Mustang and Ford Performance Forums banner

Build in Process, JRgoffin's Build Thread has Been My Guide Thus Far

15K views 70 replies 8 participants last post by  Jerry1200 
#1 · (Edited by Moderator)
My Setup:

Please remember this is sort of a make shift set up for time reasons, I want to hit the track before winter, I'm not pulling the motor or removing the heads until winter. Also keep note that I understand what I'm doing is probably building a time bomb. That in mind my tuner is old very wise and conservative, I'm thinking I'll tune it on VP Q16 to be extra safe and may God bless my piston rings.

All parts are sitting here unless I say otherwise.
What I need help installing:
Comp stage 3 cams, I already changed the springs & retainers and I have the ARP cam bolts you guys mention.

Cloyes adjustable timing gears & chains,
I bought every cam degree tool listed in Jrgoffins thread, his thread is AWESOME!, but I'll still need help degreeing the cams, last time I did the Ford GT cams I just did them straight up, didnt degree them. the guys at Comp Cams didn't really say where these cams need to be degreed at. Advice is welcome!!

Ford GT rockers, Question right away is do I degree the cams with a stock rocker and then install the GT rockers?

Pass side secondary chain tensioner from James at Cobra Eng, Seems like a simple swap.

Arp Crank bolt? or can I stud it? I have read Ed's awesome crank snout stud thread, but I cant do all that machine work right now. Also I need to put the stock crank pulley & cage back on, so the stud would have to be shorter. If you guys can offer part #'s for a better then stock crank bolt solution that would be great.

Torque spec's: why cant I ever remember this stuff? cam bolts 125lbs? crank ummmm ? cam cages? timing chain tensioner bolts? lower intake? blower? you know I had all this written down before, would of been smart to safe that info lol.

Whipple 4L, yep its sittin on the table here, Thus the reason for the stock crank pulley going back on.
Any advice or tips or things I should watch out for with a whipple would be appreciated. Thinking I can run 23-25lbs of boost with lower Intake air temps then my eaton stage 9million, I was spinning the living Sh-- out of that eaton, even with the killer chiller I have intake temps were higher then desired.

The rest is little stuff like cop's & ignition booster.

Blower belt tensioner recommendation, was gonna order a Thump RRR, but Ive heard the pulley they sell with it has a lot of drag. is there a different pulley option for the tensioner?

Going Auto is a must to win
Th400 with brake needed, I have a reid case and JW bell, need a trans builder thats not a quack and takes 2 years.

why cant I upload pictures to post in thread? keep getting an error message.

Ok guys more later, will be wrenching the next few days,
thanks for taking the time to read this.

Jerry
 
See less See more
#2 ·
Welcome aboard Jerry. I have edited your post to remove the nontechnical commentary. It is not that we don't want it, we just don't want it in technical forums like this one. In fact we provide a forum dedicated to just the type of non technical commentary you began the thread with. It is our Bar Forum.

With respect to your build plans, the use of a 4.0L Whipple on an engine that has not been properly prepared for it can result in massively destructive events that have nothing at all to do with tuning. The most obvious one being ripping the snout off the front of your crank and literally totaling everything below the rocker covers.

Now having said that, if you just have to put a bullet in the chamber and pull the trigger there is no one more qualified to make that decision than you - because you will be writing the checks for all the broken parts. I would encourage you to hold your fire, dig into Joe's thread because it is nothing short of massively excellent for build practices along with how to stuff and then look at some of the threads for the higher powered vehicles that lean towards the race track specific style of build for camshaft and fuel system help.

As you progress through your build you will get commentary from a number of guys on the site (myself included) with their valuable first hand, been there done that sort of experience so you don't have to write checks discovering what they already know.

Take your time, keep your powder dry and don't shoot till you see the whites of their eyes ...

Ed
 
#3 ·
Thanks you Ed, I appreciate the fair warning and respect your knowledge of these motors. but I will risk it to win, that said we will for sure see if it lives. I have had experience back in my fox days with a XX trim vortech cog belt breaking and ripping the water pump off the motor and as the car rolled to a stop the balancer came rolling out from underneath, I was in that car when it happened but it wasnt mine. I'm no stranger to carnage.

My fuel system should be plenty, returnless system with 2 walbro 465gph, big lines rails proregulator, ID1300 injectors.
Ignition has a JMs box and weaponx gen2 coils.

Things I feel I are working in my favor for this thing to live,

#1 most important, I'm not stupid LOL

#2 My car is light, it was 3105lbs with me in it last fall and I'm 210. Also have a lightened rearend gear and drilled axles, less spinning weight.

#3 Serpentine belts are more forgiving, Metco 6lb coming off & Stock crank pulley & cage going back for more crank snout stability, today I ordered an ARP damper/crank bolt, Ive read different torque specs, Any recommendations?
Would love to do Your stud crank snout set up, but that will have to wait untill this winter.

#5 will try to keep the upper pulley size to yield no more then 23lbs of boost, starting with the 3.5"

#6 Will only use the foot break, no trans break useless its absolutely necessary, and I will not be peddling it if it spins, I watched many of my friends destroy their blower setups by getting out & back in the gas hard upon tire spin.

Minutes ago I had a wrench in my hand about to put in the new passenger side cams, Back to good ol jrgoffins build thread to look up the torque specs for the cam bearing girdles.

:grin:
 
#6 ·
Couple of thoughts here, Jerry.

First I would point you at a pair of threads in the TToC called OK So Where Do I Set My Cams? and Cam Selection & Phasing - The How's and Why's. They are under the Engine section in the TToC and will give you a pretty good grounding.

With respect to fasteners and washers make your life easier and down load the pdf doc in the A Complete ModMotor ARP Fastener Listing thread in the Engine Building section of the TToC.

When you are done with that go over to the Secondary Cam Drive Chains - One More Time thread in the TToC under the Engine section.

You will find a lot of other excellent threads and information in the TToC that are worthwhile reading before spending hard earned dollars on various parts and or building the engine w/o the beneficial experience of the guys who have gone before you.

Parting comment on the cam washers, they are only needed for the intake cams with the Cloyes kit. The exhaust cam gears have the washer built into the adjustable hardware and should not have another installed.

Almost forgot were the Ford GT cams you previously used from the Ford GT(40) Super Car or were they from a GT500 engine?

Ed
 
#7 ·
I will be looking through those threads you suggested, thanks Ed..

In 2011 I installed the Ford GT super car cams. I bought the ford OTC Cam tool kit and installed them straight up using all the stock timing marks on the stock gears and chains. Car made 570whp with the Ford GT cams on a ported eaton that I had Steig do his over diven interal gears, used a stock upper and 6" lower. This was an improvement from my previous 495whp setup of stock 03 cobra cams and just a 2.80 upper pulley ported eaton (with no internal gear obviously).

The cams I'm installing Now are Comp Stage 3
Intake Duration at 050 inch Lift: 238
Exhaust Duration at 050 inch Lift: 240
Duration at 050 inch Lift: 238 int./240 exh.
Advertised Intake Duration: 273
Advertised Exhaust Duration: 275
Advertised Duration: 273 int./275 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.475 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.450 in.
Valve Lift with Factory Rocker Arm Ratio: 0.475 int./0.450 exh.
Lobe Separation (degrees): 116
Computer-Controlled Compatible: Yes
Grind Number: XE274BH-116
 
#8 ·
Don't mean to be a naysayer but you might just find the Ford cams phased differently than "straight up" will perform better for you. The comps are pretty big cams and will work in higher boost (30psi and higher) implementations but below 30 psi the Ford cams, properly phased, are pretty tough to improve upon.


Ed
 
#17 ·
Don't mean to be a naysayer but you might just find the Ford cams phased differently than "straight up" will perform better for you. The comps are pretty big cams and will work in higher boost (30psi and higher) implementations but below 30 psi the Ford cams, properly phased, are pretty tough to improve upon.

Ed
Ed, when you say "Ford Cams" do you mean the factory 03 cobra cams or the ford GT/GT500 cams? I know that some use the 98 cobra cams as well, I can't remember if its the intake or exhaust came.
 
#10 ·
Tony's point is spot on, Jerry.

I meant to comment about the Weapon-X coils and got interrupted. When I returned, my coil comments completely slipped out of my consciousness, probably early onset brain fade!

Your stock coils are good for some pretty impressive power levels as Tony already suggested. If you decide at a later date to go to an aftermarket ECU the options for coils that you will have available will allow you virtually any coil you might want to use. Today the most popular are the 100+ millijoule LS coils from GM. To put those coils in perspective, Ford's OEM cops put out about 20 - 22 millijoules. big difference!


Ed
 
#18 ·
All three turn out to be pretty impressive cams when properly phased Bobby but not the way Ford suggests. The sleepers in the group are the stock 03/04 or 96/98 cams. Phased correctly, their power production characteristics and numbers will absolutely stun you!


Ed
 
#27 ·
All three turn out to be pretty impressive cams when properly phased Bobby but not the way Ford suggests. The sleepers in the group are the stock 03/04 or 96/98 cams. Phased correctly, their power production characteristics and numbers will absolutely stun you!

Ed
The 03/04 cams are the same as all the other low duration low lift 4v cams. The 96/98 offer the most duration (intake side only) plus the larger cam bolt. The 99 Cobra is next then the 01 Cobra.

The GT/late GT-500 cams offer more lift but are tested with less duration than even the generic 4v cam and overall are not at all an upgrade.

While you can make good power with stock cams, you'd be leaving a massive amount of power on the table by not using properly spec'd cams.
 
#19 ·
Can't thank you enough for this info Ed!! I will need a few to digest it all. Lately Ive had little time to wrench on it, these are my busiest months at work, but I should be into the cam degreeing process full tilt this by this weekend.

Was wondering if they fixed the site yet so that I can post a few photos.
 
#20 · (Edited)
The answer to the site fix is I was just beating up the problem with the guys last night. As of right now it is not fixed but I am hoping for a resolution shortly.

With respect to the Cams stuff before you start the process we should talk. Without the ability to attach pics etc I can not show you what you need to see before beginning the job. I will PM you with another way to see the info that does not require ModFords image display capability.

Ed
 
#21 ·
Curiosity is getting the best of me. Test pic:
 
#22 ·
The problem is that it is not consistent across browsers or computing platforms, Josh. Some work, some don't and others are intermittent. To make matters worse some folks have lost all or some portion of all of their album pics. The current release of vBulletin appears to have some significant operational problems that to date have been impossible to understand let alone fix. Hopefully this is about to change.

This is what you see when I upload the pic you just posted in your thread;

Pretty amazing, huh?

When I go to the URL you sourced the pic from and attempt to upload from it as you did this is what happens;

Instead of a pic I get a message that the file is invalid! Now this is the exact same file you uploaded without error!

And of course, 'there in, lies the rub' (a misquote from Hamlet's soliloquy about suicide).

While we are aware of the issue and have been working it diligently we are still awaiting the fix ...

Ed
 
#23 ·
That is quite interesting. I have to un-check the "Retrieve remote file and reference locally" box when I link the image otherwise it says it's an invalid URL.

FYI: I am using a chrome browser on a severely under-powered, heavily regulated, Windows 7, government computer.
 
#24 ·
I've duplicated the problem on Safari, Firefox and Chrome, Josh. I have not tried other browsers like Opera etc. I have also duplicated the problem on Windows platforms w/64 bit Win7 in virtualized environments (VMWare) as well as native execution on Dell laptops w/64 bit Win7. At this point it does not appear to be platform, OS or hardware specific. It is challenging, to say the least.


Ed
 
#25 ·
I just tried un-check the "Retrieve remote file and reference locally" box and in fact the URL upload does work when it is unchecked;



But we still have all the other issues yet to resolve ...

Ed
 
#26 ·
I am glad it worked for you. It's not a complete fix, but a step in the right direction anyway. Now I just need to use it to contribute to the site.
 
#28 ·
You hit the nail on the head with respect to the general pecking order of the OEM Cams Cody.

The cam choice that works best with any particular engine is tied to the engine displacement, head performance (flow characteristics) and boost more than most other variables.

One of the challenges all the builders wrestle with is the head flow, engine V[SUB]e[/SUB] and boost. Consider for a minute a cylinder @ 1 BAR manifold pressure and 100% filled at BDC. Suppose you did not close the intake valve until the piston was 20% of the way up the cylinder.

If the cylinder was 100% filled at BDC and you decreased the volume by 20% by raising the piston 20% of the way up the cylinder before closing the intake valve then you raised the in cylinder pressure by the same percentage. What would happen with a 1.2 Bar pressure in the cylinder and a 1.0 Bar pressure in the intake port? If you guessed that the charge would be pushed back into the intake manifold - you are correct.

Specifying a cam for a particular build (when done correctly) may very well not look at all like a properly spec'd cam for the same engine design but different operating parameters and (somewhat obviously) engine spec's. As luck would have it the OEM cams, all of them, find their way to the top of different power production heaps depending on some of these design and build variables.

An engine with not as good an upper rpm head flow behavior might conceivably benefit from a later intake valve closing point to provide more time to optimize cylinder fill (V[SUB]e[/SUB]). Whereas the same engine with improved upper rpm intake port performance would not need to crutch the head flow with the late closing intake. Similar but different dynamics impact intake valve opening points and not so surprisingly exhaust side dynamics also.

The problem when you set out on the custom cam search is that there is a fairly good supply of experts who want to provide you a custom profile for the engine. The really interesting part is that all the 'experts' custom recommendations usually turn out to be different and in fact can change year to year - even though the engine didn't! The exception to this is obviously the two or more 'experts' who both recommended the same profile(s) only for you to later discover that their 'custom' profile(s) were just another cam set in the particular cam grinder's cam profile inventory that both 'experts' decided they liked.

Ignoring for a moment the two or more 'experts' that recommended the same identical 'custom' profile out of a cam grinder's cam profile inventory, the pregnant question is Why, if the all the other experts are correct, are all their recommendations different? Presumably a custom cam recommendation for an engine would be best because it optimized the engine performance i.e. torque and therefore power. How can all the custom recommendations each comparably optimize the engine's power output if they all are different?? And to steal (and slightly modify) a quote from Shakespeare's Hamlet, therein lies the rub!!

BTW the guys who snatched the same profile off a cam grinder's profile inventory list are every bit as unreliable as the guys who gave you the wild ass guesses that were all different. The only difference between the two different classes of 'expert' is one is lazier than the other.

Ed
 
#29 ·
I had the pleasure of speaking with "The Man" last night for a good while, Ed gave me a real schooling on the cams and how they work in these motors. Ed I cant thank you enough for taking so much of your time to show me everything.
For the newer guys on here I make this short, I've been doing this stuff since 1998, Ive been around a lot of fast cars, Ive been studying engines a long time, half my friends cars were in 5.0 magazine, My crew even beat John Urist one time. I could go on and on, bottom line No one Ive ever talked to knows these Ford 4.6L Dohc motors like Ed does, not even close. Ed knows these motors better then Micheal Jordan knows basketball.

That said after being thoroughly educated by Ed I will say that I completely fell for internet hype and superstition bs and bought stuff I shouldnt have. I use to make fun of guys that bought what I referred to as "dummy magazine parts" and now I'm the goat, first time and hope its the last time. So its been one step forward & 2 steps back.

Ok rant over back to the build

Has anyone ever tried to re thread Ford GT cams so that the bigger 12mm ARP cam bolts can be used? My factory cam bolts are stretched in the middle real bad, I remember when I installed the GT super car cams the bolts would not even reach 50ft lbs, they just stretched.
 
#30 ·
Thanks or the props, Matt. You're embarrassing me. I just try to share what I have learned over the years so others don't have to pay again for the knowledge we have accumulated over those same years. No good reason to pay twice ...

With respect to the cams and retapping them for the 12mm bolts, as luck would have it, I have actually already done that. When I did it I tapped for 1/2" ARP studs. The 12MM Mini Cooper bolt will work very well also and it has a nice big fat head on it. There is a pdf file over in the TToC under the Engine Builds section named A Complete ModMotor ARP Fastener Listing that lists all the ARP hardware used to build a Modmotor. You will find the ARP part # for the MiniCooper bolt under the Cam Bolts section.

There are two ways to create an internal thread, one is to cut the thread and the other is to form the thread. The formed thread is like the rolled threads on the end of ARP fasteners. It is a very strong high precision thread. If you go the metric fastener route and use the 12MMx1.5 MiniCooper cam bolt, the thread forming tap will cost between ~$50 and several hundred dollars (for just one tap!) at MSC.

You have several alternatives the first is to use 1/2" ARP studs and a 1/2" thread forming tap. The taps are available from MSC again and cost from ~$26 to several hundred dollars.

If you go the SAE route and use ARP studs, the studs and nuts will cost you approximately $10 per cam with another around $8 each for two of the super washers. That means your fastener costs will come in around $56 for two cams and another say $40 for a mid range forming tap plus about $10 for a high pressure lubricant for the thread forming process. All totaled you will be in the tank for about $100 / $110.

If you go the MiniCooper cam bolt route you will be in the tank for ~$20 per bolt plus two of the super washers @ $8 each for a total of $96. To that add a midrange tap for ~$75 and about $10 for a high pressure lubricant for the thread forming process. All totaled you will be in the tank for about $180 / $190.

The big difference is the cost of fasteners and the cost of the thread forming tap. Both fasteners get torqued to 125 ft/lbs and have similar holding power.

The following drill and reamer sizes will provide you with a 70% thread engagement for both Metric and SAE solutions;

Because drills drill over size I recommend going one size down in the drill and reaming the hole to final size for threading. That means you need to add the cost of a drill and reamer to the above costs.

For the SAE thread the finished hole needs to be 11.77mm that means you will need an 11.77mm reamer. The drill size you will want is 29/64".

For the 12mm formed thread the reamer size you will want is 11.29mm. The drill size you want is 7/16"

The third and last alternative would be to use cutting taps for either the SAE or Metric thread. The cut thread approach will work but it is not as robust as the rolled thread alternative. That said the studs provide better service for the same reason head studs are better than head bolts.

Ed

p.s. The drilling and reaming should be done in a lathe along with the finish threading. The finished thread should be hand formed not machine formed only because there is no convenient way to reverse a lathe when the forming process has finished.

p.p.s. I highly recommend the Cloyes adjustable primary and secondary gears. The primary gears can be purchased separately from the complete Cloyes kit as service parts for around $255. See Joe Goffin's build thread for details. You will also need a Cloyes billet crank sprocket again available separately for around $40. The cost of the adjustable secondary gears escapes me right now but they were cheap compared to the other Cloyes stuff.
 
#33 ·
I believe the reason Matt is interested in the larger fastener mod is that he already owns a set of the FGT cams, Cody.

Ed
Ed You hit the nail right square, Ive had the Ford GT super car cams in my car for a few years now, very recently took them out to do different cams, basically because (to keep it clean) I am not a smart person.

Yes I already have purchased 4 of the ARP 12mm and 2 ARP washers as I also have the entire Cloyes adjustable gear set. I already drilled out the washers on a lathe to fit the ARP 12mm bolt perfectly, So I'm already invested in the 12mm bolt route. The 12mm bolt screw right into the brand new Comp cams set I have. But after Your lesson on cams in these motors they are going up for sale.

I will be looking to get that thread tap you mentioned so I can make these 12mm mini coop bolts work with the F GT cams.
 
#35 · (Edited)


Well I'll be damned it worked!!

So these are my cam bolts, easy to see the factory bolt stretched real bad.

I'll try to post some more pictures of my build now that I think I have this figured out.

Ed is this the thread forming tap you referring to for the 12mm bolt on the Ford GT cams.

https://www.mscdirect.com/product/details/70648381

only thing Im not sure about is the D6 or D11 thread limit tolerance ??
 
#37 ·
My point still remains, it would be cheaper to buy 96-98 cams than modify your GT cams. The GT cams are honestly about the worst cam choice possible, they have the weakest duration for some extra lift and require springs due to the lift. Our heads flow so well in low lift that the extra lift does next to nothing.

Secondly, no idea why you'd want to spend money modifying GT cams when you have a set of comp cams, if you feel the specs are too aggressive fine. But Ed is not saying that anything but factory is crap, he's just suggesting that when you add cams you do have to sacrifice something for more power. This is no different than any other aspect for more power, adding a larger blower increases IAT's more than a cam swap does (assuming they are installed correctly).

It is incredibly common to see 40-100rwhp from cam swaps depending on the level of build.

While there are companies that will just sell you a generic grind there are also 3/4 easily available fantastic cam specialists that will get you power.

No need to fear a cam, the problem is most people over cam their cars for audio aesthetics only.

I will not pretend to be a cam expert as I was posting in here a couple years ago to get more information and held off buying for nearly 1 1/2 years when I finally started to understand. The fist hand experience I've gathered has helped me make my choices, while I would never say I'm comfortable spec'ing someone a cam I can tell you that the days of cams not being worth it are long dead. If you have the engine apart you will kick yourself later if you don't do the cams now and have to drop the engine to do it later on.

To address Ed's comment. Of course different people spec different things, when I asked about pistons from multiple places everyone spec'd different pistons including you. Does this mean I should use factory pistons from the 03 cobra rather than gibtec or some other custom? No. When people call up a speed shop each one will suggest a different build path, a different power adder, a different intake, a different trans, a different suspension company. These are all choices we as tinkerers make and we must either educate ourselves or find someone we trust enough to be educated for us to make these choices. Cams are no different and should not be viewed as different simply because most people don't understand the process behind them.


Edit: If you are running a 4.0 liter blower what the HELL are you doing trying to use stock cams?
 
#38 · (Edited)
Edit: If you are running a 4.0 liter blower what the HELL are you doing trying to use stock cams?
Many reasons broski,
1. Power isn't a problem with this setup, how to turn it way down and not blow my **** up is more the problem. How do I only make 23 lbs and no more then 850whp with my setup and Not blow it up.

2. If you read my very first post I said its a temporary setup. Reason for that and really the only reason I'm doing this make shift set up is because Im in competition with someone, Someone I absolutely cant stand and will not lose too. I cant speak for everyone but When I have someone I have to beat, and money already bet I do whatever it takes with what money & time I have permits. I'm 38 years old, I mind my own business and ill be damned if Im gonna let a 22 year old punk with a ws6 firebird talk smack to me every day about how Fords suck, thats just the tip of if.

3. If I was doing this normally like a normal person doing it right the first time, I would of pulled the motor called Gibtec and Sonny Bryant or Wineberg and went to my engine builder with the teksid block and 05 aviator heads I have. But thats what a normal smart guy would do, I already showed my lack of intelligence on here when I rushed out and bought expensive cams that are really not good for anything but exhaust sound, Never said I was the sharpest knife in the drawer.

4. I'll let Ed tell you how those Ford GT cams stack up against the comp cams I have. I made 494whp with stock cams on my eaton setup, I changed a few small things put in Ford GT cams and E85 and I made 570whp on a very weak tune and my blower belt was slipping.
Ok I'll make you a deal Nightmare, if I can find a set of 98 cobra cams in the next 7 days I'll pick em up.

Matt
 
#39 ·


Instead of having this decorate my living room for the last month, I should of just slapped this thing on the top and not touched anything else, it all started with that secondary cam chain tensioner I got from James at Cobra Eng. One thing lead to another and here we are.
 
#41 ·
Hey guys, been a while, I'm still waiting for the machine shop to thread my GT cams for 12mm bolts, should have them any day now. In the mean time I ordered an oil pump from Boundry, showed up in 2 days, looks great went with the 3v pump. I am going to attempt to change the oil pump without dropping the oil pan. Unless anyone knows that this absolutely is not possible.
I'll post some pictures later, last Sunday I changed my rear cobra brakes to smaller mustang GT brakes so I could fit these 15x10 champion drag wheels I have with Hoosier 275 DR's. had to pull the axles to do it. The wheels look pretty good. One less thing to do later Lol.
 
#42 ·
Gents lets talk crank balancers/dampners. I'm in that "well might as well do it while its apart" sort of mindset. My thinking is that with the amount of stress a whipple 4L will put on my stock shortblock rotating assembly, any little thing I can do to improve bearing life and absorb vibrations is worth doing.
I see 2 options, ATI proformance and the well know Innovators West.
Ive had BHJ and ATI balancers on other cars. ATI is a quality product, obviously not as pretty as the Innovators piece. Looks are the last thing I'm worried about. There is a $400. Price difference between the ATI and Innovators balancer. Ive read what I could about the dampning technology of both products, the Innovators W balancer seems a little more advanced using cluches & liquid. So the questions in my mind are what am I gaining over the stock piece? And is the Innovators worth the coin? I'd be going with the OEM style because I'm using the stock crank pulley cage.
Would like to know what you more experienced guys are using.
 
#43 · (Edited)
A number of years ago, Jerry I was shopping for aftermarket balancers for a modified blown 4.6. I looked at a huge number of suppliers and asked questions like how do they determine the proper damper characteristics for a particular engine. For example look at the size of a GT500 damper, an 03/04 SVT Cobra damper and a Mach I damper. An understatement would be that their sizes vary widely.

When I asked the manufacturers about how to properly design a damper only two had credible answers - ATI and BHJ! As I dug deeper only BHJ would share the engineering. I have attached the paper they shared with me, in pdf form, to the end of this post. To the extent I could determine, I believe ATI does the same engineering for their dampers although they treat the engineering as more of a trade secret than the BHJ guys do. That said I believe their product is comparably well engineered not withstanding their reluctance to share written doc - their answers to questions I had were clear, correct and quickly provided.

I ended up going with BHJ because I needed a custom design with features that ATI could not conveniently fit into their build model and BHJ could. This is what the damper I designed for my use looks like;



It does not use the OEM lower cage and secures the lower blower drive to the damper hub so the damper can still dampen crank torsional movement. The damper is available for either a stock 1.25" diameter snout or a more robust 1.400" diameter snout that I built my crank with.

I highly recommend using the crank stud instead of the OEM bolt on either an OEM crank or a billet crank. There is a write up on how to do this in the TToC (Terminator Table of Contents) sticky at the top of this forum. It is in the Crank Tech I and Crank Tech II threads.

After the damper you will need a drive hub for a Lower Metco style pulley. This is what the drive hub I designed looks like;



The doweled front snout is for an external wet sump pump (which I use) or it can also be used to drive a dry sump pump.

You may or may not choose to pursue this type of a solution. If you do choose this solution BHJ is the only choice - no one else will do the custom work or at least would not when I was buying. If you choose to follow the more typical OEM style drive path then either ATI or BHJ have very credible product offerings and can explain the engineering behind why they did what they did. When I was sourcing dampers no one else could. I suspect that is still the case today.

Here is the BHJ white paper;

Ed
 

Attachments

#45 ·
Awesome information Ed, love the BHJ write up. I used an ATI on a foxbody T trim vortech pushrod set up, then switched to a lighter BHJ when my motor was internally balanced and I was then running a turbo. Back then I used those because thats what I was told to use by my engine builder. Now days I care a lot more about the science behind why I'm choosing a part to bolt on.
I'm going the OEM route.
I'm seeing 2 part #'s for the ATI, seems like it could be sold as a damper and Hub is separate, Im not sure though.
http://www.atiracing.com/products/dampers/charts/damford.htm
ATI Damper part# 918044
ATI Hub part # 916584

Maybe I can just muster the coin for the BHJ, After reading the BHJ Crank torsion and dampers write up how could anyone go wrong using there product.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top