351 C Heads need advice

[rentascout]

Okay so the motor is back together and I have read so many different things about the heads and making sure they don't burn threw another cam, because I failed to do it right. I have no idea if the cam will alter my push rod or if I can still run the std rods.

I have all the pictures in the rebuilding the 351C but I had to send the last set of rods back because they were for a M, go figure. I had the entire head gone back through from values to springs, and I have the non adjustable rockers but I need help on what I should be looking for and how to do it.

Rocker arm clearance and what is lifter reload, I heard I button everything down with 20Ft and crank engine over twice and mark where it traveled then losen and do the same then check the difference and it should be around .20-.40 but again I jacked this last motor up so over thinking everything.

I was also told I could use the factory gear and have no issues. I still have the old rods that I would like to put in there and check clearance but I need a head guy to break this down for me please.

Valve lash should not apply to me correct

Cam specs are also in the rebuilding post so you can see what I have got going. Please help me

 

[Don C]

There are always a few issues with reusing parts, especially those that move. Parts that move against other parts can develop wear patterns that can increase the wear if not reused against the same part. This is why most moving engine parts are labeled and reinstalled in their original position.

If you want to reuse the push rods they will need to be thoroughly inspected. Inspect the ends to make sure they are bright and smooth, no galling. Check them for straightness, this is done by rolling them across a pane of glass to make sure there isn't any wobble. Make sure the hole through them isn't plugged.

Lifter preload is the amount of pressure on the hydraulic lifter when the valve is closed.

The cam manufacturer should be able to give you their recommended push rod length, which you can compare against the stock length.

Many people break in the cam with break-in springs (weaker), or if using double springs with the inner spring removed. This doesn't put as much pressure and wear on the new cam and lifters.

 

[jorgem2]

You should adjust/check your rocker arm adjustment even if they are non adjustable, since the engine has been apart and surfaces machined, clearances changed etc.

Here is how

http://www.cranecams.com/pdf-tech-tips/hydro-lift.pdf

Also make sure that pushrods are not bent and lifters rotate easily in their bores. Lifters have to rotate as they move up and down to prevent cam lobe from wearing away

 

[will e]

There used to be shims available via SVO, I ended up using some on my rebuild. I forget how I knew I needed them, I think it was the Rhodes lifter instructions on how to check/set lash but I don't have the instructions anymore.

 

[jorgem2]

Here are the shims needed

http://www.summitracing.com/parts/crn-99170-1/overview/

 

[rentascout]

Well I bought the cam kit which came with lifters and rods, when I took the engine in I had them order the comp valves and springs to match. I am just waiting on this guy to get off his butt and send them to me. He already sent it to the wrong address so who knows how long it will take. The ones we call old only have a few hours of moving but I got brand new ones. I assume that those rods should help match everything else.

I know they talk about removing the inner spring but I don't have the tools to reset the springs, I know if I run it at the correct rpm and time I help to increase the life of it and greatly reduce burning through another.

Also if the preload is off is that the length of my rod or what. Everything is brand new guys I am not risking a 30 dollar bill over the 1300 I just paid to get it back up. I really need to find the correct way. If there are any videos please let me know, cannot afford another oh man moment.

 

[Don C]

The preload on nonadjustable rockers is either by push rod length or shims between the rocker and pedestal. I believe that standard push rod length variations are plus or minus 0.060 inch.

 

[kidwithfastback=fast]

With all honesty, if you have the money id get roller rockers. They work with standard pushrods fine. Thats what I have.

 

[rentascout]

Everybody and that roller rocker system they assume if you spend more money it will give you more gain, come on I just need to numbers and steps not someone telling me to spend another 1000 for no gain yes no gain unless you are striping it are you really going to see a difference. I have some ocean front property in Kansas if you would like, Real cheap

 

[jorgem2]

Here are the instructions on how to set the valves/rockers with shims. Should have sent this link first. Even with new parts the old block, head, valve seats have dimensions that have changed once they have been machined or rebuilt

Shims are cheaper than custom size pushrods.

http://www.cranecams.com/uploads/instructions/151g_.pdf


Here are the instructions on how to set the valves/rockers with shims. Should have sent this link first. Even with new parts the old block, head, valve seats have dimensions that have changed once they have been machined or rebuilt

Shims are cheaper than custom size pushrods.

http://www.cranecams.com/uploads/instructions/151g_.pdf

 

[mustang7173]

rentascout,

Do you have the cam kit number? You did the right thing by purchasing the cam, rollers, valves, and springs as a matched set. That does take a lot of guess work out of trying get everything right. What does the instruction state?

http://www.enginelabs.com/engine-tech/engine-tech-flat-tappet-lifters-still-viable-in-performance-engines/

Excerpt: Friction reduction and profile shaping are the roller tappet’s distinct advantages over flat tappets. Rolling contact surfaces enjoy a lower coefficient of friction than sliding surfaces; which is an important factor in a factory production engine that needs to balance power, fuel economy and durability. But the overall friction reduction is not as great as expected, because the similar-style lifter bodies generate the same drag within their individual bores.

So, flat tappet type lifters are still a valid system today.

Checkout this Y-Tube-I believe this is what you are looking for!


Let us Know!

mustang7173

 

[turtle5353]

If you are worried about the pushrod length, then I would take it to the machine shop that did your motor and ask them to measure to see what length pushrods you need. They can put a pushrod tool in there and check to verify you have the correct length pushrod or tell you what length you need. And since your cam is not that big I wouldn't worry about running with the lighter break-in springs. Have them set the valves and then bring it home and fire it up. Once you have the correct length I believe that its just a torque setting for the nuts with the oem style like you have. That's what I would do to take all the guess work out of it for you.

 

[rentascout]

If you are worried about the pushrod length, then I would take it to the machine shop that did your motor and ask them to measure to see what length pushrods you need. They can put a pushrod tool in there and check to verify you have the correct length pushrod or tell you what length you need. And since your cam is not that big I wouldn't worry about running with the lighter break-in springs. Have them set the valves and then bring it home and fire it up. Once you have the correct length I believe that its just a torque setting for the nuts with the oem style like you have. That's what I would do to take all the guess work out of it for you.

I have the non pedestal mounts just the bolt type but again normal 20Ft pounds to tight, so be complete

rentascout,

Do you have the cam kit number? You did the right thing by purchasing the cam, rollers, valves, and springs as a matched set. That does take a lot of guess work out of trying get everything right. What does the instruction state?

http://www.enginelabs.com/engine-tech/engine-tech-flat-tappet-lifters-still-viable-in-performance-engines/

Excerpt: Friction reduction and profile shaping are the roller tappet’s distinct advantages over flat tappets. Rolling contact surfaces enjoy a lower coefficient of friction than sliding surfaces; which is an important factor in a factory production engine that needs to balance power, fuel economy and durability. But the overall friction reduction is not as great as expected, because the similar-style lifter bodies generate the same drag within their individual bores.

So, flat tappet type lifters are still a valid system today.

Checkout this Y-Tube-I believe this is what you are looking for!

Cam Kit CLP32-221-3/

 

[mustang7173]

All,

Cam Specs:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=841&sb=2

Nice cam for just good ole driving with just a little kick.

mustang7173

 

[rentascout]

Well numbers match with everything I need, however one of my new rockers shows up with no oil hole, I was making sure everything was oiling right via pump and I thought I had a bad lifter but no the dang rocker had no hole. Gotta laugh at that