, 👍🏻

[@karlsracing8422]

Chevys leak too.

[@karlsracing8422]

Use the billet retainer and top fuel seal.

[@davidleary823]

Chevy has nothing to do with it

[@yarrdayarrdayarrda]

Our dyno has a temperature probe that clamps to the oil filter to allow monitoring without pulling drain plugs/etc. On the critical stuff I'll get the oil and water temps to the same level every pull to avoid unintended variables.

[@goldsgarage8236]

Thanks for sharing that tip. That's really helpful information! AG

[@chuckschillingvideos]

That would be easy enough to rig up with a multimeter and cheap thermocouple. Oh, and a piece of tape.

[@kloeppky6613]

Great video again! What is the cause of the dropped seat and what will need to be done to fix it? Look forward to hearing more. Thanks

[@goldsgarage8236]

Thanks Kloeppky, We will have some pictures and a follow up when Bill gets it disassembled.AG

[@alvarsdzenis4739]

The booster venturi's on the 950 have larger holes. The 1st couple runs show a lean condition, around 10.0 to 12.1 or so for the A/F ratio. Mopars tend to like 13 to 14. The last pull with the other carb richened the the A/F. Great content Mr G. Might I suggest for further dyno room vids, concentrate on the dyno screen and less of the back of the dude's head.

[@goldsgarage8236]

Thanks for the tip, I will try to show the dyno screen more in the future. AG

[@TimothyArnott-m7z]

Hey AG, Tim here, Fast Fish makes the BEST BB MOPAR rear main seal fix......i went thru hell on a REAL Hemi Road Runner ('69 auto, very rare) we didnt build the motor, but was trtin to help the guy out.......3 tries (motor still in car) bought the Fast Fish rear main kit, with retainer.......DONE!!.....MOPAR Joe had a similar issue.......i suggested the fast fish, he got one, its DONE!!.....FAST FISH makes the proper fix for BB MOPAR rear main!!

[@goldsgarage8236]

Thanks Tim, appreciate the input.AG

[@johnsartelle8320]

It's on the exhaust, isn't it ? Stuck the valve. So it was either too tight or too lean, or both.

[@goldsgarage8236]

Thanks John, actually it was caused from a valve seat falling out. AG

[@johnsartelle8320]

@goldsgarage8236 Oh,that's crazy. I haven't seen that in quite some time. BTW previously, I was Comet. New device 🤦‍♂️

[@VInceAcosta-g4e]

other than a stroker mopar descriotion can we get a cubic inch size and compression ratio determines whether those values are reputable

[@goldsgarage8236]

Thanks Vince, it is 500 cu. in and 12.2 CR. AG

[@christopherdwayne1110]

Ok I have worked on cabs all my life , why does lowering the float level make it leaner? It will change tip in , but I can’t see it changing the afr very much. Any body want to explain this thanks Dwayne NZ.

[@goldsgarage8236]

Thanks Christopher. I think the theory is that hydrostatic pressure (pushing the fuel into the jets) is proportional to the depth of fuel in the bowl. Actually i never thought of this before and haven't researched or tried to calculate the numbers, but it worked. Lowering the level worked and when they installed smaller jets, power increased. i will experiment on this myself in future dyno tests. AG

[@dondotterer24]

That's awesome torque!

[@goldsgarage8236]

699.3, It was pretty impressive, right? AG

[@dondotterer24]

@goldsgarage8236 yes. I will have to tell my friend that is an engine builder and has a Dyno

[@Sunspot-19]

My favorite quote from a Yew Tewb presenter, "Of course we had to machine everything, it's a Chrysler" -Jim's Automotive Machine Shop, Inc. A wee bit of humor for ya Allan!! Gitter sorted and it;ll haul ass!!

[@goldsgarage8236]

That is funny! It's definitely a Chrysler engine. AG

[@Sunspot-19]

@@goldsgarage8236 Laughter is one med that has the fewest side affects!

[@goldsgarage8236]

perfect, thanks AG

[@markmcmullen1371]

Ouch, sorry to see that happen, I've been there done that myself, good show, 👍👍👍

[@goldsgarage8236]

Thanks Mark, engine building is not for the faint of heart.AG

[@magnusdanielsson2749]

Was there not enough press fit? Brisn Salter mentioned in his video that he always use 7 thousands press fit for his valve seats in alu heads. Claims hes never had one fall out even on very high perf engines.

[@goldsgarage8236]

See RAMBRUTTE's comments above.AG

[@dennisford2000]

Rather than being concerned with the cfm difference in 850/950 , I would look at cleaning up the shafts to make it tear drop shape, removing half the shaft to start, making the shaft from brass to allow soldering a wedge after the shaft to the blade, radiusing all the upside on the airhorn. Easy to find a lot of stuff to work on to allow airflow…

[@goldsgarage8236]

Thanks fro watching and commenting Dennis.AG

[@GrandPitoVic]

Congrats on the subscribers brother!!!

[@goldsgarage8236]

Thanks, appreciate it! AG

[@patrickterry779]

That’s what she told me too! 😆 Thanks for the video!

[@goldsgarage8236]

Haha, I'm glad you enjoyed the video! AG

[@stevenbelue5496]

Why are y'all not discussing the choke horn changing flow characteristics and being a restriction as Ive always thought that was the main cfm difference vs an HP or chokeless. Milling the choke horn off and radius, smooth the inlet sorta using the mindset of a valve job so much above and so much below the venturi's or is that the wrong way of thinking and doesn't help?

[@goldsgarage8236]

Thanks Steve, I will have to discuss this with Bill.AG

[@JayGuitars1]

A 950 is basically a 750 with a 850 baseplate. I remember when they came out in the late 90’s. I think they flow round 930cfm.

[@pockets5628]

830 is actual cfm of the original 950HP. 1.75” throttle bore and 1.375” venturi.

[@JayGuitars1]

@@pockets5628hey I knew it had a 30 in it 😂

[@roberthollinshead2325]

Good stuff but sorry to see that seat failure. What brand heads? It will be interesting to see what the cause was.

[@DarrellWatters]

Edelbrock Victor heads

[@trentdawg2832]

Even american edelbrock pieces arent safe in 2025!!!!!

[@scottcummings18]

I had a ford m400, rebuilt the short block and bought aftermarket heads. After 800 miles it started missing. When i got home 3 dead cylinders. Pulled the heads. The seats were sucked up in the head, with the valves just hanging. Lucky i didnt drop a valve. Put new heads on it and still driving it today. That happened 17 years ago.

[@patrickterry779]

Damn! That was some good luck! I still run the cast closed chamber 4v with port fillers and larger 2.25 valves with orig cast in valve seats except 2 which I had to put in and for some reason I worry about those 2 😂

[@goldsgarage8236]

Thanks for sharing your experience guys.AG

[@petercunningham3469]

Hopefully there will be something left to measure when you tear it down sucks tearing a new engine down for an obscure failure but.

[@goldsgarage8236]

Thanks Peter, we will follow up on this project.AG

[@ericuncapher9922]

Yikes. Great video Mr.Gold

[@goldsgarage8236]

Thanks Eric.AG

[@jimmungai1938]

Back in the 90s, a friend of mine bought a set of elder Brock heads for his 302 Ford and I ran real nice and stuff like that but it dropped the seat also

[@goldsgarage8236]

I think that happens to more people than you think. Thanks for watching. AG

[@trevorfraser6235]

I would like to get in touch with you I have a 355 sbc needs refresh it run ok still but valve train needs attention floats valves

[@goldsgarage8236]

Thanks Trevor, you can text me at 226-980-7499. AG

[@RAMMBRUTE]

That's very disappointing and surprising it dropped a seat. Those seats are from Durabond's "Killer Bee" series which were developed for the LS3's. They were installed with .006"-.007" interference with warmed up head castings and cold seat inserts. There were probably 45-50 . 3500 rpm-6500rpm dyno pulls on them and while I had valvetrain instability problems the seats were not one of them. Hopefully you can either select a slightly larger seat or there is some welding needed. Either way not fun. Oh and I've also had my share of rear main leak headaches with the Big Mopar platform. Google "440 rear main leak-almost suicidal" on Moparts you can read about my 7 attempts to stop a rear main leak. The solution was surprising and I use this process every time and have not had a leak since.

[@goldsgarage8236]

That’s great information, thanks for sharing!AG

[@alleyoop1234]

I haven't heard of a dropped valve seat since I had a Corvair!

[@goldsgarage8236]

Actually the valve seat fell out, We will have some pictures in a future video. AG

[@alleyoop1234]

@@goldsgarage8236 Yes, that is what happens to Corvair heads too.

[@stevenbean9706]

its got different internals want to see something crazy swap baseplates

[@goldsgarage8236]

Thanks for the advice Steve. AG

[@rogerstill719]

I think that carburetor is 824 cfm . I think it has a 750 main body with an 850 base plate

[@goldsgarage8236]

Thanks for the info Roger.AG

[@anthonygatt-c7p]

Because the 950? Flowed at a higher vacuum

[@DarrellWatters]

The 950 had 2” of vacuum at wide open, the 850 had 2.6” at wide open, which dictates the 850 was more restrictive and flowed less air.

[@goldsgarage8236]

Thanks Darrell.AG

[@bobgrim9605]

Maybe that valve seat wasn’t installed properly

[@goldsgarage8236]

Check out the following comment from the original builder. AG

[@jtrill2]

Audio is super low. Has been in the past. Want to watch but hard to.

[@goldsgarage8236]

Thanks for the comment. I didn't realize that. i will have to watch it myself. We just bought new microphones and i thought they were working pretty well. AG

[@robertheymann5906]

Thx for the video. Audio is low

[@goldsgarage8236]

thanks Robert, a few viewers have made that comment. We just bought better sound equipment, so i don't think it is that. I guess we just have to speak louder in the future. AG

[@mikeg4163]

Holley 950hp is not the cfm rating, it’s just the name of the carb. Yes it’s a bit of trickery by Holley.

[@goldsgarage8236]

Good info, thanks Mike. AG

[@dennisford2000]

1:55am or pm

[@goldsgarage8236]

pretty sure PM Dennis. I don't work nights anymore.AG

[@timosracecars]

850 holleys flow 850 wet. 1030 dry. 950s flow 930ish dry.

[@goldsgarage8236]

Thanks for the info Timo. AG

[@philthelawnman]

I can tell by the oil stains in a drive what make car they own.

[@goldsgarage8236]

that's a good one, thanks. i think many of the vintage cars were prone to leaks. AG

[@karlsracing8422]

Frankenstein engine, i would had him build a more common stroker engine with reliable parts.

[@goldsgarage8236]

Thanks for commenting Karl.AG

[@jtrill2]

I dont like how this guy dynos. The engine is heavily loaded up at lower rpm then hes slow to get to revving it. The dyno should be calibrated to that engine to apply load more gradually and fully when the engine is revving. You can tell by how it sounds ultimately. Would never go to this guy. They even talk about it here in the video bc it caught there attention. Normally this dyno loading conversation doesnt come up bc dyno is done right.

[@TomSmith-cv8hk]

Say what now, the heads will make more power on a smaller motor, that'd be a first.

[@chuckschillingvideos]

There are *many* other variables and considerations than that.

[@barrybaker9677]

ATM CARBURETORS ARE WHAT THEY SAY THEY ARE ❤. GOD BLESS EVERYONE AND TRUST IN OUR LORD AND SAVIOR CHRIST JESUS 🙏.

[@goldsgarage8236]

Thanks for watching and commenting Barry. AG

[@anthonygatt-c7p]

Sorry I was sure that they said the 950 had 2.6

[@goldsgarage8236]

No problem anthony.AG

[@markstopkey4085]

Can't hear you.

[@goldsgarage8236]

Sorry about that Mark. We will work on improving. AG

[@passinggear]

Just use a rope seal.

[@goldsgarage8236]

Thanks, a few other commenters agree with you. AG

[@bigal878]

Unless you can get an old school asbestos rope seal, forget it. New rope seals are rubbish. Neo seals are generally leak free if correctly installed (I’m going from my experience in SBC and Holden V8). Unfortunately Hemis have a crap real seal design.

[@passinggear]

I have had great success with rope seal 440 source sells. Just saying. m.kzbin.info/www/bejne/Y6PYcndoqb-YfNk&pp=gAQBiAQB

[@passinggear]

@@bigal878 I have had great success the rope seal 440 source sells. Mancini also has a rope seal.

[@bradblakeley3408]

The mtr would make 40 more hp with a dominator , bigger headers. Thats why its rich . Stop using wizbang carbs .

[@goldsgarage8236]

Thanks for watching and commenting Brad. AG

[@luckyyocich7371]

These guys will never work on my engine...lol...

[@hughobrien4139]

That’s unsettling.

[@goldsgarage8236]

good to hear from you Hugh.AG

[@brianholcomb6499]

Those old Chryslers are known for rear seal leaks! Whether it was the seal, or leaking around the cap 🙄🙄🙄🙄! I think we have all been through that! I’m wondering if that exhaust valve issue was going on once it got warm? Because I’ve dynoed 100s of engines, & they aren’t usually shaky like that was! Unless there is a balance issue, or a dead cylinder ect! I wouldn’t say the head guy did a great job, if your valve seats fall out! Bending a valve is not a disaster, when something comes through the block, that’s a disaster! If you put a dominator on it, it will make more power! Too small of a header really doesn’t help! I hope the builder can fix it easily! Because it’s not his fault, when a seat someone else put in, falls out! I can’t imagine the hours he has into it 😳😳😳😳!

[@goldsgarage8236]

thanks for the comment Brian, you might have something there. AG

[@82cabalero]

just like edelbrocks dominator type carb,they say made in amerka,but the parts are made in china and sent to edelbrock,then dale puts the pieces together,to me thats assembled in amerka ,to be built in amerka,the parts made in amerka and assembled in amerka is made in amerka

[@goldsgarage8236]

Thanks for commenting Allan.AG