Restrictors

I built my first BBF a couple of years ago, and my only regret is that I didn't start many years earlier, these engines are amazing! My first build was a fairly strait forward 466 no street use, just 1/8th drag racing. Nothing too special, but enough for a little less than 3K lb car to run low 6s. Of course if a little is good more is better, so I have the motor out for a refresh and changing things up a bit, bigger cam, more head flow, more RPM. This brings me to my question, I learned a lot building my first motor, big thanks for the wealth of knowledge on this site, and Paul and Scotty especially for their advice! (as well as their tolerance for dumb questions!) As I continue to follow discussions here, the topic of oil restrictors got me thinking about if I need to make some changes to my oiling system, my motor now has Paul's mods: increasing oil passage diameter from the pump to the filter, then from the filter to the front cam journal and the 1/16 oil hole to the distributer gear. other than that good windage tray and scraper high volume pump and pick up, that's about it. As it was set up before I never spun it past @6,800, now I'll be shifting around 7,200 possibly a little higher, are additional mods such as a restrictor plug in the cross over or restrictor push rods necessary? when I tore the engine down this off season, I put new bearings in it, but the old ones looked good enough to put back in, so for the power level the old setup produced, I see no indication it needed anything more, thoughts/advice?? Thanks again for all the knowledge on this site and people that are actually willing to share it!!

Quattro wrote:I built my first BBF a couple of years ago, and my only regret is that I didn't start many years earlier, these engines are amazing! My first build was a fairly strait forward 466 no street use, just 1/8th drag racing. Nothing too special, but enough for a little less than 3K lb car to run low 6s. Of course if a little is good more is better, so I have the motor out for a refresh and changing things up a bit, bigger cam, more head flow, more RPM. This brings me to my question, I learned a lot building my first motor, big thanks for the wealth of knowledge on this site, and Paul and Scotty especially for their advice! (as well as their tolerance for dumb questions!) As I continue to follow discussions here, the topic of oil restrictors got me thinking about if I need to make some changes to my oiling system, my motor now has Paul's mods: increasing oil passage diameter from the pump to the filter, then from the filter to the front cam journal and the 1/16 oil hole to the distributer gear. other than that good windage tray and scraper high volume pump and pick up,  that's about it. As it was set up before I never spun it past @6,800, now I'll be shifting around 7,200 possibly a little higher, are additional mods such as a restrictor plug in the cross over or restrictor push rods necessary? when I tore the engine down this off season, I put new bearings in it, but the old ones looked good enough to put back in, so for the power level the old setup produced, I see no indication it needed anything more, thoughts/advice?? Thanks again for all the knowledge on this site and people that are actually willing to share it!!

Bushing the lifter bores is the only type of restriction I would put anywhere in the oiling system and only then if you enlarge the main oil gallery to 5/8" beforehand, (front to back).
Restricting pushrods, (about .025" hole), CAN be used with a roller valve train but, I have not seen the NEED for them.

I can not give you any advice on the oil mods to the block as I didn't do anything to mine when I built my 552. But after running it a few times I noticed my oil pressure dropping at the end of a run. I changed out my oil pan to one with baffles and windage tray thought it was the pan it still did the same thing. I talked with Rich aka Boss 429 so I bought new push rods from Smith Brothers with restricters with the size restricters he suggested. That fixed my problem. I am running a solid roller cam and crane gold rockers. I shift mine at 7000 with rev limiter set at 7200. Maybe this will help you as I said I don't know about block mods but if you do run restricter push rods make sure you put them in right they go in only one way.

Thanks, I'm running a roller cam also, I'll try the restrictor pushrods, once I figure out pushrod length for the new top end, I'll order a set. Two more questions, I was reading somewhere on this post that only 8 are used? if so which bank would the restrictors go in and where did you get yours?

Is the engine experiencing unusual oil pressure symptoms?  Sounds like everything's working just fine; if it ain't broke don't fix it.

Paul, you are the voice of reason, thanks. Yes, the engine was working great, the only concern I have is that the new setup will be running possibly as much as 700 more RPM, instead of shifting at 6800 now it might be as high as 7,500, but since it's an 1/8th mile car, time at that rpm is short, so I'll take it out see if oil pressure starts dropping at the end of the run, if so, then I'll address the issue.

I have restricters in all 16

Thanks for the info. on the pushrods, I think I'll take Paul's advice first "if it ain't broke………." If I do have issues with the new setup, I'll give the restrictor pushrods a try.