Help: Builing a Street 408

[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

[bobcowan]

1. I find the pry bar type compresser to be difficult to use on the bench. I like the kind that looks like a big C clamp.

2. What you're looking for is piston to valve clearance. I set to vero lash and then back off 2-3 turns. If clearance is going to be a problem, you'll be able to see it then, before the valves actually contact the pistons. Even if turning by hand, you can damage a valve if the clearance isn't there.

3. The issue is with the hydraulic lifters. They're designed to collapse a little bit under use. When there's no oil pressure, they will collapse a lot more, and you'll never get full valve lift.

[donraye]

Originally Posted by bobcowan

1. I find the pry bar type compresser to be difficult to use on the bench. I like the kind that looks like a big C clamp.

2. What you're looking for is piston to valve clearance. I set to vero lash and then back off 2-3 turns. If clearance is going to be a problem, you'll be able to see it then, before the valves actually contact the pistons. Even if turning by hand, you can damage a valve if the clearance isn't there.

3. The issue is with the hydraulic lifters. They're designed to collapse a little bit under use. When there's no oil pressure, they will collapse a lot more, and you'll never get full valve lift.

Thanks Bob, That's helpful to know.
The lifters I'm using are actually from another engine and are still full of oil so they will not colapse. Is that going to be a problem since as they are "pumped up" and will not collapse at all probably? Will that make adjusting the valve lash or rockers a problem using them on the cam and roller rocker install?
I think I read in my cam installation directions from Comp Cam that it was "not desirable" to use lifters filled with oil for the cam installation. Anyone know about that? I would really like to know before I use them if that is going to be a problem or not.
Don

[bobcowan]

Originally Posted by donraye

Thanks Bob, That's helpful to know.
The lifters I'm using are actually from another engine and are still full of oil so they will not colapse. Is that going to be a problem since as they are "pumped up" and will not collapse at all probably? Will that make adjusting the valve lash or rockers a problem using them on the cam and roller rocker install?
I think I read in my cam installation directions from Comp Cam that it was "not desirable" to use lifters filled with oil for the cam installation. Anyone know about that? I would really like to know before I use them if that is going to be a problem or not.
Don

Yes, they will collapse. Just watch the plunger when you rotate the engine. Even when filled with oil and the engine running, they will collapse a little bit. That's the design of a hydraulic lifter.

I don't install my lifters with oil in them. I coat the bodies with assembly lube, and put a littl on the rollers. Before engine start I spin the oil pump with a drill motor until oil comes up to the rocker arms. That tells me the lifters are now full.

[J Persons]

If you have an extra hydraulic lifter, disassemble it, clean it in carb cleaner and fill it with epoxy, then re assemble. It will act as a solid lifter for checking purposes. No worries about the lifter collapsing under spring pressure or anything. Just be sure and don't install it in the engine during final assembly.

If you have stud mounted rockers and hydraulic lifters, you can gain 200 to 300 more RPM if you adjust the lash so that it's at 0, then lock it down. This will put the lifter plunger at the top of its travel, and will prevent lifter pump up at high RPM. Adjust the valves at operating temp. Trade off is they can sometimes be noisy.

[donraye]

Hi all, I have just about every big and little thing for the 408 build now and have just pulled the 351 out of the car, so I will be starting the buld soon.
I will be robbing a lot of periferals from the 351 but some things will not transfer like the flywheel and the balancer which are both 28.8 oz. external balance and I will need neutral balance since the 408 is internally balanced.
But the question I now have for anyone is:
I have a perfectly functioning 10.4" OEM type clutch and pressure plate set-up with only 1,700 miles on it. I need to know if it will stand up to the 500+ crank HP of the 408 or not.
It will not be raced but of course there will be the glorious at least occasional "lead foot" (as one reason I have a Cobra to begin with!).
Will I need to just forget about the OEM clutch and get a Centerforce (or some other) that has about 90% more holding force than the stock unit? Or can I get by reasonably well with stock?
I hate to spend the extra dough at this point but would would hate to be replacing the clutch soon to put one in then even more!
One reason i hate to go to a new clutch pressure plate, etc. is that I think it will make the intall harder since the bellhousing/tranny are still in the car and the onld broken in clutch would mate up a lot easier than a new one when I put the new engine back in. I would that make that much difference? Was hoping to not have to disturb the stuff still in the frame/car.
Don

[bobcowan]

>> I have a perfectly functioning 10.4" OEM type clutch and pressure plate set-up with only 1,700 miles on it. I need to know if it will stand up to the 500+ crank HP of the 408 or not. <<

I doubt it. Because the car is so light, and you're not running slicks, you really don't need a racing clutch. But the stock one won't last.

My engine puts 470hp to the pavement. I have run it down the 1/4 miles a few times, with slicks. I run it on the road course fairly often, and I'm not afraid to beat on it on the street (no racing).

My clutch is a Centerforce dual friction. After two years of abuse, it looks surprisingly good. I'm installing another one just like it.

[donraye]

Originally Posted by bobcowan

>> I have a perfectly functioning 10.4" OEM type clutch and pressure plate set-up with only 1,700 miles on it. I need to know if it will stand up to the 500+ crank HP of the 408 or not. <<

I doubt it. Because the car is so light, and you're not running slicks, you really don't need a racing clutch. But the stock one won't last.

My engine puts 470hp to the pavement. I have run it down the 1/4 miles a few times, with slicks. I run it on the road course fairly often, and I'm not afraid to beat on it on the street (no racing).

My clutch is a Centerforce dual friction. After two years of abuse, it looks surprisingly good. I'm installing another one just like it.

I suppose I can not simply use a new clutch dics from Centerline with my OEM pressure plate. Will I need the whole set-up from them or would one of their disc work with the existing pressure plate? (I am dreaming I suppose to think I could get away with that at just $90!).
D.

[bobcowan]

Originally Posted by donraye

I suppose I can not simply use a new clutch dics from Centerline with my OEM pressure plate. Will I need the whole set-up from them or would one of their disc work with the existing pressure plate? (I am dreaming I suppose to think I could get away with that at just $90!).
D.

I'm sure you could. I don't see why you couldn't use a Centerforce disc with a stock pressure plate. I don't know how long it will last, but it would work.


The Centerforce PP is made by Valero - they make a lot of clutch parts for aftermarket companies. But Centerforce adds the weights to increase clamping force as the rpm's climb; that's the real "magic".

[donraye]

Originally Posted by bobcowan

I'm sure you could. I don't see why you couldn't use a Centerforce disc with a stock pressure plate. I don't know how long it will last, but it would work.

The Centerforce PP is made by Valero - they make a lot of clutch parts for aftermarket companies. But Centerforce adds the weights to increase clamping force as the rpm's climb; that's the real "magic".

Want to buy a new Centerforce complete clutch kit for the 408. Problem is I do not know exactly what to buy for sure. As near as I can figure the clutch I have is a Sachs OEM replacement of some sort but there are no mumbers on it that make any sense with what I can find online in parts sources.
I know the disc says Sachs and is a 10.5" disc. the pressure plate is a 10.5" God knows what and the main number on it it is a huge cast in "MF265". When I try to search it online all I come up with is a Massey Furgerson Tractor part! Know that isn't right but damned if I know what it is? It does say Made in Mexico on the perimeter of it but that is no real help. It seems to me it is NOT the correct OEM clutch for the block I have/had, but if worked fine! So I am trying to find a direct replacemnt for it in a much more robust form like the "Centerforce Dual Force" line.
So... I think (?) I can use the Centerforce model # DF021057 See it at:
( http://store.summitracing.com/partde...5&autoview=sku ) Which is actually supposed to be for a 1995 5.8 liter/351 Windsor Mustang Cobra "R". It is the only one I can find for a 351 Windsor that is 10.5" (like the one I have now is) and will work with my new billit steel SFI flywheel which will only take a 10'5" MAX clutch size (not an 11" like most of the 351 clutches I see out there). And I think it will be compatible with my T5 Z spec.
Are there any reasons anyone can think of that this model clutch will not work for me even though it is probably not OEM for this engine block butit is the same disc size, shaft size, 10 spline, for 351 windsor, etc. The photo of it looks right and the bolt hole placements, etc seem right in the photos, but I'm no clutch expert.
All the other 351 windsor clutches I can find are either 11" (won't work with my flywheel), or the 10" ones that are all for 289/302. So this seem to be the correct one for my application being it is for a 351W and is a 10 spline with the correct size input shaft, etc.
Any more educated thoughts out there?
If not, I think I will buy it from Summit because if it turns out it is wrong they make it pretty easy to return. If I get it and carefully compare it to the unit I am replacing and all seems the same: outer dimensions, holes line up, same overall thickness of the assembly, splines fit right, etc. then it will be good to go. Right?
D.

[392cobra]

Originally Posted by bobcowan

The Centerforce PP is made by Valero - they make a lot of clutch parts for aftermarket companies. But Centerforce adds the weights to increase clamping force as the rpm's climb; that's the real "magic".

I have the Centerforce clutch behind a BBC in a '67 RS/SS.
It does clamp,just like I want and need.

The down side is it is SLOW to release at rpm's above 6k.If you're looking to shift fast,get rid of the weights they add to them.

[donraye]

Originally Posted by 392cobra

I have the Centerforce clutch behind a BBC in a '67 RS/SS.
It does clamp,just like I want and need.

The down side is it is SLOW to release at rpm's above 6k.If you're looking to shift fast,get rid of the weights they add to them.

My understanding from research and talking to other Centerforce users is that the weights are the reason the Centerforce is able to provide 90% more clamping power than OEM type units. If you remove them then I think you might as well just use one of their disc with your OEM type pressure plate and save the $ spent on their "weighted pressure plate technology".
Also: I'm running a hyd. roller cam and I doubt that I will ever fell the need shift fastly above the 6,000 RPM level, as my cam is pretty much "done" it's best by 6,000 RPM anyway. I have no desire to "speed shift" at all much less at or above 6,000. There are no racing intentions just a strong pulling street performance engine with no powershifting/speedshifting desires.
Thanks for the good input but I think for my needs the clutch will shift as quickly as I will ask it to on all but perhaps the rarest of occasions.
I do however truly appreciate your reply and your giving me some much needed education on the subject.
Thanks, Don
P.S. That Lone Star looks great and my favorite color (next to the more unique "Grabber Orange" anyway). I really like their LS427 Cobras and think they are among the very best out there. A lot of folks don't know about them but they should. Comfortable too, plus they make a really nice and afordable removable hard top for them as an option. My next one (if there is a next one) might be a Lone Star kit. They have a great 7 day home build program also. You made a great choice!
Really like them.

[392cobra]

I didn't know that about the Centerforce when I installed it behind a 550 hp 454".I just knew about it's great ability to clamp.
If I were to race the Camaro,it woud be a major draw back,but I don't.

Knowing it when I put the second engine an clutch in my Cobra I did not go that way.I shift at 6.8k with the Keith Craft 418".
I run Mcleod twin disc and really like it A LOT.

Sounds like you are making great progress ! Been following your work.

[donraye]

Hi Everyone, The 408 (which has now become a 418) build is almost completed and all has gone pretty well so far.
I'm now at the point where I need to stab the distributor and do the engine intall, and I'm confused about how to do the distributor stab correctly for setting the initial timing.
I will be using the same MSD that was on the 351W with this 418. The only thing I changed on it was to buy a phenolic gear for it so I can use it with the steel core Hyd. Roller cam I have in this 418.
I intend to take the car to have it dyno tuned as soon as I have it back together and a few break-in minutes/miles on it. So I'm just wanting to get the engine set up so I will not hurt it until drive it have it professionally tuned.
My question is about stabbing the MSD distributor. I do not have a timing light and hoped not to have to get one as it will be going to the engine builder's dyno for tuning ASAP. So... Can I simply install the MSD by stabbing it with the timing mark on my balancer set on 10-12 degrees advance of TDC?
Or do I need to install it with the mark on the ballancer at 0 degrees TDC?
Someone said to use the 0 degree mark then "turn the distributor base" to advance the timing, but without a light this seems very iffy, if correct at all. Why not install the distributor with the timing mark at about 12 degrees (or if someone has a better starting set point?).
I will not fool with the internals of the distributor as it was fine in the 351 and I would not know what I was doing in there anyway.
The static compression in this engine is 10.3 to 1 the cam is a Comp Cams custom grind for the street from Keith Kraft. with:
Duration at .006 is 287 and 293
Timing @ .050 of: intake: 14 BTDC and 42 ABDC
exhaust: 53 BBDC and 9 ATDC
Separation is 108
Lobe lift is .347 and .360
Gross lift is: .555 and .576
All I want to do here is get the engine running without screwing somethig up or destroying it until I get it to the dyno about a half hour drive away.
Any help or better yet detailed step by step instructions for installing the distributor.
I know about how to set up the plug wires, etc. It's the degree to intall or stab it that's a mystery. And IF it is stabbed at 0 degrees on the balancer how do I set the initial advance without a timing light. Or can I?
HELP!

[bobcowan]

I mark the rim of the distributer for the #1 position. I set the balancer at the 10* mark. Then install the distributer with the rotor pointing to the mark. That gets it pretty close.

A basic timing light is pretty cheap; around $40. Spend the bux and get one.

[donraye]

Originally Posted by bobcowan

I mark the rim of the distributer for the #1 position. I set the balancer at the 10* mark. Then install the distributer with the rotor pointing to the mark. That gets it pretty close.

A basic timing light is pretty cheap; around $40. Spend the bux and get one.

Thanks Bob! I'll spend the bux for the light but I needed the other advice as well as it confirms what I was thinking about using the marks.
Can't wait to get this new 418 in the car and be driving it again. Yahoo!
D.

[Paul F]

Don, what are the final results on your build?

Did you achieve your goals?

[donraye]

Originally Posted by Paul F

Don, what are the final results on your build?

Did you achieve your goals?

Yes, the build was a success and the goal was achieved. Although the HP was a little bit lower than expected it is certainly enough for a street car at just above 510. The torque came in at around 520. These are dyno. proven results and and not fantasy numbers. I could achieve more HP by changing the carb from the 770cfm Street Avenger to an 750 or 800cfm double pumper or Demon, and more yet if I went to a Victor or even Victor Jr. intake. With those changes it should easily be in the 550+HP range, but I like the low end power of the Performer RPM Air Gap and am willing to sacrafice the higher RPM gains of the Victors for that, as that's where I usually use/want the power for the street.
I have gained about 225HP from what I had with the old 351 in the car and it has completely changed the personality of the Cobra from mild to wild.
I do miss some of the streetability of the old mild engine as this one does not do "slow" as well. But it's a trade off I am fine with and this engine is still quite at home in most situations and traffic. No problems with cooling at all but the cam makes the car a wee bit lumpy below 2000-2500 RPM and the sweet spot is up around 3000 to 4000 so gear selection is a slighly larger issue than with the old 285HP 351 in that way.
The 351 produced very smooth power at almnost any RPM but there was also a total lack of drama and aggressive potential as well. This 418 is an "animal" and requires a bit more thought to drive as pleasantly but the reward is the power potential it has for excitement when called on to produce it.
It's now your turn to build yours soon and we'll see if you can do even better with your build.
The biggest gain for me is in the satisfaction of doing this myself with no previous experience at it, and knowing every part in it "personally". Building this car and especially this engine is a dream I have had since age 16 when I saw my first 427 Cobra close up. Now I've finally (at age 63) done it. Far better late than never!
Nothing you simply "buy" can give that same sort feeling of accomplishment and pride in my opinion. (not that there's anything wrong in buying an engine/car, but it's just not the same as when you actually build them yourself)
None of this could have been done without the incredible advice and support from the people here on these forums and other Cobra owners and builders here at ClubCobra.com who were always more than generous in providing the answers I needed and expertise I lacked whenever I asked.
D.