521 Refresh questions

I'm in the process of redoing my 750Hp 521 and wanted some opinions from the forum. I currently have a Scat 9000 4.30 crank in this engine. I'm looking to boost the Hp level up to 800-825 and spin it up to 7000rpm max. I'd like to change the crank to a stronger piece but i'm not sure what I need. Would a Scat steel crank be ok at this power level or do I need something else? Second Question- Rods. I currently have Scat H-beams with ARP 2000 bolts. Adequate? Or should I step up to something like an Oliver piece? I guess I should mention that this is a Drag Race only engine, launching off a transbrake (4000rpm). Thanks for any input.

650jetmech wrote:I'm in the process of redoing my 750Hp 521 and wanted some opinions from the forum. I currently have a Scat 9000 4.30 crank in this engine. I'm looking to boost the Hp level up to 800-825 and spin it up to 7000rpm max. I'd like to change the crank to a stronger piece but i'm not sure what I need. Would a Scat steel crank be ok at this power level or do I need something else? Second Question- Rods. I currently have Scat H-beams with ARP 2000 bolts. Adequate? Or should I step up to something like an Oliver piece? I guess I should mention that this is a Drag Race only engine, launching off a transbrake (4000rpm). Thanks for any input.

A steel crank is probably all which is needed in the short block; maybe a higher compression ratio.
The top end would probably need some work for that extended RPM level.

Thanks for the input. Valvetrain upgrades are also part of the plan. The new cam is a Kaase part. 272/280 @.050 .774/.770 with my 1.8 rockers. At a minimum I want to change over from my Comp 836 lifters to a bushed lifter from BAM or equivalent. Were also talking about Ti retainers and anything else I can do to lighten the valvetrain within my not to large of a budget. I’d like to crack 800Hp on mainly pump 93oct with a little bit of race gas. So I was hoping to keep the compression ratio around 11:1 with my AFR 295 heads. Other than that we’ll be adding a windage tray and maybe modifying the front sump pan with a small kickout. Its topped of with an AFR intake and an 1150 dominator. So I think i’ll make my Hp goal but I also want a reliable piece that will go 300-400 passes before another refresh.

650jetmech wrote:Thanks for the input. Valvetrain upgrades are also part of the plan. The new cam is a Kaase part. 272/280 @.050 .774/.770 with my 1.8 rockers. At a minimum I want to change over from my Comp 836 lifters to a bushed lifter from BAM or equivalent. Were also talking about Ti retainers and anything else I can do to lighten the valvetrain within my not to large of a budget. I’d like to crack 800Hp on mainly pump 93oct with a little bit of race gas. So I was hoping to keep the compression ratio around 11:1 with my AFR 295 heads. Other than that we’ll be adding a windage tray and maybe modifying the front sump pan with a small kickout. Its topped of with an AFR intake and an 1150 dominator. So I think i’ll make my Hp goal but I also want a reliable piece that will go 300-400 passes before another refresh.

I Would Go to 12/1 Compression with That Cam. Mix Race Gas If/When Needed.

How Many Passes on The H-Beams???

^ If A lot I Might Replace Them With New H-Beams. Maybe Molnar's. The Oliver, or Whatever High Dollar Sounds a Little Overkill to me Though.

If You can Score Some BAM DLC Coated Lifters, That Would Be Sweet.

Also .904's, or The Next Size, If It was Me With Funds.

^ The Above (Lifters) is A "Big Bill" Though on The Lifters, BIG!

Plus+1 On Lightning The Valvetrain. Every Little Bit Helps, Even at Low RPM Like 7K.

650jetmech wrote:I'm in the process of redoing my 750Hp 521 and wanted some opinions from the forum. I currently have a Scat 9000 4.30 crank in this engine. I'm looking to boost the Hp level up to 800-825 and spin it up to 7000rpm max. I'd like to change the crank to a stronger piece but i'm not sure what I need. Would a Scat steel crank be ok at this power level or do I need something else? Second Question- Rods. I currently have Scat H-beams with ARP 2000 bolts. Adequate? Or should I step up to something like an Oliver piece? I guess I should mention that this is a Drag Race only engine, launching off a transbrake (4000rpm). Thanks for any input.

I Don't Know What Lenght Rod You are Running.

I Also Don't Know if the Molnar's are Any Better Then Scat or Eagle.

Here's a Set of 6.7's if You Want to Look Into Them Any Further.

You Would Think From The Price, They Must Be "Special"

Below is What's Left of The Nice Cranks and Rod Combo's

https://www.ebay.com/itm/174294726879

https://www.ebay.com/itm/225359612409

Thanks for the info. My engine only had right around 250 passes on it. It uses 6.8 rods and i’d really like to keep what i have but if theyre not up to the task i’ll buy whats needed. As far as lifters I really like the BAM DLC pieces although I think i’ll have to stick with .875’s. I cant get too carried away with my budget. I was hoping i could get the 50-75 Hp that i’m looking for with basically a cam change and a few more cubes. I’m definitely going to be running a race gas mix this time. I think running it on 100% pump gas is how I hurt it this last time around. (Burnt a piston) So I could go with some more CR as well. The car is really going to haul ass after this rebuild.

650jetmech wrote:Thanks for the info. My engine only had right around 250 passes on it. It uses 6.8 rods and i’d really like to keep what i have but if theyre not up to the task i’ll buy whats needed. As far as lifters I really like the BAM DLC pieces although I think i’ll have to stick with .875’s. I cant get too carried away with my budget. I was hoping i could get the 50-75 Hp that i’m looking for with basically a cam change and a few more cubes. I’m definitely going to be running a race gas mix this time. I think running it on 100% pump gas is how I hurt it this last time around. (Burnt a piston) So I could go with some more CR as well. The car is really going to haul ass after this rebuild.

If You are Going To Buy Race Gas Run Some Compression.

I Would Keep It Somewhere Between 12 and 14. 12.5/1 Would Likely be My Compromise.

I sent You a PM on Non DLC BAM's but, They are .904". Might Get a Good "Make Offer" Deal on Them, But Then There's Machine Work, Plus They are OffSet.

^ On My Junk, I am Going To Try and Stay Away From a Roller Cam.

If I Go 545-557 or Bigger, Then, Yea, I'll Likely Bite The Bullet.

That's Away's Down The Road Though Unless I Hit The Lotto or A Money Train Crash's In The Yard, LoL.

I Bet Your Car Did and Is Going To Haul Ass Even Faster Now.

I With You All The Way on That Budget Thingy.

Thanks for the PM. I just dont think i’ll be able to swing the price of upgrading to a larger lifter. This engine will be going into my 69 Mustang which ran a best of 9.68@139 in the 1/4 last year. My goal is to get it into the 9.4-9.50 range at 140 plus.

650jetmech wrote:Thanks for the input. Valvetrain upgrades are also part of the plan. The new cam is a Kaase part. 272/280 @.050 .774/.770 with my 1.8 rockers. At a minimum I want to change over from my Comp 836 lifters to a bushed lifter from BAM or equivalent. Were also talking about Ti retainers and anything else I can do to lighten the valvetrain within my not to large of a budget. I’d like to crack 800Hp on mainly pump 93oct with a little bit of race gas. So I was hoping to keep the compression ratio around 11:1 with my AFR 295 heads. Other than that we’ll be adding a windage tray and maybe modifying the front sump pan with a small kickout. Its topped of with an AFR intake and an 1150 dominator. So I think i’ll make my Hp goal but I also want a reliable piece that will go 300-400 passes before another refresh.

I wonder if Anyone has matched (If You Could Even Get One) a TFS Mafia Intake up to The AFR Heads, Just to See What It Does?

I am Not Talking about Cutting The Heads, Just The Intake. Leave Any MisMatch There, When It's on The Head Side. Like Bolting an SCJ Intake on D0OVE Heads.

Your Car Looks Great. Glad You Came Back Around, It's Been Awhile.

I Hope You Get The E/T's You are After, I Suspect You Will

VP110 is not expensive for race gasoline and will survive 12.5/1 compression ratio.

Low compression in a strictly Drag Race engine is kind of counterproductive.

I was wondering if the Mafia manifold would fit these heads myself. But I’ll probably stick with what I have. As far as the CR goes I’ll talk to my engine guy about increasing it since we’re getting new slugs anyways. Anything else that you guys would recommend to increase the durability of this engine? I really appreciate the feedback.

if you plan on that many passes on an engine i would consider a custom cam with a soft ramp,like a drag and drive cam.kaase can have one ground for you.this way,lighter spring load would give lifters a longer life.also you may not need a bigger dia lifters,just bushed lifters.for sure the scat 4.500 forged cranks are nice and will last a long time.as for the intake not sure how the tfs fits the afr heads.my 598 has ported p51 heads and the tfs needs to be port macthed for sure.
i have a 69 coupe with a 572 but havent got it to the track yet.

650jetmech wrote:I'm in the process of redoing my 750Hp 521 and wanted some opinions from the forum. I currently have a Scat 9000 4.30 crank in this engine. I'm looking to boost the Hp level up to 800-825 and spin it up to 7000rpm max. I'd like to change the crank to a stronger piece but i'm not sure what I need. Would a Scat steel crank be ok at this power level or do I need something else? Second Question- Rods. I currently have Scat H-beams with ARP 2000 bolts. Adequate? Or should I step up to something like an Oliver piece? I guess I should mention that this is a Drag Race only engine, launching off a transbrake (4000rpm). Thanks for any input.

I really like the 4.3"/6.8" Combo. Especially on Small Bore Factory Blocks.

In your case, since you have a 4.3" kit and are getting new pistons, to boost your compression, I would be really Temped to go for a 4.5" Forged Crank at That Stage in The Game.

I would Also Stick with the Kaase Cam you selected, Since it is Drag Race Only, and Consider Lifter Changes or Rebuilds Just Part of the Deal at Your Level, To Go Faster.

Yes a Mafia Can be Made to Work. At The Lower RPM, Up to 7k Rpm a Little Mismatch is Sometimes Good to Keep the Fuel Charge Disrupted "They Say".

I See SR-71's in Your Future When Low 9's Is Just Not Fast Enough

I didnt mention it but this engine has an Eliminator sportsman block. So I could go pretty big. But since the car can only fit a 10.5” slick I was thinking that I should stay with the shorter stroke to keep the low rpm torque at a manageable level. I already have had issues with it spinning off the line sometimes. I made a rear gear change last year which really seemed to help that. Anyways thats why I wanted to stay away from the longer stroke. But I realize that increasing the cid to 557 or more would make it a helluva lot easier to make my Hp goal and keep the max rpm down which would be easier on parts. So i dont know which way to go really. And I dont want to overshoot that 800-825Hp goal and end up with a 900Hp monster. Thoughts?

supervel45 wrote:

I See SR-71's in Your Future When Low 9's Is Just Not Fast Enough

 I dont know man, a mid 9 second ride is about all I can handle I think.

650jetmech wrote:I didnt mention it but this engine has an Eliminator sportsman block. So I could go pretty big. But since the car can only fit a 10.5” slick I was thinking that I should stay with the shorter stroke to keep the low rpm torque at a manageable level. I already have had issues with it spinning off the line sometimes. I made a rear gear change last year which really seemed to help that. Anyways thats why I wanted to stay away from the longer stroke. But I realize that increasing the cid to 557 or more would make it a helluva lot easier to make my Hp goal and keep the max rpm down which would be easier on parts. So i dont know which way to go really. And I dont want to overshoot that 800-825Hp goal and end up with a 900Hp monster. Thoughts?

with bigger cube engine you can run less rpm.parts will last longer and make more torque.besides i think the 4.300 and 4.500 cranks are the same prices.and if it makes to much hp just put a smaller carb on it.

with bigger cube engine you can run less rpm.parts will last longer and make more torque.besides i think the 4.300 and 4.500 cranks are the same prices.and if it makes to much hp just put a smaller carb on it.[/quote]

Definitely something I need to discuss with my engine guy. I’m just not sure which way to go.

650jetmech wrote:I didnt mention it but this engine has an Eliminator sportsman block. So I could go pretty big. But since the car can only fit a 10.5” slick I was thinking that I should stay with the shorter stroke to keep the low rpm torque at a manageable level. I already have had issues with it spinning off the line sometimes. I made a rear gear change last year which really seemed to help that. Anyways thats why I wanted to stay away from the longer stroke. But I realize that increasing the cid to 557 or more would make it a helluva lot easier to make my Hp goal and keep the max rpm down which would be easier on parts. So i dont know which way to go really. And I dont want to overshoot that 800-825Hp goal and end up with a 900Hp monster. Thoughts?

Sounds Like You are Trying To Talk Yourself Out of What Would Be Almost Free HP at This Point (Since You Are Buying Parts That Cost About The Same)!

Snap Out of It Man.

Elimiator Block, Nice. There's Half of Your Reliability Right There.

Gears are Cheap.

Tighter Convertors Not So Much. Still Deals Can Be Had

You Want It To Last Longer and Be More Reliable, More Cubes and Less RPM is The Whole Point of Running a Gas Hog Big Block in The First Place, At Least To Me.

Don't Fear The Reaper, Go For 8's It'll Be OK

PS: Check Your Mail

650jetmech wrote:Thanks for the info. My engine only had right around 250 passes on it. It uses 6.8 rods and i’d really like to keep what i have but if theyre not up to the task i’ll buy whats needed. As far as lifters I really like the BAM DLC pieces although I think i’ll have to stick with .875’s. I cant get too carried away with my budget. I was hoping i could get the 50-75 Hp that i’m looking for with basically a cam change and a few more cubes. I’m definitely going to be running a race gas mix this time. I think running it on 100% pump gas is how I hurt it this last time around. (Burnt a piston) So I could go with some more CR as well. The car is really going to haul ass after this rebuild.

Did You Look Into These?

I don't know much about them and they are Offset Also.

The Feedback deal looks like only a slow shipping problem across The Pond, and may not even be his fault.

Just Passing them along, for your consideration and all.

Happy ThanksGiving

https://www.ebay.com/itm/385982050316?hash=item59de52b00c:g:NDoAAOSweodk3dVa&amdata=enc%3AAQAIAAABELqzGq3JLlXViBqudfw5J7yBuzpJ1stzC626etmW5NESHlnz8%2BIJRKQRvJLo6wEnIqiukO1nec%2BCpVur%2BftpeZBB6y6od6kmnxMheVumkhKIwfmJdHoAvhqneTpjFiXOcdX6kX7cDQLAn1sbuVPKQhN4mt3DqE%2FVrxHdnjDpdVFYZIXlSyJVqGIYtHU2iUJ62%2B3BP20w2FCOKHsDcjecJmFjsWHSpFVPyZdFx9IVZK9aVQTiHTgECauZprw3YQUuQRCoVloOKBIk1rRsV8ZnMi%2FWTBY4x%2FgUqvGRRFV5CxXtXfKGX84b78d1GasgmQ6ADWM51XMkXd41NzDaIFMe7Mg1XHyhRm%2BS%2F6ms2R%2F7s4k5%7Ctkp%3ABk9SR7TC4t__Yg

No I hadnt seen those. Supposedly my engine guy has a line on the BAM lifters so i’m hoping to go that route. I’m still waiting for him to give me a teardown report so we can discuss the plan for this new and improved engine. Thanks to this forum i have a couple things that i want to address with him now. Like increasing the CR and 4.3 vs 4.5 crank. I’ll post the build plans after we put something together. I’m not in a super big rush because I’m still saving up the cash to cover this.

supervel45 wrote:Don't Fear The Reaper, Go For 8's It'll Be OK

Nope, I’m not going that crazy. I’m more focused on making a deadly consistent bracket car here more than I am chasing a certain ET. I’m finding out that trying to put down this much power on a little 10.5 tire in the middle of the summer on a not so perfect track is tough! My chassis isnt setup to run in the 8’s anyways. Btw, Happy Thankgiving to you aswell.

650jetmech wrote:

supervel45 wrote:Don't Fear The Reaper, Go For 8's It'll Be OK

Nope, I’m not going that crazy. I’m more focused on making a deadly consistent bracket car here more than I am chasing a certain ET. I’m finding out that trying to put down this much power on a little 10.5 tire in the middle of the summer on a not so perfect track is tough! My chassis isnt setup to run in the 8’s anyways. Btw, Happy Thankgiving to you aswell.

I was Kina Just Messing with you JetMech on The 8's Deal.

With a Bracket Car That is Slowed Down From it Fastest E/T Should be Easier to be More Consistant, In My Opinion.

Save Up Some Funds and I am Sure Your Engine Will Turn Out Fine and Get You Were You Want To Be.

PS: I Remember When Lem Hooked Up Ritcher and The Grande with The Super Mill. It Was Too Much for His Chassis and I Guess He Took a Break from Racing After That.

^ So Point Takin

supervel45 wrote:

650jetmech wrote:

supervel45 wrote:Don't Fear The Reaper, Go For 8's It'll Be OK

Nope, I’m not going that crazy. I’m more focused on making a deadly consistent bracket car here more than I am chasing a certain ET. I’m finding out that trying to put down this much power on a little 10.5 tire in the middle of the summer on a not so perfect track is tough! My chassis isnt setup to run in the 8’s anyways. Btw, Happy Thankgiving to you aswell.

I was Kina Just Messing with you JetMech on The 8's Deal.

With a Bracket Car That is Slowed Down From it Fastest E/T Should be Easier to be More Consistant, In My Opinion.

Save Up Some Funds and I am Sure Your Engine Will Turn Out Fine and Get You Were You Want To Be.

PS: I Remember When Lem Hooked Up Ritcher and The Grande with The Super Mill. It Was Too Much for His Chassis and I Guess He Took a Break from Racing After That.

^ So Point Takin

Oh I know you were just kidding. But that is really the reason why I’m hesitant to go too big on the engine size. I’m guessing the new combo will make around 1.5 Hp per cube. Reasonable right?  So If i get up into the 545-557 cid range i could easily blow my Hp target by alot. But we’ll see. I’m not an engine builder. Just a guy who likes to blow alot of cash on engines.

JetMech., Check With Mike on Your Parts.

He Has Some Decent Deals on The Molnar Stuff, It Seems and Likely Some Good Piston Deals.

https://www.460ford.com/threads/molnar-4-300-stroker-cranks.251621/

Don't Know if You Saw These

4.5" Forged Molnar

https://www.ebay.com/itm/225359612421?hash=item34787aca05:g:9vsAAOSwFR5ePEqg&amdata=enc%3AAQAIAAAA8OKOIC3MKKoT1au9kks%2BXj6yMntgAhcb3t7cYCko7ODmSFNwm5rw26RIDjM94fHgKUxbPBp8D1DNsQDxe1kfJZa7HxUmH4EfKIQ0zX5WCoqKdl8Fa7mCCWYjdwf%2BmYT%2FevXLSei2P%2BODX2caHamtAIve4PBDY73BU3L9wxmkdg%2BG6k%2FPKuv2EhV5%2BraRS93XcHJ4JBmDtJqv%2BQr%2BqvCxt6i%2FDbnOdpfXYF%2BEG6%2F1A9%2F3oFNnqDF%2BEucQAAq3zXej66Nu8AmC9F8jbZfM3b7%2BInZs6VlHn2%2Bt8pFP2OdEOlxYoUhNEZsx2STKCnkoDOY1tQ%3D%3D%7Ctkp%3ABk9SR67bvIaAYw

4.6" Forged Molnar

https://www.ebay.com/itm/266089928474?hash=item3df432171a:g:9vsAAOSwFR5ePEqg&amdata=enc%3AAQAIAAAA0P03HhUzL7SALE5LE2YHvbCZ3ePJIw67BHxQ%2FQRyxw9QE%2FNMBb%2BwXVY8asxEo7qR4Uubqg%2FPU7dtGU01%2BoICGZhDg3Kr5eviCWZbKVqTUHlEMvLWnelpy8afUXEyJdVUg%2FHqRJkAk2s8zpVDaRAmP%2FeG7JHcDsW2Kbmu5YqqGCEn99rTc0GnzAdB1MNkbDRVKaaGd8qVpRotRA5jG6h%2F4%2B15ksVp7pn9R12%2FhDprg5JUq8Tpv1tbqJmb6j8IcbLmWBO7iC1kJSSBtOf0yZGKXPc%3D%7Ctkp%3ABk9SR67bvIaAYw

6.8" Molnar Rods

https://www.ebay.com/itm/225359612429?hash=item34787aca0d:g:8QQAAOSwn~BeJdjq&amdata=enc%3AAQAIAAAA0FG6bZGBXILqTWDjuI%2B10x6gcNXXXXTYVJf4y9gX1Lvsj%2FFq40M1%2FODrG4wCkqTcrgKKNc9443sCei8x%2BthX76T2t3Mo7wa8TG4YGZmX21bGtkY3r5iey34PUR0%2FrfhpYSIBSlRDqpLR2CUY5vfCkhWKT%2BYAkh16MiBKEbc9pqEF%2BqGyGSSfcKc%2F6hH%2Fd6AMjUgNnMU0yCLzfHhXi8BGH016px9tb8i%2Bl%2BgUUyIlj%2FE%2FgGS3Tf6RJ3kgrAr3dT%2BipPai67qXTqd0d%2F8oMcPt6tw%3D%7Ctkp%3ABk9SR67bvIaAYw

^ Be Careful with This "Stuff"! Make Sure It's In Stock Before You Order, Lot of Funk Going on These Days.

Do You Have 75cc AFR's

Interesting Pistons Below if You wanted to go .080" Over and Would Put You in The Mid 12/1 Range with a 75cc Head. Like 12.8/1 4.3" .005" in The Hole 75cc at Say 5cc for Valve Relief's and a .041" 4.5" Head Gasket.

Downside is The 5/64" Rings I Guess. They are Dual Valve Relief Also. Not Sure on The AFR Pierce Point for Them Either. They Do Come With The Oil Support Rings, Also.

Might be Better to Spend a Few Hundren More for Some 1/16" or Metric Rings and Pistons

Price is Not Too Sky High at Least.

https://www.ebay.com/itm/232461891203?hash=item361fcef683:g:jAsAAOSwR7lavBgQ

He's Selling The .030" Versions For Under 600 Bucks Also, Now.

https://www.ebay.com/itm/232439034215?epid=703055167&hash=item361e723167:g:JKMAAOSwoGNavBcA