viperhauck
Member
Who are the best pipes to a viper with 780 kit.
mopar1rules
Active member
Probably SLP's.
viperhauck
Member
I have hauck (cpr) now and was a little disapointed when I run it in the dyno last week. It only make 148hp. I thougt it would make 155-160.
well, something is not right, either its too low of compression, porting,or something is not up to par. The CPR pipes are the quickest pipes,meaningthey build the hp the quickest and are a darn good pipe. They are my choice of viper pipe for drag racing,or lake racing. the SLP is the quiestest pipe set,still a decent performer but the CPR has the most aggressive design.
Do a couple checks and post, maybe can help you get it up to par,should definitely be in the 160 range for hp.
what head,heads?
cranking compression?
squish clearance?
Did you buy the topend originally or get it used?
tell me some more information about it,carbs,jetting,engine specs,and we can go from there.
Do a couple checks and post, maybe can help you get it up to par,should definitely be in the 160 range for hp.
what head,heads?
cranking compression?
squish clearance?
Did you buy the topend originally or get it used?
tell me some more information about it,carbs,jetting,engine specs,and we can go from there.
viperhauck
Member
Hauck 780 kit as it come from them. Brand new, just run like 400km (240 miles) dont know the compression or squish. The cylinders have been ported little little extra by I guy in sweden who have been race and work with bender. carbs bored 35.5mm, modifed airbox for more air. v-force. We lean the jetting so we have 0.63 bsfc and 1230 F exhaust temp. It make 147.6 9050rpm and over 146 from 8800 to 9200 rpm
I have a used venom head with 780 domes, Should I try it??
I have a used venom head with 780 domes, Should I try it??
viperhauck
Member
This is the head I have. Bought it from a TY member
viperhauck
Member
In dyno it was this head, modified stock head by hauck
ahh ok, so its a hauck 780 with cpr pipes then.
1.) first thing to check is the squish, simply take a peice of lead solder about .080" diameter and make a "L" out of it, then insert thru the sparkplug hole, make sure you can "feel" the smooth side of the bore. Always go from right or left side of the bore not the front or back to keep the piston from rocking and giving you a false reading. Now holding the solder in the cylinder take your other hand and rotoate the primary clutch, this will "squish' the solder between the head and cylinder at TDC. remove solder and check thickness with calipers.
If this is a Hauck engine my guess youll see at least .070" squish which is way too much.
do this first and post back. also if you have a compression guage that screws into the sparkplug hole check that for me, pull it about 10 times and give me the reading.
1.) first thing to check is the squish, simply take a peice of lead solder about .080" diameter and make a "L" out of it, then insert thru the sparkplug hole, make sure you can "feel" the smooth side of the bore. Always go from right or left side of the bore not the front or back to keep the piston from rocking and giving you a false reading. Now holding the solder in the cylinder take your other hand and rotoate the primary clutch, this will "squish' the solder between the head and cylinder at TDC. remove solder and check thickness with calipers.
If this is a Hauck engine my guess youll see at least .070" squish which is way too much.
do this first and post back. also if you have a compression guage that screws into the sparkplug hole check that for me, pull it about 10 times and give me the reading.
viperhauck
Member
How low squish can a go? And when I do the compression test should I have throttle closed or WOT?
ridergonwild5692
Member
you have to hold the throttle wide open to get a accorate reading.
viperhauck, lets check what ya got first.
it really doesnt make all that much differance on the throttle, as long as you pull it over about 10 times, I will know whats up with the squish check and the compression reading, even if your guage would be 10lbs low, its gonna tell me a story those 2 peices of information.
it really doesnt make all that much differance on the throttle, as long as you pull it over about 10 times, I will know whats up with the squish check and the compression reading, even if your guage would be 10lbs low, its gonna tell me a story those 2 peices of information.
viperhauck
Member
Ok, I´m away at work now. I check that out next weekend when I come home.
viperhauck
Member
Now I have check mrviper:
128-130 psi
Squish .0748 or 1.9mm if I have translate it right.
128-130 psi
Squish .0748 or 1.9mm if I have translate it right.
Last edited:
Mac
Member
Squish will need to be adjusted to .050 -.054 using premium fuel. Compression should come up to roughly 145-148. If you can run bored or larger carbs you will increase power. I run CPR and have no complaints.
viperhauck
Member
I alredy have bored carbs
viperhauck
Member
I also check the venom head. Without headgasket it was 1.3mm = 0.0512
"oem" head without headgasket 1.1mm = 0.0433
"oem" head without headgasket 1.1mm = 0.0433
Last edited:
take a pic of the bottom side of both heads for me.
the squish is way too big. I guessed at .070" before and figured this would be a issue. After you post a pic, I will tell ya which one to reinstall and youll need to peel the headgasket, and likely only install 1 or 2 layers of it. this will reduce the squish clearance and increase the compression ratio, which will in turn boost up the power and response quite a bit.
what octane fuel do you run?
the squish is way too big. I guessed at .070" before and figured this would be a issue. After you post a pic, I will tell ya which one to reinstall and youll need to peel the headgasket, and likely only install 1 or 2 layers of it. this will reduce the squish clearance and increase the compression ratio, which will in turn boost up the power and response quite a bit.
what octane fuel do you run?
viperhauck
Member
I run premium, the best pumpgas
viperhauck
Member
Venom head has 25.3cc domes
youll have far better and more even cooling with the aftermarket ones. the stock head has a design flaw in that it creates an eddy in the coolant flow for the mag cylinder which makes it run hotter.
few questions:
1.) did you cc the hauck head?
2.) what octane is your premium fuel there?
3.) the radius on the hauck head loks better then the radius on the venom heads,however you could smooth them out pretty easily, the radius in which I refer to is the one from the center dome to the squish angle, this needs to be nice and smooth not a sharp corner. its hard to tell from just a pic but the recut stock head looks to have a smoother radius, however the cooling benfits of the venom far outweigh any of this. Its just something I notice that catch's my eye.
few questions:
1.) did you cc the hauck head?
2.) what octane is your premium fuel there?
3.) the radius on the hauck head loks better then the radius on the venom heads,however you could smooth them out pretty easily, the radius in which I refer to is the one from the center dome to the squish angle, this needs to be nice and smooth not a sharp corner. its hard to tell from just a pic but the recut stock head looks to have a smoother radius, however the cooling benfits of the venom far outweigh any of this. Its just something I notice that catch's my eye.