Cam and lifter question

N

Nevadasmith

Active member
So I built an awesome log head 250 for my bronco.......6000 miles on it and I love the performance, everything is great, except I used a clearance gasket set.....valve cover, pan gasket, and rear main are all leaking...... totally my fault!!! I just got cheap!!!! So the engine needs to come back out....but
The other day I picked up a 250 short block for $100. It came with a story..... So the story is it was built for a mustang, with a vintage inlines aluminum head, and made 3 Dyno pulls, the builder was disappointed in the numbers and parted it out sold the head then the short block.
The guy I bought it from tried to put it in a falcon only to realize the bellhousing was different.

Here is the question, I checked the cam spec with a dial indicator, it's very close to the one I'm running, but in the block there was only 3 of 12 lifters.....is it okay to run new lifters on a previously run cam???? ......or should I just buy a new cam and lifter set? Sorry so long winded!!! Thanks for the advice!
 
Yes you should install a new set of liters! Here are the rules I use on new and used cams and lifter sets that has always worked successfully for me. In all the below cases also be sure to lube the cam and lifters properly during the install.

1. A used cam if its still in good usable condition can have a new set of lifters installed, it will also need to be broken again just as the cam manufacturer recommends for a new cam and lifter set.

2. A used cam and used set of lifters in good condition can be reused as long as the lifters are kept in the same order so they each go back on the same cam lobe. No rebrake in is nessiary.

3. When installing a new cam you wil always need to install a new set of lifters, and they will need to be broken in as to the manufactures instructions.

Hope that helps you good luck (y) :nod:
 
So I knew rules 2&3 and they are hard rules!!! It was rule 1 I was struggling with, the internet is all over the place on that one!!!!! But I think I'm going to try it!!! The mystery cam is the same lift .420 as my cam but afew * more duration, mine is a 280@.006 this one is 284@.006 mine is 212@.050 this one is close to 216@.050.......
I have been running out of umph @3000 rpm .... slightly bigger cam should tell me if it's head/log/carb or cam/cylinder fill problem??? Right?
 
Nevadasmith":2yohygio said:
So I knew rules 2&3 and they are hard rules!!! It was rule 1 I was struggling with, the internet is all over the place on that one!!!!! But I think I'm going to try it!!! The mystery cam is the same lift .420 as my cam but afew * more duration, mine is a 280@.006 this one is 284@.006 mine is 212@.050 this one is close to 216@.050.......
I have been running out of umph @3000 rpm .... slightly bigger cam should tell me if it's head/log/carb or cam/cylinder fill problem??? Right?
Click to expand...

Yes maybe! A 250 can typically handel a much bigger cam than a 200 and still be on the mild side. But to answer your question correctly I would need some additional info on your build combo such as the head and carb you are using. (y) :nod:
 
Sharp eyes pmuller9, X2 yes I agree with that statement! Looks like an excellent build up on your 250 short block plus the best there is in a stock log head. The single 1V YFA for sure isn't enough carb to feed your combo and allow it to breathe at the higher RPMs, so its going to be the very first limiting factor. Also from personal experience (with my 1977 Maverick 250, C4, 3:00 rear gear, one size over on tires) I can tell you that a single YFA wasn't even enough carb for that almost stock 250, it hit the wall at 67MPH. A 3 X 1V triple using YFA's could work well though or go back to that Motorcraft 2150 sounds like it needed some work though like a float and needle and seat. (y) :nod: Edited
 
The log will need to be opened up so you can run a 2 barrel carb directly without the adapter.
 
Hi, you should not run out of power at 3500 RPM with that set up.
Your cam centerline seems way high. Have you degreed the cam?
Good luck
 
Any updates on your build. Yes you need more carburation.
You stated you used 2.3 HSC pistons??
If so do you realize the wrist pin in them is .090" offset. Would help low end torque on a 200, but with a 250 the long stroke takes care of the torque.
If the rings are already seated DO NOT REMOVE pistons. If you hone & install new rings that is the time to have a machine shop install the pistons with the notch toward the rear.
That will enhance high mid to top end power.
You also need a serious recurve on your DS11.
 
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