Are those intake ports big enough to expose the end of the side seal to the port? If so I'd be worried about the sharp transition on the closing edge of the port.

 

Hey, I just talked to Andy at Camden and he said that for a normal street application like mine it really isn't necessary to raise the oil pressure. He said for race applications it's a good idea.

Rich

 

Ok, I'll go back and rethink if I want to just build the engine now or grind the rings. The ports are sort of oval shaped on the inside and the horizontal edges are the only ones that could slow exhaust flow. The top and bottom aren't perfect, but there are no sharp edges. I know it's not ideal, but my other R5 engine with the backwards D ports in my other REPU has pretty much as much power as my friend's supercharged REPU from about 4k up. It has much milder intake ports too. I may not even worry about it... I'll have to think about it for a while.

The thickness of the 20B-only intermediate is 80mm. My engine is still together so I can't tell you anything about the stationary gear. It'd be better to ask in the 20B subforum.

REVHED, yes they're big enough to expose the side seals. I've added a 45° bevel which doesn't show up in the pics very well. The ports I copied from have a sharp tiny 45° edge so I improved on it.

 

Well now I'm confused because when I spoke with him, he told me they usually go up to .200. He didn't say anything about race vs street. My bearings aren't brand new so I'll just go with higher oil pressure than stock.

 

I like the work.. but I woudn't have the patience for it.. maybe if i could just bolt it to a milling machine which I have at work then I'd do it... I'd want to test it on a dead housing befor eI try it on a good one though.. and if I did wan to go through all that trouble.. I'd build a peripheral port and make my life easy.. of course it owudl be stupid to try it as a daily driver

 

Great work Jeff!

( i havent seen Nitrated housings in many years!)

I really like your exhaust port.The edges are well shaped,and the size looks very nice,without overdoing it.Your intake ports look very well balanced,with the runners being left a bit rough

karis

 

Cool. Looks like you did a really good job then.

 

Thanks everyone. Those ports took days to do. I'd work on it until the awkward position in which to do the careful shaping fatigued me to the point where I'd start to make mistakes. Then I'd take a break and try again later. I can only port outside and the weather here's been less than agreeable too. I tried porting in the garage once; big mistake.

karis, do you only deal with early plates? Aren't they harder to port since the iron is harder all the way through?

REVHED, I built the stack last night and it feels a lot smoother than a previous engine where I used Vaseline on the bearing surfaces due to convenience. This time I used oil on the bearings and I'm glad I did. Anyway, there is absolutely no feeling of catching the side seals on the ports. Of course I doubt I'd feel anything if there was, but anyway this engine feels awesome when I spin it by hand. It even has a bit of a breathing sound with only a little vaseline on the rotor housing surface. I'm going to pour a little oil in there and crank it around by hand some more.

karis, didn't you once have an engine that was ported so large that it couldn't be started with a starter? Didn't it have to be roll started? I have to admit these large ports of mine are starting to make me think about stuff like that.

I'll get a couple pics of the sandwich today.

 

Why is it a mistake to port in the garage? Just curious.

 

I bet his garage is dark and not very well ventilated! Porting usually makes dust and metal pieces fly.

 

For those reasons. I also had a computer in there that sucked up some metal dust.

 

Mr Jeff :I mostly dealt with early plates,as they were allmost unlimited.Not much left of them now though! :-) From my experience :they are harder on the bits,and take more time.However,taking more time,they allow a little more room for mistake,as the material moves slower.

Thats correct Jeff.The exhaust ports had to much overlap,that it wouldnt start at slow rotating speed.The intake port closed way past 70deg ,and the total exhaust port timing was more than that of a Monster port.

From what i can see from your pictures,your exhaust ports doesnt look overdone.They were increased a big amount,but still within boundries.

As you know,a smaller exhaust port will be less harsch on Apex seals.But as it will be for your Repu,i guess you wont be revving it 10k right>?hehehe

karis

 

Only up to 8k.

Here's a quick shot from before I put the front cover on. I sometimes think maybe I should have painted the irons. This engine didn't have a waterpump when I got it, and it looks like it was leaking from the weep hole. Oh well, it adds character lol!

 

Nice work jeff......
keep it coming!!!!

 

Thanks. Here are some more for your pleasure.





It's so hard to capture ports with this camera. Anyway, you can see differences in the way the grain (cut) of the ports reflects the light. I can barely make out the side seal on my monitor. The oil seal is pretty easy to see.

 

on the exhaust port i would have gone wider then larger

 

Are you talking about the rings? I went as wide as a T2 on the inside. If I removed the rings there would be a serious mismatch where it enters the header. I could have smoothed the inside of the rings a bit, so I'll do that next time.

 

been following this one since the beginning. it's great buildup, Jeff. i can't wait to see what it does after you light it up and break it in.

 

Me neither.

Here it is next to another engine I rebuilt recently. All it needed was a soft seal and spring replacement. All the hard seals and even apex seals were fine. I'd never seen such little wear on R5 rotor housings before. Kinda ugly compared to my engine though.


And here it is in the truck. Wow, these pictures turned out kinda weird looking. I don't have access to the digital camera today, so these'll have to do.


What a beautiful exhaust manifold. Very rare, but I'd still prefer a header. I'll get one soon.

 

I forgot to mention I went with .160" washer thickness in both oil pressure regs.

 

is this sarcasm? what's so rare about it?

what are your exhaust plans when you're done?

 

If that was not a 13b i'd say that exhaust manifold was from a 79.

 

RB header, Rotary Engineering glasspacks, maybe an RB presilencer if necessary.

 

Darn,this thread made allot of progress when i was off last week!

Nice work Jeff!The engine looks great!(your a clean guy arent you?)

karis

 

That's some slang I've never heard before, but thankyou.