'71 429 cobra jet engine - correct cam shaft to use today...

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'71 429 cobra jet engine - correct cam shaft to use today...

Post  Pastel Blue on July 13th 2016, 9:43 am

I am getting ready to send my engine in to the machine shop, would like to address the camshaft requirements before I drop the engine off. I am looking to rebuild the engine fairly close to stock including the new camshaft and valve train components. I am not sure if should look at going to a roller valve train or stay stock? The car will be mainly used for a few cruises and some shows, that's it. I am thinking a 10-1 compression ratio will allow me to run on pump gas in my area? Not sure if other specs are needed, but just in case: 715cfm Rochester quadrajet carb (factory on the '71 429cj engine), C-6 auto with the factory stall convertor, 3.25 trac-lok factory gears, 14"X7" factory tires. The engine is at a current .40" overbore, hoping it wont have to be bored further... haven't figured out what pistons would be best at this stage.

The original cj cam specs. .282 degrees intake, .296 degrees exhaust, .506" lift intake & exhaust.

Is there a good cam and valve train kit out there that would operate close to these parameters that I should look at?

It would be nice if I had some information to bring to the rebuild shop so they have an idea on what I am trying to achieve.

Appreciate any thoughts for this factory re-build. Thanks

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  crittersf1 on July 13th 2016, 9:50 am

Weight of car, gearing, tire size?
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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  rmcomprandy on July 13th 2016, 9:51 am

Pastel Blue wrote:I am getting ready to send my engine in to the machine shop, would like to address the camshaft requirements before I drop the engine off. I am looking to rebuild the engine fairly close to stock including the new camshaft and valve train components. I am not sure if should look at going to a roller valve train or stay stock? The car will be mainly used for a few cruises and some shows, that's it. I am thinking a 10-1 compression ratio will allow me to run on pump gas in my area? Not sure if other specs are needed, but just in case: 715cfm Rochester quadrajet carb (factory on the '71 429cj engine), C-6 auto with the factory stall convertor, 3.25 trac-lok factory gears, 14"X7" factory tires. The engine is at a current .40" overbore, hoping it wont have to be bored further... haven't figured out what pistons would be best at this stage.

The original cj cam specs. .282 degrees intake, .296 degrees exhaust, .506" lift intake & exhaust.

Is there a good cam and valve train kit out there that would operate close to these parameters that I should look at?

It would be nice if I had some information to bring to the rebuild shop so they have an idea on what I am trying to achieve.


Use the marine camshaft, (it is really close), which is available from a lot of places; it used to be available from Ford Racing as M-6250-A460 but, not anymore.


Last edited by rmcomprandy on July 13th 2016, 9:54 am; edited 1 time in total

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  crittersf1 on July 13th 2016, 9:53 am

I'm an idiot
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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Straubtech on July 13th 2016, 10:14 am

Pastel Blue wrote:I am getting ready to send my engine in to the machine shop, would like to address the camshaft requirements before I drop the engine off. I am looking to rebuild the engine fairly close to stock including the new camshaft and valve train components. I am not sure if should look at going to a roller valve train or stay stock? The car will be mainly used for a few cruises and some shows, that's it. I am thinking a 10-1 compression ratio will allow me to run on pump gas in my area? Not sure if other specs are needed, but just in case: 715cfm Rochester quadrajet carb (factory on the '71 429cj engine), C-6 auto with the factory stall convertor, 3.25 trac-lok factory gears, 14"X7" factory tires. The engine is at a current .40" overbore, hoping it wont have to be bored further... haven't figured out what pistons would be best at this stage.

The original cj cam specs. .282 degrees intake, .296 degrees exhaust, .506" lift intake & exhaust.

Is there a good cam and valve train kit out there that would operate close to these parameters that I should look at?

It would be nice if I had some information to bring to the rebuild shop so they have an idea on what I am trying to achieve.

Appreciate any thoughts for this factory re-build. Thanks

I would suggest going roller. No break in time, power power under the curve.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Super Snake Steve on July 13th 2016, 11:50 pm

If money is an issue I would go with a solid lifter cam unless you don't like how they sound for me the sound of a solid lifter cam is like music to the ear love'em like Chris said roller equals power power j

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'71 429 cobra jet engine rebuild...

Post  Pastel Blue on July 14th 2016, 7:00 am

Super Snake Steve wrote:If money is an issue I would go with a solid lifter cam unless you don't like how they sound for me the sound of a solid lifter cam is like music to the ear love'em like Chris said roller equals power power j

I would certainly have gone the solid lifter route if the engine (car) was a true scj version from the factory, not in this case. I am going to talk to my machine shop about installing the roller set up. Cant think of any drawbacks off the top of my head, unless someone here has something?

Ill have to look into where I can get the marine version of the cj camshaft, being in Canada, I am pretty sure I will have to order the set up out of the states.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Super Snake Steve on July 14th 2016, 8:16 am

This would be a good time for the professional engine guys to clear this up as far as the roller set up's go's I've read a few times on this board that a roller set up in the 385 series that a roller up is a lot of maintenance and for a street set up it is normally recommended to go solid and sometimes hydraulic can't remember just how its go's but its recommended to use either hydraulic lifters with solid roller or solid lifters with hydraulic roller like I said can't remember witch way I don't know why you wouldn't use say solid roller cam with solid roller lifters with that said I stopped by Jon Kaase shop about a year ago and I asked him about running roller set up on the street and maintenance and he said not a problem anymore and he had that all worked out and a roller for the street was reliable of course he didn't go into detail of what all he has done to achieve this so anyone wanting to share please do thanks

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Scott Foxwell on July 14th 2016, 8:42 am

With today's hyd. roller lifters IMO there's no need to go solid unless you want to, or are building 100% race engine. I personally just won't risk flat tappet anything any more.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  supervel45 on July 14th 2016, 9:06 am

Has anyone tried Ion Bond DLC yet on a cam or lifters. From what I've seen, and I have worked with it a little, it's some very nice stuff, very hard, and pretty slippery, and might be the ticket on HFT an Solids, to cut down on the problems?

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  rmcomprandy on July 14th 2016, 9:13 am

Super Snake Steve wrote:This would be a good time for the  professional engine guys to clear this up as far as the roller set up's go's I've read a few times on this board that a roller set up in the 385 series that a roller up is a lot of  maintenance and for a street set up it is normally recommended to go solid and sometimes  hydraulic can't remember just how its go's but its recommended to use either hydraulic lifters with solid roller or solid lifters with hydraulic roller like I said can't remember witch way I don't know why you wouldn't use say solid roller cam with solid roller lifters with that said I stopped by Jon Kaase shop about a year ago and I asked him about running roller set up on the street and maintenance and he said not a problem anymore and he had that all worked out and a roller for the street was  reliable  of course he didn't go into  detail of what all he has done to  achieve this so anyone wanting to share please do thanks

As long as there are SHAFT type rocker arms or BOLT DOWN type rocker arms used, which do not twist from side to side, it can work OK.
There WILL be rapid wear on the valve guides or valve stems of a high usage engine when stud / guideplate rocker geometry is used with that extra pushrod side angle.
ANY rail guided rocker type set-up is just asking for trouble.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  rmcomprandy on July 14th 2016, 9:17 am

supervel45 wrote:Has anyone tried Ion Bond DLC yet on a cam or lifters. From what I've seen, and I have worked with it a little, it's some very nice stuff, very hard, and pretty slippery, and might be the ticket on HFT an Solids, to cut down on the problems?

There are NO PROBLEMS at all when high performance OEM type valve spring pressures are used.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Scott Foxwell on July 14th 2016, 9:18 am

supervel45 wrote:Has anyone tried Ion Bond DLC yet on a cam or lifters. From what I've seen, and I have worked with it a little, it's some very nice stuff, very hard, and pretty slippery, and might be the ticket on HFT an Solids, to cut down on the problems?
By the time you pay for that you might as well just do a hyd. roller. As good as flat tappets can be, you'll never equal the power form a roller, even in mild performance. What I mean to say is, I know...500 hp is 500 hp, roller or not, but you'll do it so much more efficiently and with a lot more peace of mind with a roller. JMO.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Scott Foxwell on July 14th 2016, 9:21 am

rmcomprandy wrote:
Super Snake Steve wrote:This would be a good time for the  professional engine guys to clear this up as far as the roller set up's go's I've read a few times on this board that a roller set up in the 385 series that a roller up is a lot of  maintenance and for a street set up it is normally recommended to go solid and sometimes  hydraulic can't remember just how its go's but its recommended to use either hydraulic lifters with solid roller or solid lifters with hydraulic roller like I said can't remember witch way I don't know why you wouldn't use say solid roller cam with solid roller lifters with that said I stopped by Jon Kaase shop about a year ago and I asked him about running roller set up on the street and maintenance and he said not a problem anymore and he had that all worked out and a roller for the street was  reliable  of course he didn't go into  detail of what all he has done to  achieve this so anyone wanting to share please do thanks


There WILL be rapid wear on the valve guides or valve stems of a high usage engine when stud / guideplate rocker geometry is used with that extra pushrod side angle.
Why is that?

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'71 429 cobra jet engine rebuild...

Post  Pastel Blue on July 14th 2016, 10:21 am

Scott Foxwell wrote:
rmcomprandy wrote:
Super Snake Steve wrote:This would be a good time for the  professional engine guys to clear this up as far as the roller set up's go's I've read a few times on this board that a roller set up in the 385 series that a roller up is a lot of  maintenance and for a street set up it is normally recommended to go solid and sometimes  hydraulic can't remember just how its go's but its recommended to use either hydraulic lifters with solid roller or solid lifters with hydraulic roller like I said can't remember witch way I don't know why you wouldn't use say solid roller cam with solid roller lifters with that said I stopped by Jon Kaase shop about a year ago and I asked him about running roller set up on the street and maintenance and he said not a problem anymore and he had that all worked out and a roller for the street was  reliable  of course he didn't go into  detail of what all he has done to  achieve this so anyone wanting to share please do thanks


There WILL be rapid wear on the valve guides or valve stems of a high usage engine when stud / guideplate rocker geometry is used with that extra pushrod side angle.
Why is that?

OK... a good read, all of these responses, but I am no closer to addressing the initial question of remaining with the factory rocker set up or upgrading to roller for my engine build. is there a conclusion that most here would agree with, considering what I am building the engine for? thanks

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Super Snake Steve on July 14th 2016, 10:30 am

Yes you should be closer with that info you said you were considering a roller cam well now you know you have to use shaft or bolt down type rocker to keep from side to side wear and you want to use stock type stuff so you need to go with FTH cam and as far as specs and finding what you want any engine builder here can grind what you need for about the same cost of you tracking down a CJ or marine Spec cam

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Scott Foxwell on July 14th 2016, 12:10 pm

Super Snake Steve wrote:Yes you should be closer with that info you said you were  considering  a roller cam well now you know you have to use shaft or bolt down type rocker to keep from side to side wear and you want to use stock type stuff so you need to go with FTH cam and as far as specs and finding what you want any engine builder here can grind what you need for about the same cost of you tracking down a CJ or  marine  Spec cam
I'm going to disagree with that but I'm waiting for Randy to answer my question. Might be something I don't quite understand about the 385 valve train. I've worked with lots of canted valve heads and never had a reliability or longevity issue with studs and guide plates and aftermarket rockers as long as geometry is right.

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Lunati Claimed CJ Cam

Post  supervel45 on July 14th 2016, 12:14 pm


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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Super Snake Steve on July 14th 2016, 12:34 pm

I'm sure he will give the right answer better than mine but I thing the 385 series cam sits up high in the block and makes it hard on the rollers that why some bore lifter bores the use bigger dis roller is that close Randy

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  SLord82 on July 14th 2016, 12:50 pm

I believe what Randy is talking about with side loading is Hydro Roller specific. Hydro rollers are taller than flat tappet or solid rollers which cause pushrod angle issues not found with flat tappets or solid rollers. The work around is to use a shaft rocker that will stay in place and not deflect due to the weird valvetrain geometry.

To the OP and his original question; use the HFT Randy mentioned if you want it close to stock.

If you want more power use a custom cam that matches your needs and goals. There is nothing wrong with a flat tappet though. There was a build posted a few months ago (I think most here have seen it) that made around 700hp on pump gas with SCJ heads and a moderate SFT.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Scott Foxwell on July 14th 2016, 1:02 pm

SLord82 wrote:I believe what Randy is talking about with side loading is Hydro Roller specific. Hydro rollers are taller than flat tappet or solid rollers which cause pushrod angle issues not found with flat tappets or solid rollers.

Agree but it's the same with all hyd. rollers in any canted valve engine. They usually shorten up the pushrods by about .800". I'm hoping to learn what's different about the 385 series.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Pastel Blue on July 14th 2016, 3:27 pm

This could all be a moot point (for my application ) as I should have added that because I am doing a stock restoration on the car, I will be using the original aluminum cj valve covers. Not sure if this has any bearing on running roller rockers... The factory covers have the drip rails... Thoughts?

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  billandlori on July 14th 2016, 6:23 pm

Pastel Blue wrote:This could all be a moot point (for my application ) as I should have added that because I am doing a stock restoration on the car, I will be using the original aluminum cj valve covers. Not sure if this has any bearing on running roller rockers... The factory covers have the drip rails... Thoughts?

I am running Harland Sharp roller rockers with the stamped steel Edelbrock valve covers, they are the same as stockers and they clear. Not sure about the drip rails. I live in Stratford, about an hour or so away from you. You can try them on my engine if you want!!

Bill
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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  Lem Evans on July 14th 2016, 7:35 pm

" I am looking to rebuild the engine fairly close to stock including the new camshaft and valve train components. The car will be mainly used for a few cruises and some shows, that's it. I am thinking a 10-1 compression ratio will allow me to run on pump gas in my area?"

It sounds like you are looking to do a fresh classic engine that's just a little bit better than stock. If so, a hyd. flat tappet deal would do the job. If a guy was paranoid about a flat tappet deal he could have the cam nitrided. Given your stated use, I don't see where there would be enough spring load involved to worry about.

It's a simple deal I.M.O. but, sometimes solutions are looking for a problem.

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Re: '71 429 cobra jet engine - correct cam shaft to use today...

Post  FalconEh on July 14th 2016, 8:27 pm

Pastel Blue wrote:This could all be a moot point (for my application ) as I should have added that because I am doing a stock restoration on the car, I will be using the original aluminum cj valve covers. Not sure if this has any bearing on running roller rockers... The factory covers have the drip rails... Thoughts?

Lem Evans wrote:" I am looking to rebuild the engine fairly close to stock including the new camshaft and valve train components.  The car will be mainly used for a few cruises and some shows, that's it. I am thinking a 10-1 compression ratio will allow me to run on pump gas in my area?"

It sounds like you are looking to do a fresh classic engine that's just a little bit better than stock. If so, a hyd. flat tappet deal would do the job. If a guy was paranoid about a flat tappet deal he could have the cam nitrided. Given your stated use, I don't see where there would be enough spring load involved to worry about.

It's a simple deal I.M.O. but, sometimes solutions are looking for a problem.  
 

^^^^^^^^^This^^^^^^^^^^^^^

   I agree with Lem, as a resto deal you will have minimal maintenance, cost, and I think you want it stock-ish sounding, you can still do the roller rockers I believe the drip rails are removeable if they interfere, my Boss Cleveland ones needed a 3/4" hole drilled in each of the filler pans (which are wider than 385 series) to clear roller rockers it is a healthy SFT but the valve covers seem like they are off more than they are on.
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