actually low lift flow IS quite inportant - it helps start the movement/flow into the cylinder! your mid lift improvements are quite nice. I have a suggestion Back Cut your valves the small backcut can really help low lift/ mid lift flow. peak flow numbers are what people advertise but the valve only sees peak once in a cycle and it sees the ramp up and ramp down twice! GOOD luck with your project, I signed up here JUST to watch this post!!!
I re-ran the flow with the manifold and TB fitted and the low lift flow came back....remember htis is how I did all the origiunal flow work and optimized the set. It looks like the .300/.350 is a bit lower than it could be....I need to go back through my notes and see where the exhaust valve problem was...or maybe I'll just sink the exhaust valve and quit thinking about it. I realized this morning that I had done all my original testing with the test valves I made but yesterday and today are proper valves that I bought. These are 5.5mm stems, honda car. I just ordered a pair with 5mm stems from the honda ATV that will work with all the shim under stuff (I think). This all looks pretty good so I'm going to try and not let my OCD slow things up too much trying to make it better...remember the goal was 160 Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Now you went and made me spend the morning looking at headers! It looks like only a few makers are using the 1-3/2-4 or 1-2/3-4 pairing and it also seems the high end ones are pretty complicated. They go 2 inot 1 the an H pipe followed by 8-12" of straight then the final 2 into 1. I think these designs only work when something else is not quite right with the engine set-up...no matter as it doesn't apply to a 6 as far as I can figure.
I'm not sure about the low lift flow. I have more duration in the cams than I really wanted so having the very low lift flows a bit low should help compensate for the long duration...maybe. The sim software says this works out but who knows what the dyno will say. When the 5mm stem valves get here maybe I'll try backcutting the 5.5mm and see what it does. I just mathed the valve seat ID area vs the perimeter area again and it looks like .253 is where the the cross-over point is where the perimeter area exceeds the seat ID area so that explains the bend in the flow curve at .250 lift.
low flow will help cut power but wont change the timing of the sonic wave that travels up the intake port when the valve opens. you will lose (potential) power but dont gain drivability. in fact having the port/system more efficient will help mask the larger duration by giving you better power all around. do not open the throat area under the valve to more than 91.5% of the valves size. LOVE the project! Keep up the good work
I agree that right is right and everything else is wrong. I would take more .050 flow, but I don't want to lose elsewhere to get it. You are absolutely correct that the valve is at .050 twice, but it doesn't spend much time there. With the cam I'm running and the lash at .010, 0-.050 lift is about 30 degrees, so 60 total and the air is hardy moving for most of that, but it spends something like 85 degrees above .400 where the air is at or near peak velocity. It seems to make sense to stay focused on the .200 and up number that represent about 2/3 of the duration. Either way though I think I have enough air at this point to keep the engine pulling hard past the rpm point where my nerve will give out....I think 9000 is as high as I'm prepared to go and the computer says the peak is around 9k but it will pull hard right to 10000. I'm actually kind of hoping the mufflers stop it up a bet so there is no point in going past 9k and I'm not tempted. The throat is at 85% of the valve size. I'm using a seat cutter with a R-45-R and it seems to like the throat to be in the 85-87% range so I'm trying to stay there. There might be something to be gained by going to a more standard 3 angle, leaving the throat at the current 29mm and using say a 32 mm valve instead of the 34 that I have.....but at this point I hate to mess with it anymore because it seems to be working....at least on paper. My big point of confusion right now is the exhaust side. The standard "rule" I've always heard for higher rpm engines is that the exhasut flow should be 75% of the intake. But I knoe that the standard is also to have lifts and durtations of intake and exhaust about equal. I have a net lift of .443 intake and .408 exhaust (I'm fitting larger OD buckets to the intake side so more lift is allowed) so I'm thinking this 75% flow ratio should be applied at the lift ratio making the effective ratio .75*.443/.408= .81.4%. My software (dynomation5) says I gain about 30 hp on top with the extra exhaust flow without giving away anything down low.......The math seems right ......but I don't know that seems pretty high and the computer says going to 85% adds another 10 hp but that just seems crazy high to me and likely to mean a lot of air and fuel end up going out the exhaust pipe. I’m thinking the 81% is as high as I would be willing to go….I need to think about this some more. I've got a pair of 28mm valve to try...maybe I'll just though them in and see what I get. I think 29mm is more the standard with 34mm intakes so I don't expect they will be too big....but then there is that lower lift think so I may need to go a bit bigger. More to ponder. Thoughts?
Yep. Busted - Got an 85 RG500 in the shed next to my 81 Katana and my RGV250SP engined Cagiva. Sorry to have side tracked you! It's largely an attempt to widen the powerband on something that make 160+hp/l and revs to 13,000rpm - seems to work though.
No, No it good......It seems like I don't read anything anymore. I stopped buying car magazies about 10-15 years ago and I'm starting to find I'm pretty out of the loop these days. I'm back from Holiday visiting so I guess I need to get back ot butching the TR heads.
I got Forza 3 for Christmas and didn't see the 308 with the V12 conversion in there. This is all photoshopped isn't it?! LOL Merry Christmas guys, wonderful work Mark. Please keep working on this absolutely insanely beautiful project. Laters, Brian
Forgive me if this has been mentioned but what are you considering doing for the rear suspension? I suspect there is more than just a trivial weight increase. Uprated dampers and springs? Another point I may have missed, I assume you've calculated a length for the runners if you are not using VIG? I guess this is am even multiple of the wavelength for a given RPM say 6000 or so? I don't mean to challenge you, just very interested. You seem to have some great facilities available to you at home and to have really done your HW. All in all, very interesting.
I got a little work done. I had a fixture I made for opening the valves on a QV head so I adapted it to the TR heads. I cant actually use it yet because I dont have any type spring retainers for the intake valves yet ..but Im ready now when I get to that point. The rest of the day and it looks like a good part of tomorrow went to installing a sink in the shop. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
I think its been talked about before but I already have significantly stiffer springs in the car and the rears were borderline too stiff compared to the front. I want to try it with the new engine before making any changes as it might be about right. The intake length Ill start with is what the software likes second best. Best seems to be around 17.5, second best seems to be right around 12.2. The primary must be around 35 then, 17.5 the secondary and 12.2 the 3 harmonic.
Oh surely he can do better than that ^, what with all those spare parts laying around... Mark, been lurking on this thread for a while, and although I'm not the engineering type I sincerely appreciate your love of taking something apart, tampering with it, and (well, potentially) putting it back together. Truck on friend!
I wish I could say I was installing something cool but its just a plain old laundry sink. Lana had me pull it out a couple years ago because she found one with a cabinet she liked better so this one has been just sitting in the basement. .because there were no pipes to connect it to so the free sink is costing me $120 at lowes for stuff and 6 or 8 hours to do it. But its nice to come upstairs with clean hands and Victor will play water (and let me work) for hours if theres a sink available. At some point I need to put a bathroom on the other side of the basement. We had that plumbing roughed in when the house was built. Once I get to this project I can live in the shop since I already have the beer fridge
No no...then I'd never get any work done. The original plan was for me to take 1/2-2/3 the space and build a theater and exercise room in the rest......but that was a long time ago. Now I'm thinking who wants living space in the basement really? Better that the basement stays a shop then I build a bigger better garage and put the exercise room and mud room extension in the old garage space then the theater, a play room and maybe another bedroom or 2 can go in the attic so all the new finished space actually counts as living space square footage so it's a much better investment.......I'm just looking out for Lana's best interests I'll do it in my spare time with my spare money
The sink has cause a serious problem. I put the sink in the corner were the metal was so now the metal is on the floor needing a home. Lana says no more shelves until I clear up what I have so now I need ot clean the whole basement before I can have a shelf for the metal and I can't just leave the metal in the middle of the floor....she treicked me!
The ebay (AKA pay for the cams) pile is getting pretty big and freeing up a lot of shelf space but I don't think I'm all that close to actually paying for the cams. I'm going with the "if it isn't worth $25 on ebay it isn't worth a place on the shelf" rule....and the trash pile is at least as big as the ebay pile. This will be it I guess on stuff to sell then the actual cost of the project will start to become clear to Lana. I'm thinking of painting the walls and floor to brighten things up and keep the dust down.....I don't know what to do with the ceiling though. I guess insulate for sound, plastic to keep the smells in the shop and drywall....that makes it seem like a big project though. Maybe I'll just skip it and get back to the heads.
