I need some push rod/rocker arm advice and teaching

[Smokeater11]

OK you engine gurus, I need to pick your brains!! I am making my parts list for my engine build and I am to the point of choosing my upper valve train components. I am going to have a 351W built with pretty much a stock bottom end(except I'm adding forged pistons) and I am planning on using this top end kit from Edelbrockhttp://www.edelbrock.com/automotive_new/mc/power_package/top_end_kits2.shtml part # 2092. It comes with everything but pushrods and lifters. Here lies my question, I want to go with a roller rocker setup but I know nothing about them.
- I don't know what all the ratios mean i.e. 1.6/1.7 etc.
-And someone explain if running a flat tappet cam makes any difference on the rocker arms side of the valvetrain.
-I am assuming that standard length pushrods for a 351W will be correct?
-What brands make the best mid priced components
-Do I need adjustable rocker arms with a non roller cam?
-Can someone give me a proven combination of components that will work with this top end setup.
I can only afford to build this motor once so I need to make sure that I get the right stuff. I am not looking for the absolute most expensive stuff out there but I want to put quality parts in this motor. So any quality educated, experienced advice would be greatly appreciated. Many thanks men!!

Mark

 

[DonsBolt]

I am no expert, but I think it would be more important to buils a motoer witha roller cam and timing chain. Then you can go with any rockers you want, even non roller top rockers.

I am sure the experts will chime in soon

 

[bax]

Those heads will work fine, they are on the small side but you can do better for less dollars. Check out the RHS web site and compare their product. Their cheapest head has a larger intake runner and bigger intake valves than the edelbrock. You can buy the RHS head in cast iron or aluminum. I suggest iron. Also if you are buying new pistons may I suggest an easy lower end mod. It is a low dollar stroker. You use the 351 block with a 302 piston. stock 351 rods and there is a crank for this that is under 300 dollars brand new. the good thing about this stroker is there is no "pushing the limits" like many other strokers. What I am trying to say is save some money on the heads and buy a crank. Just my .02
now for the questions
Roller rocker set up: You say you want to use roller rockers but not a roller cam, Hyd or otherwise. So a roller block or the parts to run a roller cam is not needed. Roller rockers can be used in place of standard rockers without any problems. Some rocker arms require different studs and nuts than others so make sure you get parts that are made to work together. A flat tappet cam makes no difference on the rocker arm side of the valve-train. Quite often stock push-rods will work just fine however I would suggest checking the push-rod length on every build. With a Hyd roller cam or a Hyd cam you do not need adjustable type rockers. For the top end stuff I like comp cams parts. I have never had any problems with their components. Rocker ratios: stock ratios should work just fine if you are not going to run a high lift cam.

I hope this helps some.

 

[Smokeater11]

Thank you Bax, some of the stuff you wrote we talked about the other night but now I have it in writing and can analyze it at my own pace. I'll check out the RHS site and see what I come up with. I do want to use a non roller cam because I don't have a roller block(gotta work with what I got). Where can I find this crankshaft that you are talking about?? on the RHS site?? I take it that by using the 302 pistons and a longer stroke crank that you achieve the desired displacement without boring the block out a lot. And pretty much any rocker will work if you get the proper size for the studs you have(3/8 or 7/16). And no need for adjustable rockers if you run hydraulic lifters, mechanical lifters will require adjustable rockers. Am I on the right track with these statements?

 

[Smokeater11]

What do you think about these? Kinda middle of the road as far as price but seem to compare with the pricer stuff in all the technical areas.
http://store.summitracing.com/partdetail.asp?part=PRO%2D66911&autoview=sku

 

[ricky]

if you want to run a hyd roller cam in your block,you can buy crane "retro fit" lifters,they are hyd and will work fine in your block with the correct length pushrods,that crank he is refering to is made by both Eagle,and Scat to name two..it will make 393 ci with a stock length 351w rod and a .030 302 std height piston..one thing to keep in mind with a stroker of this size is that with additional displacement comes compression ,not sure what size chambers are in the heads you are looking into,but with a flatop piston on this combo,i'd look for something around 66 or so cc to keep it down some..whatever size rocker studs are on your head is what you need to get the roller rockers to match,most are common 3/8 studs,with the larger 7/16 being used by others running alot of lift,etc..i'd go with 1.6 ratio rockers to keep that cam lift in check,make sure you check the piston/valve clearanc..good luck with it!

 

[bax]

if you want to run a hyd roller cam in your block,you can buy crane "retro fit" lifters,they are hyd and will work fine in your block with the correct length pushrods,that crank he is refering to is made by both Eagle,and Scat to name two..it will make 393 ci with a stock length 351w rod and a .030 302 std height piston..one thing to keep in mind with a stroker of this size is that with additional displacement comes compression ,not sure what size chambers are in the heads you are looking into,but with a flatop piston on this combo,i'd look for something around 66 or so cc to keep it down some..whatever size rocker studs are on your head is what you need to get the roller rockers to match,most are common 3/8 studs,with the larger 7/16 being used by others running alot of lift,etc..i'd go with 1.6 ratio rockers to keep that cam lift in check,make sure you check the piston/valve clearanc..good luck with it!

The RHS head has a 66cc chamber,screw in studs and guide plates.

 

[fordguy]

eagle makes the crank you need for the stroker look on this site http://www.eaglerod.com/products/Ford/351/351 cranks.html summit has it for 299.99 i personally would not use forged pistons unless i was going really high compression or juicing it but that is my opinion when i build my 351 stroker (not for the bronco for another project) i will use cast or hyper pistons forged pistons have to have the cylinders a little larger ( actually think they make the pistons smaller) and you can end up burning oil between oil changes from the time it is new RHS has been around a long time they have good products i like the afr 165s but they are high

 

[Smokeater11]

not sure what size chambers are in the heads you are looking into

The Edelbrock heads are 60cc....is that too small? As far as the pistons what is the significance of the 302 piston? Why does it have to be 302 pistons and not stock 351 pistons? Sorry if these questions sound trivial but I'm learning a lot!!

 

[bax]

When I said small I was talking about intake runner cc volume ( 170) and the intake valve size (1.90) 302 pistons wrist pin is in a different location than the 351. this is how the stroke will be made up with the special crank. Advantage is the 302 piston has very safe wrist pin and ring placement. No pushing the limits, lots of good low end #"s and no added durability issues.

 

[Smokeater11]

How about this setup for the bottom end?
http://www.rpmmachine.com/shop/html/351W-to-a-393-Ford-Stroker-Kit-up-to-500HP.html
Scat crankshaft, hyper pistons, and Scat rods and not a bad price either. Which type of piston top should I look getting and what would be a good compression ratio? Again 60cc heads from the kit.

 

[Rustytruck]

Have you looked at the power graphs on those parts from edelbrock? Thats a great street/freeway blasting motor your building but for the money your spending it really sucks for off road. Off road you will never pull those rpm numbers unless you go crazy blasting sand dunes. To run enough fuel to run 6500 rpm and not use it over 3,000 rpm your mileage will really suck. I am just making an observation here as I do not know your intended use.

 

[NYLES]

Have you looked at AFR heads? Or do you like the idea of a complete top end kit? And you can buy Harland sharp roller rockers for under $200. Dont need forged pistons unless your really gonna spray it! HYPER will save you a couple hundred and nobody will ever know the diff.

X2....what RUSTYTRUCK said....Waht are you gonna do with this motor?

You said your going to have it built? Have you talked to your builder? a good one will save you money and get you more motor than you expected.

check out bad-ass racing take note at what parts he puts in his engines will open up your mind and answer some question about what you need....he has some BAD ASS engines in there that will eat crate motors a new one and they are VERY VERY reasonably priced! check out the 325-350HP 351W $3700...or the street beast...$5900...If I were to get a new motor NO dought one of these and pay the core!

http://www.badasscars.com/prices.html

OK! OK! ILL stop.....but you gotta do something with that gator thing...reminds me of my dad.....cant help it Im a NOLE fan!! good luck with your motor...Id like to build one for someone but dont have the time and Im to far away from my machinist...hes good!

I cant help it I like throwing up pics...wish I had time to get all my pics on a computer!

 

[Smokeater11]

To answer your question Rustytruck, this rig will see about 75% on road and it will be backed with the NP435 and 4:11s front and rear so I will have the gear/tranny combo to get the RPMs up when needed off road. I'm not terribly worried about mileage cause it's not my daily driver and I plan to trailer it to the trails when I go. Nyles I will look at the badass site as soon as I post this reply. Thanks
Added: after looking at the power graph again I see what you are talking about in the low RPM ranges as far as HP but it is my understanding that in an off road situation at low rpm that you are looking more for torque than HP anyways. Am I correct with that? You want the motor to pull not boil the tires, right? At 2500 rpm it's making almost 350 ft lbs of torque. Rusty make sure you are looking at the #2092 graph.

 

[broncnaz]

Almost all aftermarket heads are set up for adjustable rockers so any heads with screw in studs will or should be considered adjustable while adjustable is not required for a Hydraulic cam it is a good option. As for rockers I'm using crane energizer roller rockers on my setup they are fairly cheap and I've had zero problems with them they have about 70,000 miles on them. the 1.6 or 1.7 ratio means that it will move the valve 1.6 or 1.7 times the amount that the pushrod moves this gives you more actual lift I'd stay with the 1.6 ratio less leverage = less force on the valve train. As for heads yuou should be fine with a 351 I'm using TFS heads on my 302 and I dont have mileage issues or lowend torque issues while I imagine I could pick up slightly more of both with smaller valves these heads are way better than my old stock ones hands down.
I would wait on ordering pushrods until you have the heads you want to use. Some aftermarket heads use longer than stock pushrods you should measure the required lenght with the heads assembled to your block but you may be able to call the head company and they should know the lenght that usually needed. Also most aftermarket heads will require hardened pushrods as the heads will have guide plates due to the adjustable rocker setup.
Cant think of much else right now I'm sure I missed something. But we can usually answer most questions.

 

[minimatt]

Hey bax, he is looking at the 2.02 valve Edelbrock heads. I would go aluminum heads due the compression you will likely be running. Those particular Edelbrock heads will require adjustable rockers. It always scares me a little to see these kinds of questions on this board. Generally, there needs to be a lengthy dialogue to determine what is the best combination for a particular vehicle, driver and budget.

That being said, the Edelbrock combo comes with lifters and that whole package is a proven combo. If you want to make the same power that they are advertising, call them up and find out what all of the components were, including rocker arms and compression. Block machining will have an impact on the length of (hardened) pushrods required, so you will need to assemble it and verify length before you can order (hardened) pushrods. In most cases the stock length pushrods will work, but it needs to be verified.

Incidentally, I ran a very similar set-up to this in my fastback years ago and it ran 112mph in the quarter. Fun fun fun.