Help: Builing a Street 408

[donraye]

Hi all, I am just getting ready to build my first motor and would like some feedback from more experienced members on some component choices. I am ordering the small block already built and will need to know what heads I am going to use so that the builder will use the correct pistons to get that magic 10.5-1 conpression that will allow me to use pump gas but still have some punch.
This motor is for the street not for competition and I want the power to be biggest in the 2500 to 5500 range (or hopefully 2,000 to 6,000 range).
My head choices are limited by the total cash I have on hand for this project so the $2,000 plus goodies are out.
I have a choice of:
A: AFR 185s out of the box.
B: A fully checked, measured, and CNC ported set of Pro Comps in 215 or 230 cc runners. (before I hear all the yelling and BS about "Pro Comp Chineese junk" I will tell you that I personally saw a set of these very same CNCed heads in the 230cc runner size on a 418 stroker with a 750 Holley the other day turn in over 600HP on the Dyno here at Infineon!)
C: Another choice is a set of 195cc Dart Pro 1 Platinums (out of the box)
D: Lastly there is a set of Edelbrock Victor Jr. 210cc runner size out of the box.
I personally think all of the above EXCEPT the well built and fully CNC ported Pro Comps are probably too small for the 408 but some of you could have different ideas on that perhaps. The point is I can not spend more than $1,400 and change for the heads as that is the budget and the choices above are what that $ will buy.
The other big choice is a Hydraulic roller cam for this street or street/strip machine. I am thinking something in the .540-.560 gross lift is about right and I likle the new Comp Cams "Big Nutha Thumper" cam a lot (but some folks do not). There are 3 grinds in the "Thumper" line and that one seems to have the most power and it makes the power where I want it. I am open to any suggestion about a good retro roller cam or cam/head combination for this build.
I will be using the MSD ignition system and Edelbrock RPM intake off of my current 351 and the Holley 750 on it. I will also be using 1.6 roller rockers. The bottom end is all forged including the pistons.
Any help with ideas or combos that fall within the $1,400 max. heads and a good $700+/- street/strip roller cam/lifter combo would be appreciated. (The roller cam and lifters would have to be retro as this is an older block.)
My personal choice for now is the CNCed Pro Comp 230cc heads with the Comp Cams "Big Nutha Thumper" hyd. roller cam and lifters.
I want this engine to make at least 475 to 500 HP and 450 LBS of torque which should not be a problem I hope(?).
Thanks, Don

[olddog]

AFR 185 are too small. AFR 205 would be my pick. If not AFR 205, my second pick is the Edelbrock Victor Jr.

Comp offers a XFI series of cams designed for strokers. I have a dyo pull listed in a book with XFI 0.579 lift 236/248 duration and 114 lobe seperation in a 408, wth AFR 205 heads, and super victor intake. It did 560 hp @6200rpm peaked 532 ft-lb @4900rpm. From 3000 to 6500 rpm torque stayed above 425 ft-lb.

Also your intake seems too restrictive for a 408.

[Three Peaks]

Sounds very close to my build and here is the recipe I will use:

Vic Jr. Heads- 210 cc runners 1.6 Comp Pro Magnum roller rockers, 58 CC combustion chambers. The Vic Jr heads come with excellent springs good for up to .650 lift. The AFR's have had a reputation of coming with lousy springs which would need to be replaced to handle the cam you are discussing.
Weiand Stealth intake with Holley 4150 750 DP carb.
Comp Cams XE 292 cam or the XE 284 Cam.
Keith black dished pistons. Check his site for a calculator for the appropriate dish, but you should end up needing about 20CC of dish to accomplish 10.5 to 1 compression
My cam is a flat tappet, but this grind is also available in a roller version

If you are going to use the stock 302/351 roller lifters, you'll need to do a slight amount of grinding for the dogbones to set flat on the lifter bore tops and you'll need to drill and tap 2, 1/4-20 holes in the valley for the dog bone spider to mount. Be careful with these holes as they land right over the cam bearings. This will save you enough money to take care of some of your other ideas, IMHO.

The RPM is a close copy of the cast iron OEM intake and will limit your flows and your power range. For low end power I would opt for a dual plane intake like the Weiand Stealth or Edelbrock Air Gap. For higher end power, look at the Vic Jr Intake, which is a single plane unit.

The guy I got the cam and other parts from for my engine had this combo in his 408 and he reported that it got 515 hp at the flywheel.

Good luck with the project.

Bob

[bobcowan]

My engine is a 427 - only slightly larger than your 408. It puts 470 hp to the pavement, drives down the road happy as can be, and gets 20mpg on the freeway.

Heads: Dart Pro-1, essentially straight out of the box. I port matched them to the intake, hand lapped the valves, and installed COmp Cams beehive springs.

Cam: Off the shelf retrofit roller from Probe/Coast High, the last one one the list ( the "Biggest").

Lifters: Stock Ford with stock Ford spider and dog bones.

[donraye]

Hi all, Thanks fo all the info so far. I came across an incredible deal on a new fully CNC ported set of Pro Topline/RHS heads on a clearance sale at Livernois motorsports so I bought them today. They flow 303 on the intake and 227 on the exhaust at only a .550 lift. Livernois has a great reputation for their porting jobs and they use only the best components in their builds so i think i did a good thing. These were about half the usual $1,900+ on the sale. I got them for just $999.99 with dual springs good for up to a .670 lift, guide plates and studs. They have 64cc chambers with 2.02 intake and 1.60 exhaust stainless valves. They said that these heads were used in a lot of 408 and 418 builds they have done and performed very well.
So that is done and I am happy with a really good set of heads at a great price. (They have 7 sets left I think if anyone wants a pair they will go very fast.)
I made an error in stating my intake/carb in my original post, it IS a "Performer RPM dual plane Air Gap" intake and the Holley is a 770cfm dual pumper not a 750CFM as I stated before.
So, it's on to the cam question and I will check out all the ones you guys have mentioned but am a bit confused about the "retro" fit stuff. I think that some of the cams that have been mentioned do not come in "retro" roller version so if anyone could help me clear up that point I would be glad to learn about it. I will also be needing the "retro" hydraulic roller lifters I suppose? This would not be an issue with flat tappet cams but the rollers need to be "retro" I think since the block was not made for rollers originally.
Has anyone used, or know of someone who has used, the new "Thumper" line of cams from Comp Cams? They come in the "retro" type and in kits with matching "retro" lifters. Hopefully I will get the cam selection done as soon as I check out your various suggestions and confer with the guy who is building the short block for me.
The cam is a really important choice so I hope I get it right!
Don

[Three Peaks]

Don,
With a non roller block, you can use the link type lifters but the cost is pretty high. You can also use the original style Ford rollers and dog bones in a non roller block by drilling/tapping the holes in the block for the hold-down spider and grinding a very small amount off the valley around the lifter bores (in just a couple locations) so the dogbones will sit flat. Once that is done, you can use original style roller lifters, which are great lifters for around $100 for a full set brand new from Ford. Your engine builder should know how to do this if he has experience with Ford small blocks.

If you want to know which cams in the Comp Cams lineup are retrofit cams, just give them a call and talk to a tech. I'm sure the 284 XR and 292 XR are retrofit cams. I may have typed XE which is their Extreme Energy line instead of their XR, which is their Extreme Energy Retrofit line.

The Retrofit cams have a smaller base circle to accomodate rollers in a non-roller block.

The heads sound very nice. I've heard good things about the Pro Topline heads. Actually, they flow just about the same as the Vic JR.'s out of the box. But your price is great so good shopping job.

Looks like you are just a cam away from your target. Take a good look at getting a road race pan for that engine if you intend on doing any track time.

Bob

[olddog]

I second the suggestion to call Comp and get their recommendation. Tell them what you are building (heads, cid, and intake) and what weight car you are putting it into. Be honest about what your likes and dislikes on engine manors are. Be realistic about where (rpm) you want it to make good power. Then let them tell you the cam and what the power band would look like.

[Keithc8]

We do these engines all the time and have a lot of dyno feed back as well as real word use feed back. I can get any camshaft done in a restro-fit for you from Comp Cams for 299.00. We use a steel core on our cams to keep from having any gear wear problems on the camshaft that Comp has had on some of the standard cores, I know because I have replaced them. You can do a retro valley trey and guides and all you have to do is drill two 1/4 holes in the valley using the trey for a guide. You than can use the Ford Racing hydraulic roller lifters for 120.00, the retro kit is 49.00 so you see it gets you out pretty cheap and works just like the factory stuff. I have done a 1000 this way over the years. I can get you the Ford Racing indexable timing set that is a double roller for 69.00 along with pushrods and anything else that you might need. Feel free to call me at 870-246-7460 and we will get you a custom camshaft that will work great for you along with anything else that you need. Thanks, Keith Craft

[bobcowan]

Now that's a deal that would be hard to pass up!

[donraye]

Originally Posted by Keithc8

We do these engines all the time and have a lot of dyno feed back as well as real word use feed back. I can get any camshaft done in a restro-fit for you from Comp Cams for 299.00. We use a steel core on our cams to keep from having any gear wear problems on the camshaft that Comp has had on some of the standard cores, I know because I have replaced them. You can do a retro valley trey and guides and all you have to do is drill two 1/4 holes in the valley using the trey for a guide. You than can use the Ford Racing hydraulic roller lifters for 120.00, the retro kit is 49.00 so you see it gets you out pretty cheap and works just like the factory stuff. I have done a 1000 this way over the years. I can get you the Ford Racing indexable timing set that is a double roller for 69.00 along with pushrods and anything else that you might need. Feel free to call me at 870-246-7460 and we will get you a custom camshaft that will work great for you along with anything else that you need. Thanks, Keith Craft

It turns out that my short block builder called to ask me if I wanted him to select a "true roller" block or a "conversion" block for my short block build that he is starting on now. So I have a choice that I was not aware of when I ordered the build.
I would asume that I will tell him that a "true roller block" which will allow me to use a standard circle roller cam instead of having to use a "retro fit" small circle cam is the best choice so that is what I will tell him tomorrow unless anyone here can think of a reason to do otherwise.
I did not know I would have this choice when I ordered but since I do wouldn't it be best to use the later vintage roller block that will accept the standard roller cams?
If anyone thinks of any reason that this is not best, let me know ASAP.
I'm going to call Keith Craft tomorrow about grinding me a custom cam for my build since he was kind enough to offer his services which are famous for their quality and his expertise in all things Cobra and all things engine build. I'm sure he will tell me which block type I would be best with when we talk about my choices.
I want to sincerely thank all of you for giving me a lot of valuable information and setting me set off on the right track. I now have just about all the goodies I needed to start this journey and will keep all posted on the progress as it comes together. Since it is my first build at age 62 I'm sure it will be a slow and careful one, so don't expect it to get done in a week or two as many of you might be able to accomplish it. It may take a lot longer but the important thing is that I take enough time to be careful and not make mistakes by rushing something until I fully and thouroughly understand it.
I'm sure I will need lots of extra advice along the way from time to time and you are all a great resource for me and other Cobra addicts to call upon. This web site and these forums are a Godsend for guys llike me who have a lot of passion but only very little knowledge. Without this resource and the help of members like yourselves I and many others would never be able to do or even try to do the things we dare try and do with the help of this fantastic Cobra community.
Thanks! Don

[Clois Harlan]

I had that discussion with an engine builder this week and he recommended finding a 69-75 351 Windsor block because they are stronger and machine the lifter bores to fit. He also recommended the 408 stroker be internally balanced and be sure and use the ARP 2000 series bolts because some of the previous ones have failed. As far as heads he recommended the ARP 210 heads that Keith Craft has or as a second option a set of Victor Jr. Heads. 1.7 roller rockers and a single plane intake.

Now all that being said remember this is one engine builders opinion and he is going on his experience building engines for mostly race applications. One of our members her DL uses this guy and has had no failures at RPM's around 7500. I would look to Keith Craft if I were you because he has probably seen it all. I am sure he has even had some experience with the PRO heads from Austrailia you described. I have even looked at them on EBAY.

Clois

[donraye]

Originally Posted by Clois Harlan

I had that discussion with an engine builder this week and he recommended finding a 69-75 351 Windsor block because they are stronger and machine the lifter bores to fit. He also recommended the 408 stroker be internally balanced and be sure and use the ARP 2000 series bolts because some of the previous ones have failed. As far as heads he recommended the ARP 210 heads that Keith Craft has or as a second option a set of Victor Jr. Heads. 1.7 roller rockers and a single plane intake.

Now all that being said remember this is one engine builders opinion and he is going on his experience building engines for mostly race applications. One of our members her DL uses this guy and has had no failures at RPM's around 7500. I would look to Keith Craft if I were you because he has probably seen it all. I am sure he has even had some experience with the PRO heads from Austrailia you described. I have even looked at them on EBAY.

Clois

Hi clois, Well as for the block I talked to Keith Craft and to the guy building mine (who builds a lot of 408/418/427) and they both said while it's true the older blocks are stronger it is not a problem until you get well over the 600HP range then it is. Since mine will likely end up in the 550 or less they both said it was no problem.
As for the AFR heads (you said ARP but I think that you meant AFR) Keith has and uses the 205cc (not 210) ones a lot, but my heads flow every bit as well as those do and retain the stock exhasust port location so there will be no problems/surprises in hooking up to my headers in their present location. these RHS heads are great heads and just as good (many think better because they use better springs) as the AFRs.
On the ARP bolts and internal ballancing: Yes to both, it does have those ARPs and it is internally ballanced.
My Edelbrock Performer RPM dual plane intake is a very good intake and it is the choice in Keiths shop as well as lots of other 408 builders so I'm comfortable with that selection and my trusty Holley 770CFM double pumper. Not fancy bit it gets the job done.
I also ordered a custom grind cam today from Keith Craft and in a three way conference with him, his cam guy, and his engine builder we came up with what they think is both what I want and what works best form their experience with 408s. It's the engine builder's favorite 408 street cam but with a reduced separation (108 from 112) to give it more lope on the idle while not sacraficing any performance.
They all said that most people want cams that have way more lift than they should and that hyd. rollers are mostly "done" at 6000RPM (unless you go to heroic lengths to increase that in the valve train components and geometry), yet people seem intent on wanting cams that really would only be correct in a solid roller design not a hydraulic. "People want lifts that would really want make power in an RPM range above that of the limits of the hyd. roller" their engine builder said. So I listened to their advice and let them pick the cam they thought worked best (with my input about the "sound" of the idle) rather than going for that "BIG" cam in the sky routine.
Let's hope it turns out right!
Thanks! Don

[donraye]

A couple of other things I would like input on if anyone would.
One is about gear drive timing sets vs. double roller chains. I have three choices in this department as I see it.
1: Use the double roller set out of my 351 which only has about 2,000 miles on it.
2: buy a new double roller set
3: buy a good gear drive set-up
Any indeas out there on these choices? Obviously using my existing low milage set will save me noney but I am very attracted to the "idea" of a gear drive set and it's inherent added accuracy.
I would love to hear some opinions on gear drives vs chain and whether it would be just plain stupid to put in the old (2,000 miles) set from my 351 or not.
The other item is whether it would be smarter for me to have the cam and roller rockers installed by a pro mechanic (since this is my first build and I'd hate to do something wrong) and since there are several special tools I would have to buy to do it myself that I would only use once and then thats it. So the cost of a pro to come over and help with this part of the build wpuld be offset to some degree by my not having to buy all those special use items.
I do have a lot of reference material/books/articles/DVD on HOW to do it and could probably be OK just by following those methods carefully, but?
Any input on these items would help me make an informed decision.
Thanks, Don

[vector1]

hey don burning the midnight oil?

i would use your old timing set unless there is not enough adjustment to get your cam where you want it then opt for something with more adjustmet. the gear drive thing has kinda went by the wayside.

you should be able to do the cam/timing gear/valve train stuff. get a pushrod length checker and a couple soft springs to replace the valve springs and you can check your piston to valve clearance while you're at it. use some medium strength lock tight on the bolts and use a torque wrench and make sure the threads are clean and dry when you use it.

you should be able to borrow a degree wheel, pushrod length checker, and other assorted stuff from a local cobraite since you're going to use it only once.

take your time and follow the advice in the books and ask lots of questions, you'll be fine.

[donraye]

Originally Posted by vector1

hey don burning the midnight oil?

i would use your old timing set unless there is not enough adjustment to get your cam where you want it then opt for something with more adjustmet. the gear drive thing has kinda went by the wayside.

you should be able to do the cam/timing gear/valve train stuff. get a pushrod length checker and a couple soft springs to replace the valve springs and you can check your piston to valve clearance while you're at it. use some medium strength lock tight on the bolts and use a torque wrench and make sure the threads are clean and dry when you use it.

you should be able to borrow a degree wheel, pushrod length checker, and other assorted stuff from a local cobraite since you're going to use it only once.

take your time and follow the advice in the books and ask lots of questions, you'll be fine.

Wow, I was not aware that I would have to remove any valve springs. I ordered the heads fully CNCed and assembled because I thought that doing the head assembly myself was out of my depth. I thought that removing or especially replacing dual valve springs was difficult without expensive special tools and a lot of knowledge. These springs are way stiff and I know I can buy a spring compressor fairly cheaply to remove them, but what about the replacement of them. Isn't that a lot harder than the removal and take a way more effort, knowledge, and a special tool?
Do I have to remove and then replace them for each cylinder? I was under the impression (perhaps wrongly!) that you could obtain correct push rod length and also install/set the roller rockers with the springs/heads fully assembled as they are. How do I put the springs back in properly, as the little tools I saw for 25-30 bucks to compress them for removal hardly look like they would work in reverse order to install them.
I have the degree wheel, a good torque wrench and adjustable lenth pushrod checker and was planing on getting a dial indicator and megnetic base and pointer for it . Then someone else said they thought I needed "a non hydraulic lifter the same length as my hydraulics to be installed" in order to set up the roller rockers rightly, Anyone know about that idea?
I will have to study this valve train stuff a lot more as it seems in many ways to be the most subtle and challenging aspect of the build.
Does anyone know about the "mid-lift" theory of setting valve/rocker geometry? It's the "only way to do it correctly" according to this racer/designer/engineer guy Jim Miller who nakes some really nice roller rockers I looked at. He says everybody else "has it all whrong and has been wrong for years"! Some of you might want to take a look at his ideas and stuff at www.mid-lift.com and see what you think just for the fun of it. His arguments are pretty compelling about valve train geometry and rocker geometry and set-up.
Oh well! It seems it's like religion and politics. I think I'm feeling a bit over my head at this point. Just shoot me now!
Don

[vector1]

there's different ways to put it together, i just threw out one.

[bobcowan]

A gear drive is more accurate than the gear/chain set up. BUT, only at higher rpm's, and only under a load. They're noisy, wear quickly, and are expensive. If you're building a high rpm drag race only motor, it's a good choice. Stick with what you already have, it's perfect.

It's very important that you check valve to piston clearance during assembly. You don't want to be checking that under power. You don't have to swap in checking springs. It's the easiest way, though.

The "problem" is the hydraulic lifter. Without oil pressure the lifter will collapse and you won't get full lift at the valve. Take the guts out of a hydraulic lifter, and replace the spring assembly with a stack of washers/shims. Then put it all together like final assembly. I set the rocker arms pretty loose to begin with; set it to zero lash and then back off 2-3 turns. That gives me plently of room.

Watch the rocker arm tip as it goes through it's range. That will tell you if your push rod length is OK. Checking push rods are pretty cheap at summit and jegs. They're a very valuable tool.

[donraye]

Originally Posted by bobcowan

A gear drive is more accurate than the gear/chain set up. BUT, only at higher rpm's, and only under a load. They're noisy, wear quickly, and are expensive. If you're building a high rpm drag race only motor, it's a good choice. Stick with what you already have, it's perfect.

It's very important that you check valve to piston clearance during assembly. You don't want to be checking that under power. You don't have to swap in checking springs. It's the easiest way, though.

The "problem" is the hydraulic lifter. Without oil pressure the lifter will collapse and you won't get full lift at the valve. Take the guts out of a hydraulic lifter, and replace the spring assembly with a stack of washers/shims. Then put it all together like final assembly. I set the rocker arms pretty loose to begin with; set it to zero lash and then back off 2-3 turns. That gives me plently of room.

Watch the rocker arm tip as it goes through it's range. That will tell you if your push rod length is OK. Checking push rods are pretty cheap at summit and jegs. They're a very valuable tool.

Thanks for the tips Bob. I gave the heads to my short block builder and he told me that I would have to have a cam lift of over .670 before there would be a clearance issue with the 16cc dish pistons he is using, but I'll double check it anyway to be sure. My cam lift is more in the .540-550 region.
Three more questions for you or anyone out there:
1: The valve spring compressors/removers I can buy reasonably cheaply at Summit look like slender pry bars about 10" long with a hole (I assume for the rocker stud ) a short distance from the flat forked end (which I assume goes around the valve stems to compress the springs). Can I use that same type of tool for putting the springs back in (if I take them out for the light pressure checking ones)?
2: You said you "set to zero lash and then back the adjuster off 2-3 turn to start with". What is the purpose of doing that? Everything I have read so far says to go to zero lash and then tighten the adjuster about 1/2 turn (street engine) to set the proper preload. What is the back off method for?
3: What is the big dis-advantage of simply leaving the real dual springs in the heads to set your rockers and push rods lengths up? I have a crankshaft socket and 1/2" breaker bar to rotate the engine assenbly. Is it that the springs are too beefy to easily rotate the assembly or?

I will for sure have the checking push rods to get the correct push rod length and your tip about the washers/shims in the lifters is a great one. Glad to know that one!

Thanks, Don

[vector1]

you'll want to take one cylinder ex/in spring pair off before you put the heads on, then do all your checking. if you use a pushrod checker with the roller springs installed you'll never get a reading cause the checker with collapse and be unuseable forevermore. i just grabbed 3 or 4 of your lifters and they are not going to collapse, they are still filled with oil so you will not need to take them apart.

the heads do have hyd roller springs and not solid roller springs?

[donraye]

Anyone out there know if I really need to use a degree wheel to check the cam timing or not. I have read a few articles and book segments on building a SBF and none of them so far have used this method. They all simply say to line up the keyways on the crank and cam to the 6:O'clock and 12 O'Clock positions with the #1 piston at TDC and that will set the timing correctly. Is this true or not? They also do not mention anything about using pushrod checkers (?). They just install the atandard length pushrods and then check to make sure that the rollers on the roller rockers are height adjusted to make the path they take over the valve tips in the center of the tip and the arc as equal as possible on both sides of the stud. Then find zero lash and give it 1/2 turn more. Any comments on that mehtod vs. pushrod checkers?
Also: I talked to both the engine builder at Keith Craft and at T&L engines and they both said that the "main girdle" is really only good for "making you feel beter" and it "really does not do much other than that" in their oponion.
Any comments on that observation? I want to do it right but also as simply as possible to get it right.
Don