100 Cams & 100 posts. need help
#21
Intermediate
Et
Well when I use Summit's c.r. calculator using your specs I get 10.74 static c.r.! That's quite a difference. And what I've been trying to say is that since you have the block on the table/stand you could get very accurate volume measurements (using liquid) instead of using published specs that can be unreliable.
If you must I suggest a simple dynamic calculator to try several different cam profiles for the dynamic c.r. that you want. I found this calculator by United Engine Machine that looks to be as simple as it gets: https://www.uempistons.com/index.php...3c8dd514d00dd2
I hope the link works for you. Good luck.
If you must I suggest a simple dynamic calculator to try several different cam profiles for the dynamic c.r. that you want. I found this calculator by United Engine Machine that looks to be as simple as it gets: https://www.uempistons.com/index.php...3c8dd514d00dd2
I hope the link works for you. Good luck.
http://members.cardomain.com/cardo0 What et does this car run?
#22
Race Director
74 T-top, L-48, 4spd, A/C, narly blue. Goodwrench 350 underwent new heads (SR Torquers), Schneider solid cam and Thorley headers. Now runs a Performer Air Gap with a lars majic chokeless Qjet on top. Also Street dampner, MSD dist, 6AL and Baster II.
http://members.cardomain.com/cardo0 What et does this car run?
http://members.cardomain.com/cardo0 What et does this car run?
The following users liked this post:
Dirttracker (11-26-2017)
#24
Instructor
Thread Starter
I use alcohol with food coloring in it. If you can find 1/4" plexiglass you can make your own cover and drill a hole with a nice wide chamfer on it. I'm still using the plexiglass plate I bought decades ago and I think it was a Comp Cams kit but you can find the graduated (ml) cylinder on line. I asked the pharmacist at Target for some graduated syringes (no needle) and got a handful of 5cc for free.
I use petrol jelly to seal the plexiglass and a thick grease to seal the crivece between piston and cylinder wall. Don't expect everything to seal w/o bubbles the first try. Keep working with it until you get it where you can repeat it accurately. Clean parts should be easier to work with than used parts. Here's a link to my camaro's LT1 liquid measurements with pix: https://camaroforums.com/forum/lt1-l...mes-ccd-81437/
That HSR looks pretty bad azz and your motor is looking great to. Almost to good looking to install and run . I would hate to get that one dirty.
I think you will have alot of self satisfaction once you get it done.
I use petrol jelly to seal the plexiglass and a thick grease to seal the crivece between piston and cylinder wall. Don't expect everything to seal w/o bubbles the first try. Keep working with it until you get it where you can repeat it accurately. Clean parts should be easier to work with than used parts. Here's a link to my camaro's LT1 liquid measurements with pix: https://camaroforums.com/forum/lt1-l...mes-ccd-81437/
That HSR looks pretty bad azz and your motor is looking great to. Almost to good looking to install and run . I would hate to get that one dirty.
I think you will have alot of self satisfaction once you get it done.
Last edited by Street89vette; 11-26-2017 at 09:07 PM.
#25
An 89 isn't solid roller. Did I miss something? Looked again and didn't see "solid" listed in this thread until your post.
Here's the official link for the SR cam specs...
https://www.lingenfelter.com/PDFdown...L210035087.pdf
Here's the official link for the SR cam specs...
https://www.lingenfelter.com/PDFdown...L210035087.pdf
That is my interpretation and could be wrong.
#26
Le Mans Master
#27
Race Director
The OP may add to this but there was a company (USM) making modified HSRs several years ago. Member "Bjankuski" owns one IIRC.
At the time they started business, there was a group purchase proposed. I don't remember if anyone (else) tried/bought one, but here is a link to that thread (in case, there's discussion of the design).
https://www.corvetteforum.com/forums...m-l98-lt1.html
I also Googled "USM HSR intake images" to see if pics still exist from the defunct website....or at least from someone who's modified an HSR. Here are a couple of the images I found:
Considering the ingenuity of people willing to "make" their own intakes, the options for making an HSR fit aren't likely to be limited to one method. Having SAID that, if you "chop" the plenum and make it shallower, you'll affect "air supply" to the runners. (Lingenfelter understood this when designed the Super Ram.)
In the pics, you'll see USM (and others) cut open the bottom of the plenum (using a trace outline of the top of the base). Then they chop off the runner "extensions" (extending up from the base) at an angle. Finally, they weld the two pieces resulting in a plenum that angles downward toward the front of the intake.
With the plenum "floor" angled, you might wonder if better penetration of air is achieved in front runners. ("Ram Air" style intakes typically have more air "rammed" into the rear runners.) You also have to wonder how reversion is affected.
The HSR is considered somewhat more desired than a miniram because it's runners are closer to an LSx intake. (Yes, people recognize there's some advantage in capturing reversion -- especially if it can be done at an "ideal" tq/hp peak where power roll-off doesn't "waste" rpm limitation of the engine.) With varying runner lengths, rear cylinders will "peak" a bit lower than the fronts...but they also tend to get more air anyway. The result might not be "bad". Plus, some builders LIKE the idea of varying how individual cylinders perform.
Hopefully, this information adds inside into what the OP is attempting to accomplish.
Edit: If you have the welding skills/shop, you COULD buy a CHEAPER HSR and chop it EQUALLY front/rear. Basically, you'd have a miniram for less money. Also...I probably could have found more pictures were it not for photobucket. (We can't diss them enough!!! )
At the time they started business, there was a group purchase proposed. I don't remember if anyone (else) tried/bought one, but here is a link to that thread (in case, there's discussion of the design).
https://www.corvetteforum.com/forums...m-l98-lt1.html
I also Googled "USM HSR intake images" to see if pics still exist from the defunct website....or at least from someone who's modified an HSR. Here are a couple of the images I found:
Considering the ingenuity of people willing to "make" their own intakes, the options for making an HSR fit aren't likely to be limited to one method. Having SAID that, if you "chop" the plenum and make it shallower, you'll affect "air supply" to the runners. (Lingenfelter understood this when designed the Super Ram.)
In the pics, you'll see USM (and others) cut open the bottom of the plenum (using a trace outline of the top of the base). Then they chop off the runner "extensions" (extending up from the base) at an angle. Finally, they weld the two pieces resulting in a plenum that angles downward toward the front of the intake.
With the plenum "floor" angled, you might wonder if better penetration of air is achieved in front runners. ("Ram Air" style intakes typically have more air "rammed" into the rear runners.) You also have to wonder how reversion is affected.
The HSR is considered somewhat more desired than a miniram because it's runners are closer to an LSx intake. (Yes, people recognize there's some advantage in capturing reversion -- especially if it can be done at an "ideal" tq/hp peak where power roll-off doesn't "waste" rpm limitation of the engine.) With varying runner lengths, rear cylinders will "peak" a bit lower than the fronts...but they also tend to get more air anyway. The result might not be "bad". Plus, some builders LIKE the idea of varying how individual cylinders perform.
Hopefully, this information adds inside into what the OP is attempting to accomplish.
Edit: If you have the welding skills/shop, you COULD buy a CHEAPER HSR and chop it EQUALLY front/rear. Basically, you'd have a miniram for less money. Also...I probably could have found more pictures were it not for photobucket. (We can't diss them enough!!! )
Last edited by GREGGPENN; 11-29-2017 at 06:13 PM.
#28
Le Mans Master
Member Since: Oct 2002
Location: Las Vegas - Just stop perpetuating myths please.
Posts: 7,098
Received 373 Likes
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..... ..........
With the plenum "floor" angled, you might wonder if better penetration of air is achieved in front runners. ("Ram Air" style intakes typically have more air "rammed" into the rear runners.) You also have to wonder how reversion is affected.
(Yes, people recognize there's some advantage in capturing reversion -- especially if it can be done at an "ideal" tq/hp peak where power roll-off doesn't "waste" rpm limitation of the engine.) With varying runner lengths, rear cylinders will "peak" a bit lower than the fronts...but they also tend to get more air anyway. The result might not be "bad". Plus, some builders LIKE the idea of varying how individual cylinders perform.
Hopefully, this information adds inside into what the OP is attempting to accomplish.
With the plenum "floor" angled, you might wonder if better penetration of air is achieved in front runners. ("Ram Air" style intakes typically have more air "rammed" into the rear runners.) You also have to wonder how reversion is affected.
(Yes, people recognize there's some advantage in capturing reversion -- especially if it can be done at an "ideal" tq/hp peak where power roll-off doesn't "waste" rpm limitation of the engine.) With varying runner lengths, rear cylinders will "peak" a bit lower than the fronts...but they also tend to get more air anyway. The result might not be "bad". Plus, some builders LIKE the idea of varying how individual cylinders perform.
Hopefully, this information adds inside into what the OP is attempting to accomplish.
This mirrors my plans to convert a dual plane carburetor intake to EFI. Mostly for modest cammed street motors it should boost torque below mid-range and you can also include an EGR pad for emissions concerns. It does take an intake elbow and accurate location of the injector bosses. I obtained a converted TPI plenum already but intake elbows are available on the shelf now if desired. I think you would match a dual plane intake conversion to a street performance vehicle rather than a serious race effort. But it could be a very good substitute for a TPI motor/intake.
#29
Pro
The OP may add to this but there was a company (USM) making modified HSRs several years ago. Member "Bjankuski" owns one IIRC.
At the time they started business, there was a group purchase proposed. I don't remember if anyone (else) tried/bought one, but here is a link to that thread (in case, there's discussion of the design).
https://www.corvetteforum.com/forums...m-l98-lt1.html
I also Googled "USM HSR intake images" to see if pics still exist from the defunct website....or at least from someone who's modified an HSR. Here are a couple of the images I found:
At the time they started business, there was a group purchase proposed. I don't remember if anyone (else) tried/bought one, but here is a link to that thread (in case, there's discussion of the design).
https://www.corvetteforum.com/forums...m-l98-lt1.html
I also Googled "USM HSR intake images" to see if pics still exist from the defunct website....or at least from someone who's modified an HSR. Here are a couple of the images I found:
Just need to find it in my shed somewhere.
#30
Safety Car
I am still around playing with vettes.... albeit a C6 these days. I race most weekends at the track. I fly by in here from time to time.
I'm looking to pick-up a C4 in the coming months and building something with it.... more of a dedicated racecar than anything.
Still trying to figure out the plan though... it's complicated with the race series I am interested in right now.
#31
Safety Car
Well, the OP did say just 12.20.... which you can do with a 383 with a stock tube runners, let alone a HSR, SR or MR or whatever.
Whatever he chooses, I wish him well.
#32
Hi Aaron !!
I am still around playing with vettes.... albeit a C6 these days. I race most weekends at the track. I fly by in here from time to time.
I'm looking to pick-up a C4 in the coming months and building something with it.... more of a dedicated racecar than anything.
Still trying to figure out the plan though... it's complicated with the race series I am interested in right now.
I am still around playing with vettes.... albeit a C6 these days. I race most weekends at the track. I fly by in here from time to time.
I'm looking to pick-up a C4 in the coming months and building something with it.... more of a dedicated racecar than anything.
Still trying to figure out the plan though... it's complicated with the race series I am interested in right now.
Good to hear from you. It seems that most of us older guys from the early days have acquired newer model Vettes. What series are you intending to race with the C4?
I wound up taking my old C4 very deep 9s in the mid 2000s, and got perma-banned from my local track due to lack of safety equipment (only a hoop in the 87 vert). It is still street legal, so never intended to do a full cage.
I have a C6 that I wound up doing a bunch of work and is TT. Love that car, but never could get the times that I wanted. I recently bought a C7Z07 and have started acquiring mod parts for that.
I live overseas and only get time to play when I am in the States. I hope to end the ex-pat assignment and return home soon, so maybe a chance then.
I did give my other C4 to my oldest son (2nd son loves his Supra Turbo) and he is running that with many of my old parts (big TPIS cam, my old worked LPE heads, single plane intake, 3.45D44, ect). The "stripper" vette weighs right at 2800lbs and runs strong. He seems to like it!
Anyways, it is always good catching up with old friends on this forum. Cheers!
Aaron
#33
Safety Car
Good to hear from you. It seems that most of us older guys from the early days have acquired newer model Vettes. What series are you intending to race with the C4?
I wound up taking my old C4 very deep 9s in the mid 2000s, and got perma-banned from my local track due to lack of safety equipment (only a hoop in the 87 vert). It is still street legal, so never intended to do a full cage.
I have a C6 that I wound up doing a bunch of work and is TT. Love that car, but never could get the times that I wanted. I recently bought a C7Z07 and have started acquiring mod parts for that.
I live overseas and only get time to play when I am in the States. I hope to end the ex-pat assignment and return home soon, so maybe a chance then.
I did give my other C4 to my oldest son (2nd son loves his Supra Turbo) and he is running that with many of my old parts (big TPIS cam, my old worked LPE heads, single plane intake, 3.45D44, ect). The "stripper" vette weighs right at 2800lbs and runs strong. He seems to like it!
Anyways, it is always good catching up with old friends on this forum. Cheers!
Aaron
I wound up taking my old C4 very deep 9s in the mid 2000s, and got perma-banned from my local track due to lack of safety equipment (only a hoop in the 87 vert). It is still street legal, so never intended to do a full cage.
I have a C6 that I wound up doing a bunch of work and is TT. Love that car, but never could get the times that I wanted. I recently bought a C7Z07 and have started acquiring mod parts for that.
I live overseas and only get time to play when I am in the States. I hope to end the ex-pat assignment and return home soon, so maybe a chance then.
I did give my other C4 to my oldest son (2nd son loves his Supra Turbo) and he is running that with many of my old parts (big TPIS cam, my old worked LPE heads, single plane intake, 3.45D44, ect). The "stripper" vette weighs right at 2800lbs and runs strong. He seems to like it!
Anyways, it is always good catching up with old friends on this forum. Cheers!
Aaron
I bought a C6 Z06 years back.... intended to leave it stock, but didn't work out. Now a 442 LS7 with an Auto conversion. Run's easy 9 second times on motor, but I mostly race 1/8th where it runs low 6's. Been a fun car... I race some Prep and No-Prep events mostly in the index classes.
What I am considering for a C4 is a True Street project... or Outlaw True Street. I am already involved with them.... most of my friends race in one other other. Problem is, the classes are evolving fast and a lot of talk about rule changes... not sure where it is going. 2 years ago, if you had a 5.50 car you were a player..... now if you have a 5.50 car, there are fist fights in the lanes trying to get next to you, cuz you're the duck.
As of this year, the fastest guys are running 4.80's at over 150 mph. This is just in 2 years of evolution.... imagine it in another year or two. So I don't know yet. I'd at least like the class to slow down so I know a number I'd have to run to be competitive. We'll see.
Hope you can get back to the State permanently soon.... there is racing to be done.
#35
Instructor
Thread Starter
Last edited by Street89vette; 12-04-2017 at 03:27 PM.
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MatthewMiller (12-04-2017)
#36
Le Mans Master
Now I have some evening reading to do!
#37
Race Director
Yeah...the link closing tag got buried in the IMG tag. Matt beat me to the fix.
Street89Vette: I'll be curious what you use for a distributor
Street89Vette: I'll be curious what you use for a distributor
Last edited by GREGGPENN; 12-04-2017 at 05:24 PM.