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Beginner 300 moderate rebuild

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buckingbronco
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Beginner 300 moderate rebuild

Post #1 by buckingbronco » Sat May 23, 2020 8:03 pm

This post is to document our progress on our 1980 Bronco rebuild that my son and I are doing.
Image

The primary reason for the rebuild was excessive blow by that was covering the engine bay with oil let alone burning it.
Since we had to repair something on the inside we will also be upgrading intake to Offy dp, efi exhaust manifolds, 4bl Holley 8007 carb, improved cam(tbd), and do some mild porting.This will hopefully improve hp performance so going down the highway is easier.

We already received a lot of great advice on prepping for the build from this post
viewtopic.php?f=2&t=80980&p=630364&hilit=prep+for+rebuild#p629975

I attached images but I am not sure how to insert them... :?: UPDATE I have now learned how to post images and I have updated this post

We took the front end of the truck off vs taking the hood off since we wanted to do some rust restoration work on the front end.
We followed the removal steps from the Ford 1980 engine manual...only real question was how much to raise the transmission to get the engine off. We had to raise it about 2-3 inches to get the engine mount bolt to clear the frame before we could get the engine off the transmission. It just took some iterations on the jacking.

There was an interesting gasket for the air intake to the carb.. old mason jar lid...which will not be needed in our rebuild :lol:

We had guidance to take a picture of the distributor with #1 at TDC and those are attached as well.
Image

after we had the engine on a stand (HF 4 point stand is working well for us so far), we removed the head to find that this engine was already rebuilt once with sleeve inserts. UPDATE: probably not sleeved...what we saw was just outline from head gasket
Image
We also saw from the head picture that #2 cyl had much heavier deposits as you can see on the head picture.

We rotated the engine... and quickly found out that the hydraulic lifters can just fall out... rookie mistake... we removed and labeled them the best we could.. there are 4 that fell out that may or may not be in the right position. :oops:

We then took the pan off and saw some ring parts/chips in the bottom of the pan.. maybe a dozen small 1/4 pieces.
We took off #2 piston and found the broken ring with the guides in the piston also broken...
Image
We took the rest of the pistons off and #1 also had broken rings but the rest of the pistons were all good.
The rod bearings almost all 5/6 had some score marks... I'm guessing pumping fragments of rings and piston is not the greatest for them. :|

So now the questions for some wisdom from the group...
1- Can you bore out a sleeve or are we now looking to find a new block? I intend to take the block to the machine shop Tuesday to get their opinion. The cylinders all look good from an appearance standpoint. you can see cross hatching... there are some scratched that you barely can feel with your finger nail. see img3403 in attachments
2. We have not yet removed the pilot bearing from the crank... do we need to do that or does the machine shop do that? and is that something that you automatically replace or do you reuse?
3. We have not yet taken the timing gears off. Do we need to definitely take them off before sending crank to the machine shop?
4. Do we take the rocker arm studs off or leave those on?
5. It was recommended to remove casting marks in the block... I see the ones on the main web for the crank. see img3400 and I'm guessing the ones underneath the camshaft will also be obvious.
6. we will also be doing some mild porting but I was going to start a separate post for that to make sure we dont mess that up.

Thanks for the help again!!
Last edited by buckingbronco on Fri May 29, 2020 10:12 am, edited 1 time in total.

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bubba22349
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Re: Beginner 300 moderate rebuild

Post #2 by bubba22349 » Sat May 23, 2020 8:50 pm

Not a problem on the lifters being wrong unless you had planed to reuse them along with the cam, since you said your going with another cam grind then you will need a new set of lifters to go with it. The timing cover will need to come off to remove the crankshaft and the camshaft removed if your taking the block in for cleaning and boring with the crankshaft. With the metal that when through the oil system the crankshaft will need at least a polish or it might need to be ground undersize depending on its condition.

1. Yes a sleeve can be bored out

2. The pilot bushings can sometimes be reused it would depend on if it shows any wear in the hole, as far into this as your going you probably should just replace it with a new one they are low in cost. You can remove it by packing it with wheel bearing grease the use a Rod that just fits it the hole strike end with a hamer to Hydrolicly push the bushing out you will need to pack the grease back in several times. You can also use a slide hamer tool or even have the machine shop remove it. Good luck :thumbup: :nod:
Even a bad day Drag Racing is still better than a good day at work!

Current project is a 1988 John Deere 420 Garden Tractor I need a few small parts to get it fixed, plus some cosmetic items, maybe a few attachments, if you happen to have or know of JD 420 parts would welcome the help!

My Ex-Inline 6 Fleet 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

sdiesel
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Re: Beginner 300 moderate rebuild

Post #3 by sdiesel » Sun May 24, 2020 1:33 am

you can leave many of the parts you are concerned about right, where they are .
when crank goes in the caustic, if it does, the bushing disappears or the shop removes it before tanking. same with all other concerns. it takes but a moment for them to do it. it takes a lot longer for you to do it. get them to pull and install cam gear too.

if you grind casting flash do so early on, so their hot tank will hopefully clear out the metal shavings. the product called Awesome at dollar tree is, well, awesome for cleaning carboned castiron. drain oil, turn her over leave pan on, fill up the entire engine block with the stuff wait till morning turn block back over (engine stand inside a kiddy pool) and finish off with a garden hose and nozzle for a remarkable clean.
im assuming you still have head on and lifter cover sealed etc.

but most importantly: find a very good machine shop, spend the money, and if its a really good shop, have them assemble the long block for you. If you want the experience of putting together an engine, do so on the junk block.
the warmth you might feel by doing this in your shop becomes an aggravation if you get something wrong....
am i guilty of this? on almost every engine, I have had to backtrack into a finished block to double-check or change something i thought was a good idea
" did i forget to chase those threads ? or did i torque the cam retainer properly'' yea it's irksome, and when it's your first and you are hoping for a reliable run-forever machine.And likely its more expensive to do it yourself. if, for example, you wipe a cam. I have. i have done it.
. i ain't sayin your stupid like i am, but these things do happen.

sleeves: i personally would search for a new block. there are many available cheaply and likely less expensively than reworking a sleeved block. And you are relying upon the work of unknown individuals who originally sleeved that block to support the very expensive work you are about to do to their work....

I have found a superstar machinist. i turn the mess over to him ( mess figure of speech, he dont let greasy parts in the shop. i have to disassemble and tank or spray wash first). and i get back a complete long block in a month's time with a guarantee, something i won't get if i do the work myself. labor is but a paltry 500 or so to assemble. 2000. for complete machining roughly. piston hanging and custom work is more.

this is not universal advice. there is talent on this board that rocks, and they HAVE to build it their way. But in most cases their way is pretty specific and aiming for a precise outcome.
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

BigBlue94
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Re: Beginner 300 moderate rebuild

Post #4 by BigBlue94 » Sun May 24, 2020 12:34 pm

1. Does it really have sleeves in the cylinders? That's indicative of multiple rebuilds or a serious crack.

2. 3.& 4. Most shops want to do the teardown themselves, so they know what's correct, and they can see how the engine was treated. I sent my complete shortblock down, and the head, since I'd already removed it for a leaky head gasket.

5. Not necessary, but a good idea. It should be done before the block gets a final cleaning.

6. Porting without a flowbench is risky. But the guys here can help with that. Lengthening the radii and smoothing the bowl transitions is the biggest help.

Pics cant be attached here anymore. You must host them somewhere, like Facebook, imgur, supermotors, etc. Then copy and past the [img] tag here. When entered in the text box, itll look like this. I use supermotors, and they provide a copyable img tagged link.

[img]picture.url.whatever[/img]

Alternatively, you can copy a picture URL, paste it in the text box, and highlight it. Then click the small button above the text box that looks like a moon and two mountains. That will add the img tags to embed it. Or you can type the img tags on manually.
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #5 by buckingbronco » Fri May 29, 2020 10:42 am

Thanks for the extra questions about the sleeving...

I talked to our machine shop and he doubted that all 6 cylinders were sleeved... which is what we observed as a dark ring that does not rub off around the top of each cylinder (see the pic in the first post - I updated post with pics now that my son showed me how to host a picture on imgur...he said that it was probably just deposits around head gasket... Sure enough the ring match the head gasket perfectly... rookie mistake 2 :duh: We took the short block with the cam and crank still in place down to him. He also looked at the bottom of each cylinder and did not see any lip or transition on a sleeve and felt pretty confident that it was not sleeved... but will tell more after the block is tanked and magged.

In our rush to get the block to the machine shop we did not grind the casting marks off. So we may need the machine shop to do that if cheap enough.

We hope to hear from the machine shop sometime today on measurements, block condition etc

Now we need to decide on the camshaft. My son's preference is the Comp 268H based upon what other posts reference. The info below is pasted from the camshaft thread on the ones that we are looking at:

STOCK FORD
.397”/.397” 192/192 268/268 110deg 18 70 58 30 @.006”

COMP CAMS
260H (66-237-4) .447"/.447" 212/212 260/260 110deg
268H (66-248-4) .456"/.456" 218/218 268/268 110deg

ERSON CAMS
E270101 (RV10H) .448"/.448" 208/208 280/280 110deg (Actual .006" duration is 270)

SCHNEIDER CAMS
262-70H (13918) .464".472" 208/214 262/270 110deg
135H (13919) .472"/.472" 214/214 270/270 110deg

We were looking for improving HP over the mid range to help with highway driving and not loose torque at the low end. and get some mild grumble sound but not excessive.This is a daily driver and we hope to stay with 87-89 octane gas.
There was a recommendation to use the ERSON RV cam.

So I guess the question is what is the performance difference from the Erson cam and the Comp 268H?
What are we increasing or decreasing?

Are is there another cam that is a better fit? or compromise?

Thanks

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Re: Beginner 300 moderate rebuild

Post #6 by pmuller9 » Fri May 29, 2020 11:35 am

The Comp 268 will give you a little lope at an idle and let you run 87 - 89 octane gas if the compression ratio is below 8.8.
What pistons are you going to use?

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #7 by buckingbronco » Fri May 29, 2020 12:27 pm

Pmuller
I believe you recommended these pistons...

The popular piston is the Speed Pro H519P. Deck the block so the piston is almost even with the top of the block at TDC.
Should give you close to an 8.6 compression ratio.
https://www.summitracing.com/parts/slp-h519p/make/ford

When you say 'almost even with the top of the block' is that the same as '0 Decking'?

I used a graduated cylinder to roughly measure the existing pistons and their dishes look to be somewhere near 17-20 cc.
I did not put a piece of plexi glass on top be sure it was flat so I had to read the meniscus overage a bit.

I thought the Speed Pro H519P were 25 cc dishes each?

on the COMP 268H cam... which parameter is giving it the lopey sound... i thought that lob separation did that? ... but all of them are at 110deg of lob separation.

thanks
Brian

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Re: Beginner 300 moderate rebuild

Post #8 by pmuller9 » Fri May 29, 2020 12:49 pm

Brian
Yes I did recommend the Speed Pro H519P. I just didn't remember. There are too many projects here to keep track of.

Yes on the "0" Decking.

The lopey sound is related to the valve overlap period which has to do with the LSA and the lobe duration.
(Intake Lobe duration + Exhaust Lobe duration) divided by 2 minus the (LSA x 2).
(218 + 218)/2 - (110 x 2) = -2
This shows that the Comp 268 cam has 2 degrees before there is overlap at the .050" duration specs.
On the 300 six as you approach 0 degrees .050" overlap you start to get lopey idle.

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #9 by buckingbronco » Sat May 30, 2020 11:12 am

Okay so for the Erson the math would be ...
(208+208)/2-(2x110)=208-220=-12.. so the Erson cam would not have ANY lopeness?

The COMP 260H has a -8 by the same calc... so would it have mild lopiness?

And when you say keep the compression to less than 8.8 for 87-89 octane gas ... is that Static or Dynamic compression?

We are thinking that maybe we should go with the COMP 260H or one of the schneider ones like the 262-70H that has more lift and duration on exhaust since the 300 head is exhaust limited? ... that one would be a -9

We were comparing to the stock (what we heard before) of-28 so going from -28 to a -9 should add some rumble but keep good idle quality... right?
or do you need to be close to 0 to get any lopeyness...

I've read a lot about over camming... and last night about the flow numbers for this head (this forum is a great resource...my hats off to everyone over the past years accumulating this)... it looks like you only need about 0.45 ish lift to be at maximum flow... so any of the cams I listed are in the right range to get max flow... Does the Schneider at 0.472 really gain much versus the others at 0.456 ish?

Thanks again for the help on this.. camshaft selection seems to be a lot of art or maybe better said personal choice...
Your guidance will help us not making a bad choice.

thanks again

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Re: Beginner 300 moderate rebuild

Post #10 by pmuller9 » Sat May 30, 2020 1:35 pm

In general the 300 six doesn't have a noticeable lope till the overlap gets near zero but I need to qualify this statement.
The amount of lope depends on the idle rpm. You can have more lope if the idle is turned down or less with a higher idle.
The last cam I installed was 232/232 at 112 LSA and was fairly smooth at 900 rpm idle.
The other part is the tune-up.
As the overlap increases the engine likes more initial timing. It also likes a richer air/fuel mixture at idle.

The only Comp cam I can recommend is the 268.
The smaller Comps have a require a low static compression to prevent detonation because of the relatively short advertised duration.
Go with one of the other brands for a shorter .050" duration.

The 8.8 compression ratio I mentioned was static.
If you want to run on 87 to 89 octane gas keep the Dynamic compression ratio near 7.0

You won't over cam a 300 six with any of the "off the shelf" hydraulic cam offerings.

You will see benefits with a stock head up to .500" valve lift.
The higher lift lobes have a wider duration at mid lift which help flow at lower lifts.

The exhaust actually flows well compared to the intake and doesn't need extra duration and valve lift.
If you go with a longer duration exhaust you dump the cylinder pressure earlier which affects low end torque but helps extend the upper part of the power band.

If you want some lope and a strong low to midrange and don't care about revving past 4500 rpm go with a cam with a tight 108 LSA and idle it at a low rpm.
Howards 280026-08 .448”/.448” 209/209 263/263 108deg

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #11 by buckingbronco » Mon Jun 01, 2020 10:43 pm

After much discussion we are going to go with the Schneider cam 135H
135H (13919) .472"/.472" 214/214 270/270 110deg
per Summit cam calculator on position...
Intake Exhaust
Duration: 214 214
Lobe Separation: 110
Advance: 0
Centerline:110ATDC 110BTDC
Open: -3BTDC 37BBDC
Close: 37ABDC -3ATDC
Overlap: -6

we may loose the lopeyness but we will get some improvement across the power band by increasing lift to 0.472 vs 0.448 and will not shift the power band up as high as the Comp 268H:
268H (66-248-4) .456"/.456" 218/218 268/268 110deg

The other good recommendations were:
Howard
280026-08 .448”/.448” 209/209 263/263 108deg
or Erson
E270101 (RV10H) .448"/.448" 208/208 280/280 110deg (Actual .006" duration is 270)
Our concerns with the RV cam and the Howard is that we may not get the improved highway performance we wanted and the lopeness was a nice to have...

So the next question is do we need to advance this cam or not? and if so how much?

thanks
Brian

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Re: Beginner 300 moderate rebuild

Post #12 by pmuller9 » Mon Jun 01, 2020 11:18 pm

The cam card usually specs a 4 degree advance but a 2 degree advance will be fine.
There will be plenty of torque just off idle no matter what.

The situation is that you only get to change the cam timing by 4 degrees using an off set key in the camshaft timing gear.
You shoot for something in between 4 degrees advanced and straight up and take what you get.
The only way to get an exact cam position is to cut a new keyway in the crankshaft timing gear.

The one reason for not going with the full 4 degrees advance it to keep the DCR low so the engine is not as sensitive to gas octane.
If you have to choose between 4 degrees and straight up I would go with straight up.

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Re: Beginner 300 moderate rebuild

Post #13 by buckingbronco » Tue Jun 02, 2020 8:25 am

When you buy a camshaft kit that includes the timing gears do they put the camshaft gear keyway 4 deg advanced already?

or do you still need to buy an offset key?

We had metal timing gears already and they looked okay so we were talking to the shop about reusing them. but if they are not offset right then that may not make sense.

Pmuller - since you have been guiding us on the camshaft selection, does the Schneider 135H make sense for us if we drop the lopiness need
The schneider site lists the 135H rpm range as 2000-5200(.http://schneidercams.com/135HfordI6hydraulic.aspx)..

but the COMP 268H is 1200-5200 at 218 duration(https://www.speedwaymotors.com/COMP-Cam ... IkQAvD_BwE)

... so I would have thought the Schneider would have dropped the range a bit more below the 268H..
Or are these quoted ranges just advertising opinions?

or am I not understanding the cam selection guidance...from what I read longer duration moves the power band up... so shorter should shift it down..


thanks
Brian
Last edited by buckingbronco on Tue Jun 02, 2020 8:37 am, edited 1 time in total.

pmuller9
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Re: Beginner 300 moderate rebuild

Post #14 by pmuller9 » Tue Jun 02, 2020 8:35 am

If the stock metal gears look good then use them.
You don't know where the keyway on the cam snout will end up giving you for cam timing till you put the gear on to check it.
If it is not close to the needed timing then you figure out how to correct it from that point.

The Schneider 135H is a good choice with a stock head.

Are you doing anything to the head?

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #15 by buckingbronco » Tue Jun 02, 2020 8:44 am

Pmuller - please see my edit question on the rpm ranges quoted ... just for my learning if I am understanding these camshaft specs and impact on performance... thanks for the help again.

We have also recently purchased a used 240 head. In the future, eg not part of this build we would port that head and maybe put in bigger valves and swap the head out... I am assuming we will need to use premium gas then since compression ratio would go up 0.5 more
And we will need to change the camshaft?

Thanks
Brian

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Re: Beginner 300 moderate rebuild

Post #16 by pmuller9 » Tue Jun 02, 2020 9:03 am

You cannot use the catalog claims for rpm ranges or recommended compression ratios.
We go by the many actual build results found on this site and elswhere.

The Ford 300 has large cylinders equivalent to a 400 V8. The ports are undersized for the cylinder size.
What we find is that as you increase cam duration and valve lift the engine responds with more low to midrange torque without loss of off idle torque.
When you install larger valves and port the head you extend the upper rpm range without loss of low end torque.

I put together a 300 with a big valve ported head. 232/232, .534" lift, 112 LSA cam.
It would break the tires loose from 1200 rpm and make power past 5500.

The 240 head has valve shrouding and is not a good option for performance street use.
The only place it is useful is for some racing classes where a 12:1 compression is needed using flat top pistons.
You can get anywhere from 8:1 to 11:1 compression using the 300 carburetor head with a piston change.

Are you rebuilding the 1980 head?
One of the reasons I'm asking is because the 1980 head has non-adjustable rocker arms.

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #17 by buckingbronco » Wed Jun 03, 2020 3:32 pm

We are rebuilding the 300 head with just porting not bigger valves yet... unless you think the bigger valves are a must or a no brainer change to do at this time... eg the cost to do the valve job is the same as grinding to bigger valve size and the cost of the valves is 100$ or so..

So if I understand your comments on the 240 head that we may not need it for street use..

For the 300 head with the FelPro 1024 and SP H519P pistons I thought we would get to about 8.6 static compression.
I need to learn how to calculate the dynamic for the Schneider 135H to see the dynamic compression ratio.

So how do you get to larger increase in compression? I thought the next step was to use the 240 head...

again thanks for the education here.

Brian

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Re: Beginner 300 moderate rebuild

Post #18 by pmuller9 » Wed Jun 03, 2020 3:56 pm

Use your judgement on the head.
If any of the stock valves need to be replaced then might as well go to the larger valves.

The one thing I would replace is the rocker arm studs.
Looking at them you will notice that the top thread is 5/16" and the stud body is 3/8"
The rocker arm nut tightens down on the 3/8 stud shoulder and there is no adjustment.
Pull those studs out and have the head drilled and tapped for screw in studs.

Some raise compression by bushing the connection rod's small end from .975" to .912" and using Ford 351 V8 pistons.
Others like me use custom Autotec pistons.

Here is the calculator for both Static and Dynamic compression ratios.
https://uempistons.com/p-27-compression ... lator.html
Use the cam's intake advertised duration for the intake valves closing point ABDC for the calculator.

Example:
The Schneider 135H has 270 deg advertised intake duration and lets say you want to set the cam 2 deg advanced with the intake lobe center at 108 deg ATDC.
270/2 + 108 - 180 = 63 deg ABDC.
So you would put 63 for the intake closing point

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #19 by buckingbronco » Thu Jun 04, 2020 9:40 am

Okay here is the dynamic calculator results... using the 135H cam... please confirm I have inputted correctly..

One question though.. the calculator said to use the intake valve closing point at 0.05 but the guidance was to use advertised which is closer to 0.06 ...

So we end up with about a 7.2 dynamic compression ratio... which should be good for our application and allow running on 89 maybe 87 gas.

We will ask the shop to replace the rocker arms so we can get adjustable studs..

Thanks for all the great guidance...

Image

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Re: Beginner 300 moderate rebuild

Post #20 by pmuller9 » Thu Jun 04, 2020 9:55 am

You may find that the pistons actually have a 25 cc dish.
Check the dish volume when you get them.

The studs get replaced by drilling and tapping the head for screw in rocker studs with a 7/16" base.
All stock rocker arms fit a 3/8" rocker stud.

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Re: Beginner 300 moderate rebuild

Post #21 by buckingbronco » Thu Jun 04, 2020 10:13 am

with 25cc dish on the head that moves static to 8.6 and dynamic to 7.0

Can I removed the studs in the head now? it would help positioning the head for porting work that is underway.
Im guessing 2 nuts on the top trick?

And if I tell the machinist that we want new 7/16 studs that he will know what to purchase.

thanks
Brian

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Re: Beginner 300 moderate rebuild

Post #22 by pmuller9 » Thu Jun 04, 2020 10:32 am

You should let the shop pull the studs.
The 5/16 threaded part of the stud is not that strong and can break off.

Here is what a screw in stud looks like.
The bottom that screws into the head is 7/16" but the top can be 3/8" of 7/16" fine thread.

https://www.dropbox.com/s/t2mvqrjfx8zbz ... d.JPG?dl=0

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Re: Beginner 300 moderate rebuild

Post #23 by 80f150custom » Sat Jun 20, 2020 9:25 am

buckingbronco wrote:Okay here is the dynamic calculator results... using the 135H cam... please confirm I have inputted correctly..

One question though.. the calculator said to use the intake valve closing point at 0.05 but the guidance was to use advertised which is closer to 0.06 ...

So we end up with about a 7.2 dynamic compression ratio... which should be good for our application and allow running on 89 maybe 87 gas.

We will ask the shop to replace the rocker arms so we can get adjustable studs..

Thanks for all the great guidance...

Image


It might not make much difference but in the calculator you list the head gasket bore as 4.09 but summit lists the head gasket bore as 4.18 for the fel pro 1024.

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Re: Beginner 300 moderate rebuild

Post #24 by THE FRENCHTOWN FLYER » Sat Jun 20, 2020 1:01 pm

The FelPro 1024 has a bore of 4.18".
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

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Re: Beginner 300 moderate rebuild

Post #25 by buckingbronco » Thu Jul 16, 2020 3:35 pm

Im getting ready to purchase the rocker arm studs.
Is there a preference between the 3/8 or 7/16 studs?

and what length do I get?

ideally that would work with stock valves or the larger valves if we go that way in the future.

Thanks
Brian

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #26 by buckingbronco » Thu Jul 16, 2020 5:31 pm

Pmuller

I talked to Schneider cams today (Jerry) and he advised that we consider the 262-70H because our compression was pretty low at 8.8 and that if we went with the 135H it would lose low end power.

Does that make sense to you?

SCHNEIDER CAMS
262-70H (13918) .464".472" 208/214 262/270 110deg
135H (13919) .472"/.472" 214/214 270/270 110deg

The 262-70H gives these cam event timings
Intake Exhaust
Duration: 208 214
Lobe Separation: 110
Advance: 0
Centerline: 110ATDC 110BTDC
Open: -6BTDC 37BBDC
Close: 34ABDC -3ATDC
Overlap: -9

Static compression becomes 8.58 and dynamic at 7.0

Thanks again on the advice

Clinton 78
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Re: Beginner 300 moderate rebuild

Post #27 by Clinton 78 » Thu Jul 16, 2020 10:29 pm

You have me wanting to rebuild my 78 300 now instead of just doing a comp 268h and new gears. Also ordered a 4v intake and 500cfm carb. Headers as well.

pmuller9
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Re: Beginner 300 moderate rebuild

Post #28 by pmuller9 » Fri Jul 17, 2020 12:18 am

buckingbronco wrote:Pmuller

I talked to Schneider cams today (Jerry) and he advised that we consider the 262-70H because our compression was pretty low at 8.8 and that if we went with the 135H it would lose low end power.

Does that make sense to you?

SCHNEIDER CAMS
262-70H (13918) .464".472" 208/214 262/270 110deg
135H (13919) .472"/.472" 214/214 270/270 110deg

The 262-70H gives these cam event timings
Intake Exhaust
Duration: 208 214
Lobe Separation: 110
Advance: 0
Centerline: 110ATDC 110BTDC
Open: -6BTDC 37BBDC
Close: 34ABDC -3ATDC
Overlap: -9

Static compression becomes 8.58 and dynamic at 7.0

Thanks again on the advice

Jerry's advice makes sense except that the 300 six is not that sensitive to a few degrees of difference in duration as far as producing low end power.
You could accomplish the same thing by advancing the 135H four degrees with the intake lobe center at 106 degrees BTDC versus having the 262-70H lobe center at 110 degrees BTDC.

If Jerry would rather sell you the 262-70H that would be fine.

pmuller9
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Re: Beginner 300 moderate rebuild

Post #29 by pmuller9 » Fri Jul 17, 2020 12:25 am

buckingbronco wrote:Im getting ready to purchase the rocker arm studs.
Is there a preference between the 3/8 or 7/16 studs?

and what length do I get?

ideally that would work with stock valves or the larger valves if we go that way in the future.

Thanks
Brian

The 3/8 stud will allow you to use either the stock stamped rocker arms or roller rockers.
A 1.75" Overall Length stud.

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #30 by buckingbronco » Thu Jul 30, 2020 3:29 pm

Next phase while we wait for camshaft and then the machine shop... we are moving onto replacing the exhaust system

I have read what I could on this forum and FTE about mufflers and cats... we've ordered the Dynomax super turbo muffler with 2.5 off centered in and 2.5 centered outlet. Its aluminized to help keep the costs down..

I have looked and looked for 'high flow catalytic converters'.... there are many and when I narrow them down to fit the L6 300 I do not see that they say high flow yet... so...

Anyone with a specific high flow catalytic converter suggestion.? with a part number would be great .. and if I can get it from Advance to use my perk bucks even better... I was able to get the Dynomax from them... so that will help.

I was looking for 2.5 in inlet and 2.5in outlet to match everything up.

thanks for the help

guhfluh
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Re: Beginner 300 moderate rebuild

Post #31 by guhfluh » Sat Aug 01, 2020 4:43 pm

buckingbronco wrote:Next phase while we wait for camshaft and then the machine shop... we are moving onto replacing the exhaust system

I have read what I could on this forum and FTE about mufflers and cats... we've ordered the Dynomax super turbo muffler with 2.5 off centered in and 2.5 centered outlet. Its aluminized to help keep the costs down..

I have looked and looked for 'high flow catalytic converters'.... there are many and when I narrow them down to fit the L6 300 I do not see that they say high flow yet... so...

Anyone with a specific high flow catalytic converter suggestion.? with a part number would be great .. and if I can get it from Advance to use my perk bucks even better... I was able to get the Dynomax from them... so that will help.

I was looking for 2.5 in inlet and 2.5in outlet to match everything up.

thanks for the help

I'm not sure what exhaust manifold you're using, but if you're using EFI manifolds, MagnaFlow may still make a Y pipe with converter. It is what I used in my truck over a Walker because of its nice merge and mandrel bends. I didn't use the converter, but I'd expect it to flow well enough.
1967 F-250 Crew Cab 2wd, 300 6cyl, T-170/RTS/TOD 4-speed overdrive
240 head, Offy C, EFI exhaust manifolds, Comp 268H, mandrel 2.5-3" exhaust, Edelbrock 500, Pertronix ignitor and coil, recurved dizzy. 200whp/300wtq

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #32 by buckingbronco » Fri Aug 07, 2020 9:16 am

After a lot of searching I have ordered the Dynomax super turbo flow model 17733 2.5in offset inlet and 2.5in centered outlet ( to match the muffler we took out on the offsets. the original muffler was 2" I think). We will have to see how it sounds after we get it installed.
My son read that today's catalytic converters are all much higher flow than the original in 1980.. so I found a 2.5in inlet/2,5 outlet cat from Walker model 15038).. it looks to be about the same size as the original one but just had 2.5in vs 2 in pipes. It was listed for 5.4liter engine so after the mods we made to the 4.9l we should be at 5.0+liter... so there should be adequate flow capacity.

Next part is to find a 2.5in tailpipe that fits or make our own... tbd after we get the cat and muffler in place.

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #33 by buckingbronco » Fri Aug 07, 2020 9:26 am

The other item that we are considering 'while we are at it'... is the fuel tank and line..

We basically have cleaned out and restored the engine compartment and have all new components ( except for radiator, alternator, starter, distributor, and fuel pump). This bronco was sitting for several years by previous owner... so we are wondering if we should get a new gas tank and put in new lines ( we have to replace part of the rubber line in the engine compartment already since it cracked during taking the engine out.) My son also noticed that the gas tank seems to build up pressure so the tank vent may not be working eg plugged.

So the question is
1. Do you think it is good to replace the fuel tank and line? eg a good use of $$... the tank doesnt look too expensive and the line can be replaced with braided line
2. If we replace the tank do you recommend converting to an electric fuel pump or stay with the mechanical one?
3. The tank vent line must be plugged so I guess we need to replace that. Is there a device to handle the vent without the carbon canister up front and to still vent the tank?

Again thanks for the good advice from the group.

btw we got the cam yesterday... so headed to the machine shop... getting close to getting the engine back!

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #34 by buckingbronco » Tue Sep 22, 2020 1:25 pm

After several weeks of delay on the cam delivery and the machine shop delays we finally have the engine back.
The machine shop delivered the short block with the crank and bearings and the camshaft installed and the head seperate with the valve job completed
We have installed the head last night and torqued to the final 85 ft lbs spec... but determined that we had mis read the torque wrench setting and actually had it set to close to 95 ftlbs... does that mean we need to redo the head gasket or is the extra torque on new Felpro head bolts not an issue?

thanks for the help

pmuller9
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Re: Beginner 300 moderate rebuild

Post #35 by pmuller9 » Tue Sep 22, 2020 8:46 pm

Not an issue

Is the timing cover installed along with the harmonic balancer and timing tab?

Do you have a dial indicator and magnetic base?

sdiesel
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Re: Beginner 300 moderate rebuild

Post #36 by sdiesel » Tue Sep 22, 2020 8:49 pm

...depends on if your wrench is accurate. I see no problem with 10 over.
The head gasket is unharmed. Just leave it at 95. Further the accuracy of the wrench is quite important.

Tank lines etc. Is personal choice , but examination of rust in the fuel is mandatory. Mechanical fuel pump is best way to go.
Feed fuel line up from pump to carb,and away fro m heat, trying to keep it in fan wash for cooler air.
Doubt the vent is plugged, but very gentle air pressure on the line to the charcoal canister blowing back down into tank,and an ear to the tank fill tube will tell you if plugged. A small magnet on a lite string fed into the tank may pull debris, or it may not, but it is a worthy indicator of tank condition. If any rust at all , drop tank, clean it with water and compressed air, being cognizant of the fact that static electricity could cause spark, and groun ding is important. Replace all rubber hose line. Prefer fuel injection style hose clamp
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

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Re: Beginner 300 moderate rebuild

Post #37 by buckingbronco » Wed Sep 30, 2020 1:04 pm

On the fuel tank system we decided that we had gone this far we may as well replace it. The rock guard had several rust holes in it so we were worried about the tank. We bought the it from Bronco graveyard since it was all the parts we needed. When we took the old tank out we found an old label on the tank from 1994 mfg date so in the end the tank was in good shape just a rusted through rock guard...
The kit went in fairly easily and we added a new fill pipe that had better venting since the old one had issues...

We also decided to remove the head to double check the cam . And we have a new head gasket... so we need to decide if we should still reuse the old gasket and retorque to the 95ftlbs or put in the new one... our torque wrench is brand new and cam calibrated... it was just user error on reading the settings... read the line for the number at the number not the where the line crosses the vertical line... :oopsie: ... at least the time cam all checked out..

We also had an issue with our timing cover with a crack in it by mis using the harmonic balance toolset... so we now have a new one for that...

And when I was dry fitting the EFI manifolds, we ran into a pinch point on the water pump area of the block ... so I ground some of the cast manifold on the front manifold to get it to sit flat... unfortunately I ground too much off and went through the manifold... :bang: somedays you just cant win.... :cry:

We should have all the replacement parts back for another shot of final assembly this weekend...

Thinking ahead I do have a question about the OFFY C header... there is an opening on the bottom of the OFFY C... what is that for and what do I need to put there... it looks like for a heater? or something else?

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Re: Beginner 300 moderate rebuild

Post #38 by 68Flareside240 » Wed Sep 30, 2020 1:28 pm

At least you know your tank is good now. Filling up a new carb with rust is no fun. As for the c it was to mount the stock exhaust manifold to it. No reason to block it. A tip frequently mentioned on here, verify TDC and your balancer/timing pointer while the head is off. :thumbup:

buckingbronco
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Re: Beginner 300 moderate rebuild

Post #39 by buckingbronco » Wed Sep 30, 2020 2:16 pm

Thanks for the quick advice... I found another post just before on the Offy C so it sounds like we leave that space open... or I may make a small piece of sheet metal to close it off... if time allows.

We did go back and check the cam timing to be sure because our new harmonic balancer timing mark did not line up with the timing indicator... Thanks to PMuller9 for the extra help on how to do this...

I pulled out the old harmonic balancer.. and compared to the new one.. the timing marks are in different spots...
which explains why we were getting funny timing readings...and hence we pulled the head to properly check the cylinders and camshaft gear... so at least the camshaft is mfg and installed properly.... now why the harmonic balancer is different... I cant explain....
I will take pictures later today to show you...

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Re: Beginner 300 moderate rebuild

Post #40 by guhfluh » Wed Sep 30, 2020 2:23 pm

*Treed. Some was answered.

I'm not sure why the head was removed to check the cam, but reusing the headgasket is not recommended with a composite gasket. Sealing of the oil and water ports is the concern, as when torqued then removed, it usually leaves portions of the sealer and or gasket stuck to the mating surfaces. Unless it comes off cleanly and possibly some new sealant used, I'd be concerned about leaks or weeps. I wouldn't be as concerned with the cylinder sealing, even though it's still not recommended, as there's some spring still to the metal ring.

I'm curious where you say the interference between the EFI manifolds and any water pump or water neck occurs. I only had some interference with the alternator bracket and intake manifold, both of which were pretty easy to remedy and I didn't come anywhere close to grinding through the manifold. I took metal from both the EFI exhaust and intake manifolds to remedy their clearance issue and from the alternator bracket to remedy that spot.
1967 F-250 Crew Cab 2wd, 300 6cyl, T-170/RTS/TOD 4-speed overdrive
240 head, Offy C, EFI exhaust manifolds, Comp 268H, mandrel 2.5-3" exhaust, Edelbrock 500, Pertronix ignitor and coil, recurved dizzy. 200whp/300wtq

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