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Dual quads, high reving short stroke engine, cool build.
What heads are you using?
So the cam will be a narrow LSA with relatively short duration?
136# on the seat, sounds light. Is this because your using beehive type springs and light hollow stem valves you can get away with this?
no I'm going a step better then a behive spring a conical spring. Seat pressure is right for a solid flat tappet cam if it were a solid roller would need more seat pressure and nose pressure. The cam will be very high duration won't be lifting the valves as high as a solid roller can do. Heads I'm going to buy are trick flows new dhc heads will mod them just a tad. Saw something that surprised me a bit on engine master TV show
they tested an older weind street tunnel ram, a Victor JR and an older edelbrock STR10 cross ram. The victor JR was as I expected not very good. The cross ram was the surprise it was very close to as good as the tunnel ram. They did use one inch open spacers under the carbs on the cross ram. They used the same carbs on both the tunnel ram and the cross ram.
Last edited by Little Mouse; Feb 14, 2022 at 12:06 PM.
Seems like DeWalt and a couple of others have them. I've also seen a peddle switch that plugs inbetween grinder and wall to vary RPM...but I haven't used one yet.
You can use HF inside outside calipers...comes in a set with a bunch of others for about $10. Then use a good digital caliper to measure them.
Pay close attention to the throat area under the seat. Don't go too big...it will ruin the flow. You need to measure that one closely. Typically intake in the 90% range of the valve to maintain a venturi effect.
Here's the aluminum I recently removed from the heads and intake I ported for my project...LOL
JIM
looks like you were serious about changing the heads. So let's see the twin turbo rat needs some more power, this a power addiction that never ends. 😆 I'm guessing they will have the throat sized no more then 90 percent of the 2.02 valve. All I really intend to do is see if I can raise the roof some both intake exhaust see if the bowl at the top by the guide can be widened and I want 2.5 cross section at the pushrod pinch. Wallace racing calculator tells me I need a minimum there of 2.46. I do not have the heads yet to even measure them.
Last edited by Little Mouse; Feb 14, 2022 at 01:40 PM.
Did not know about the conical springs. Just found an article on them. Pretty cool. It also talked about the tool steel keepers. didn't know about them either.
Cool article. I have installed some LS beehive springs from PAC in my DZ 302 and the difference was noticeable. Those tiny little retainers are LIGHT. She revs easy.
The question remains...once you lighten the mass of the valvetrain, you should require less valve spring pressure....but how much less??? How does the light weight valve train affect the valve float RPM limit???
David Vizard showed the weight of a conical spring in comparison to a behive and regular type spring. Far lighter then he showed how they work impressive. Find the video by David Vizard on YouTube and watch it.
I'm trying to figure out how to run a 6 paddle ceramic clutch disk with springs in the center hub on the street. Guy on speed talk tells me I can pull this off by using a light static load of 1600 lbs then the long pressure plate with weighted levers will add more centrical force to clamp down as rpm increases makes sense , if I tried to use a high static load with that aggressive of disk when I let the clutch out off idle could become nightmare on elm Street 😆
looks like you were serious about changing the heads. So let's see the twin turbo rat needs some more power, this a power addiction that never ends. 😆 I'm guessing they will have the throat sized no more then 90 percent of the 2.02 valve. All I really intend to do is see if I can raise the roof some both intake exhaust see if the bowl at the top by the guide can be widened and I want 2.5 cross section at the pushrod pinch. Wallace racing calculator tells me I need a minimum there of 2.46. I do not have the heads yet to even measure them.
Not to take things too far off track...but these are actually Ford Cleveland heads for my 6-71 blown 408" Clevor I'm building to install in the Pinto my Dad bought new and I drove in HS!
Hey..it ran 14.60's with the N/A 2.0L 4 banger! LOL
Should be fun backed up with the Doug Nash crashbox "race" 5 speed and McLeod Soft Lok clutch!
Very nice you sure you can't just drop that off at one of the 15 houses I'm now maintaining any one of the garages will be fine. Yep the 337 I'm starting to build going in a 1750 lb triumph spitfire. When I'm done with it with me in the car should be total weight a little over 2400 lbs. I can't afford to do a 57 vette one of my favorites or a C2. Just my opinion but the C2 dash best looking I have ever seen in a production car, I could just about set inside a C2 all day and night and marvel at how good the dash looks even the vertical radio way cool. While your at it can you drop that yellow car off to. By the way in that pinto any chance your setting the engine back in the frame then setting closer to where the back seat used to be. Crankshaft snout double keyed on your cleavland.
Last edited by Little Mouse; Feb 15, 2022 at 06:50 PM.
Cool article. I have installed some LS beehive springs from PAC in my DZ 302 and the difference was noticeable. Those tiny little retainers are LIGHT. She revs easy.
The question remains...once you lighten the mass of the valvetrain, you should require less valve spring pressure....but how much less??? How does the light weight valve train affect the valve float RPM limit???
Or the same pressure but higher RPM capability. I would assume with less valve train weight that float would occur at a later RPM. How much? I don't know either.
I know the advertised limit of my hydraulic roller lifters is 6500 RPM. Currently can run to 6300 before valve float, so not much left before the lifter limits.
However I wonder if those lifter limits are based on conventional springs and the spring pressure needed to control them.
If that pressure is not at the limit for the lifters, causing bleed down I assume, then maybe that RPM limit may be higher as well?
Or the same pressure but higher RPM capability. I would assume with less valve train weight that float would occur at a later RPM. How much? I don't know either.
I know the advertised limit of my hydraulic roller lifters is 6500 RPM. Currently can run to 6300 before valve float, so not much left before the lifter limits.
However I wonder if those lifter limits are based on conventional springs and the spring pressure needed to control them.
If that pressure is not at the limit for the lifters, causing bleed down I assume, then maybe that RPM limit may be higher as well?
just not a hydraulic lifter person if your asking me only used them in a pickup truck. I would think though the quality of your lifter along with even the vicosity of your oil using would help.
I'm sure you know they make a shorter travel hydraulic roller lifter now that turns them into closer to being like a solid roller lifter but ya the valve springs like the behive have proven themselfs to improve the rpm limit of hydraulic roller cams. That's the reason they started showing up on C5 vettes like the ZO6 they generally do 7000 rpm without any problems doing it. Me personally if I had a hydraulic roller I would run a strait vicosity oil not 10W whatever then use a behive valve spring. The conical I'm going to use one big reason the high rpm of the solid flat tappet cam. A cheaper in cost behive spring should work real well with a hydraulic roller.
Last edited by Little Mouse; Feb 15, 2022 at 07:16 PM.
Basically a behive spring works like a progressive spring its top coils are lighter then as it goes into higher lift from the cam shaft the spring is getting stiffer in its pressure a conical spring is even more progressive everywhere then the behive spring. The differences in all the coil windings in the spring top to bottom are what is canceling out harmonic problems with a behive spring even more so with a conical valve spring.
Very nice you sure you can't just drop that off at one of the 15 houses I'm now maintaining any one of the garages will be fine. Yep the 337 I'm starting to build going in a 1750 lb triumph spitfire. When I'm done with it with me in the car should be total weight a little over 2400 lbs. I can't afford to do a 57 vette one of my favorites or a C2. Just my opinion but the C2 dash best looking I have ever seen in a production car, I could just about set inside a C2 all day and night and marvel at how good the dash looks even the vertical radio way cool. While your at it can you drop that yellow car off to. By the way in that pinto any chance your setting the engine back in the frame then setting closer to where the back seat used to be. Crankshaft snout double keyed on your cleavland.
I agree...the C2 dash is just about perfect.......love mine! That Spitfire will be insane also!
That coupe is a real steel '32.......nice cruiser the wife can enjoy.....but will smoke the tires for fun!
Not sure how I'm going to settle on mounting the engine. I know it will fit without messing with the firewall...but it's an early model..so engine bay is shorter than the later ones. Might move it back a little to get some room and help weight balance.
Yep..I added a second keyway on the crank with a steel hub.
Seems like DeWalt and a couple of others have them. I've also seen a peddle switch that plugs inbetween grinder and wall to vary RPM...but I haven't used one yet.
You can use HF inside outside calipers...comes in a set with a bunch of others for about $10. Then use a good digital caliper to measure them.
Pay close attention to the throat area under the seat. Don't go too big...it will ruin the flow. You need to measure that one closely. Typically intake in the 90% range of the valve to maintain a venturi effect.
Here's the aluminum I recently removed from the heads and intake I ported for my project...LOL
I agree...the C2 dash is just about perfect.......love mine! That Spitfire will be insane also!
That coupe is a real steel '32.......nice cruiser the wife can enjoy.....but will smoke the tires for fun!
Not sure how I'm going to settle on mounting the engine. I know it will fit without messing with the firewall...but it's an early model..so engine bay is shorter than the later ones. Might move it back a little to get some room and help weight balance.
Yep..I added a second keyway on the crank with a steel hub.
Spitfire only has an 83 inch wheelbase the clamshell hood tilts forward or is that the bonnet 😆 I'm going to buy a fiberglass bonnet not to lose the 60 lbs it's lighter but to cut the wheel wells move them forward along with moving the front A arms all the front suspension, and manual rack forward, I want to keep the overall body length the same don't want a goofy looking extended front end that most all do when they put a V8 in them. Weakling rear IRS that's known to withstand a wopping 135 hp will be replaced with a narrowed most likely mossier 12 bolt chevy then I'm almost sure for $2600.00 the latest redesigned tremec tkx 600 5 speed will be the trans .082 overdrive version of it, I like close as possible gear ratios with as little drop in rpm between gears as I can do.
Last edited by Little Mouse; Feb 16, 2022 at 11:49 AM.
just not a hydraulic lifter person if your asking me only used them in a pickup truck. I would think though the quality of your lifter along with even the vicosity of your oil using would help.
I'm sure you know they make a shorter travel hydraulic roller lifter now that turns them into closer to being like a solid roller lifter but ya the valve springs like the behive have proven themselfs to improve the rpm limit of hydraulic roller cams. That's the reason they started showing up on C5 vettes like the ZO6 they generally do 7000 rpm without any problems doing it. Me personally if I had a hydraulic roller I would run a strait vicosity oil not 10W whatever then use a behive valve spring. The conical I'm going to use one big reason the high rpm of the solid flat tappet cam. A cheaper in cost behive spring should work real well with a hydraulic roller.
I guess I hadn't really considered the wt of oil being used. Thinking about it that certainly could be a factor for bleed down on the hyd lifters. I'm using 0w-40 currently. 40w should do pretty well against leak back on the lifters.
Short stroke hyd rollers, wouldn't that be about the same as running the lash down a bunch to make the oil chamber in the lifter small?
I did see retro roller hyd lifters with a 7000+ rpm by Howard's. Takes a minimum of 200 on the seat and 500 over the nose to run them. That's quite a bit more than I'm running now.
I'm familiar with how behive, and now conical springs, and how they cancel out natural resonance frequencies at various RPM's and and how this enhances valve train/lifter control. That said, it's sounds like it's still going to take the high spring pressures to minimize/eliminate bounce and loft based on the weight of the lifter, valve, retainer, keeper combination. does this sound right?
If I retain a pretty heavy lifter then I'm limiting my RPM more, or required to use more spring pressure, just do to that additional wt.
For me this is just academic at this point due to the bottom end of my 350 would not survive long with 7000 RPM blasts in any case.
Not sure about the lifters that are made for higher rpm could be more then a few differences to accomplish that, different oil valving could be differences in spring inside the lifter way its made inside altogether. Why can't you turn rpm with what you have 7000 rpm should be pretty easy on sbc parts. We're me I'd get that 0 to 40 oil out of my engine with a hydraulic if you ever read up on what it takes to make oil multi viscosity you will think again about using it in anything not like its hard to run a strait viscosity in winter then run another heavier viscosity in summer. Seems less then 400 lbs on the nose for hydraulic rollers, if howards has some can withstand 500 its some form of special lifter. I have a triumph motorcycle I bought new back in 2018 the engine and trans share the same oil. Gears meshing together called gear sher is hard on the oil breaks it down quicker so winter I run strait 40 in it then change to strait 50 weight in the spring, its a motorcycle oil because of the wet clutch they use.
Last edited by Little Mouse; Feb 17, 2022 at 03:21 PM.
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.
