PLEASE HELP wrong pistons knock & pinging
05-15-2016, 08:42 AM
#21
5th Gear Member
Join Date: Mar 2008
Location: wisconsin
Posts: 2,260
here is a link to modular fords and a write up by a member that pretty completely covers the compression ratio vs boost debate. http://www.modularfords.com/threads/...boost-pressure
read through it and then you will understand how a high compression low boost engine, is less efficient and will without doubt leave power at the table when compared to a low compression high boost engine.
read through it and then you will understand how a high compression low boost engine, is less efficient and will without doubt leave power at the table when compared to a low compression high boost engine.
05-15-2016, 12:13 PM
#22
5th Gear Member
Join Date: May 2009
Location: kentucky
Posts: 2,241
First off, oxfordgt, shut up. You provided a decent option in the beginning but as usual, you start you're bs and lieing. Stop being a troll for everyone's sake!
Jwog, you provided good "rule of thumb" information but some of it was misleading. There are plenty of high compression, boosted engines out there. Granted that most are full blown race engines and depending on what ppl call high compression.
OP, there are a few options you can take here depending on a few variables.
1) you could reassemble your engine with the correct pistons and go on with your plans.
2) the Trickflow heads wont lower your compression since the largest, I can find, were the 44cc heads. These heads do use a new valve placement that help flow and if you don't have piston notches, you can run larger cams than pi heads.
3) if you have piston notches, you could run cams large enough to bleed off dymanic compression so pump gas can be run. Your stock cams and 12.5 compression is causing detnation like crazy!
Jwog, you provided good "rule of thumb" information but some of it was misleading. There are plenty of high compression, boosted engines out there. Granted that most are full blown race engines and depending on what ppl call high compression.
OP, there are a few options you can take here depending on a few variables.
1) you could reassemble your engine with the correct pistons and go on with your plans.
2) the Trickflow heads wont lower your compression since the largest, I can find, were the 44cc heads. These heads do use a new valve placement that help flow and if you don't have piston notches, you can run larger cams than pi heads.
3) if you have piston notches, you could run cams large enough to bleed off dymanic compression so pump gas can be run. Your stock cams and 12.5 compression is causing detnation like crazy!
05-15-2016, 01:21 PM
#23
5th Gear Member
Join Date: Mar 2008
Location: wisconsin
Posts: 2,260
the information was not misleading,the OP is building a street engine, and not a high revving purpose built track engine. the OP knows that, i know that, and anybody who responds to his post should know that. can a high compression boosted engine be built?.......yes. is it a good idea for a non track car application?.....not ever. results prove that as a fact. i try to answer questions without using hypothetical situations.
05-15-2016, 03:28 PM
#24
5th Gear Member
Join Date: May 2009
Location: kentucky
Posts: 2,241
Like I mentioned before, depending on what people believe is high static compression. If the op thinks 10:1 compression is high in a modular then the information can be misleading vs thinking 11.5:1 is high compression which youre information, and yes I read it, is very right.
There are exceptions out there, not naming the person who hasn't been on here in quite a while, who In conversation said to me that a nice street motor to him would be 11:1 compression, small cams to help to "bleed" off damanic compression, and about 6-8 psi on a positive displacement blower on pump gas. This person did have the credentials about cars in general and modular. Personally, I would choose 10:1, a set of baby cams, and 10 psi positive displacement blower on pump gas but eh.
I'm not giving you crap for the information you provided, its very good. I'm just trying to make sure nothing gets twisted around and bad decisions get made.
There are exceptions out there, not naming the person who hasn't been on here in quite a while, who In conversation said to me that a nice street motor to him would be 11:1 compression, small cams to help to "bleed" off damanic compression, and about 6-8 psi on a positive displacement blower on pump gas. This person did have the credentials about cars in general and modular. Personally, I would choose 10:1, a set of baby cams, and 10 psi positive displacement blower on pump gas but eh.
I'm not giving you crap for the information you provided, its very good. I'm just trying to make sure nothing gets twisted around and bad decisions get made.
05-15-2016, 03:40 PM
#26
6th Gear Member
Join Date: May 2006
Location: Ohio
Posts: 6,448
First off, oxfordgt, shut up. You provided a decent option in the beginning but as usual, you start you're bs and lieing. Stop being a troll for everyone's sake!
Jwog, you provided good "rule of thumb" information but some of it was misleading. There are plenty of high compression, boosted engines out there. Granted that most are full blown race engines and depending on what ppl call high compression.
OP, there are a few options you can take here depending on a few variables.
1) you could reassemble your engine with the correct pistons and go on with your plans.
2) the Trickflow heads wont lower your compression since the largest, I can find, were the 44cc heads. These heads do use a new valve placement that help flow and if you don't have piston notches, you can run larger cams than pi heads.
3) if you have piston notches, you could run cams large enough to bleed off dymanic compression so pump gas can be run. Your stock cams and 12.5 compression is causing detnation like crazy!
Jwog, you provided good "rule of thumb" information but some of it was misleading. There are plenty of high compression, boosted engines out there. Granted that most are full blown race engines and depending on what ppl call high compression.
OP, there are a few options you can take here depending on a few variables.
1) you could reassemble your engine with the correct pistons and go on with your plans.
2) the Trickflow heads wont lower your compression since the largest, I can find, were the 44cc heads. These heads do use a new valve placement that help flow and if you don't have piston notches, you can run larger cams than pi heads.
3) if you have piston notches, you could run cams large enough to bleed off dymanic compression so pump gas can be run. Your stock cams and 12.5 compression is causing detnation like crazy!
05-15-2016, 04:07 PM
#27
Thread Starter
Join Date: Aug 2015
Location: California
Posts: 20
Its a daily driver not track car. I will correct the pistons. I dont want to do race fuel or change heads. Supercharger will come after piston correction. What do you think about temporarily using octane booster from OReilly or Autozone??
05-15-2016, 04:10 PM
#28
Thread Starter
Join Date: Aug 2015
Location: California
Posts: 20
you mean that video that showed power numbers on a screen with no actual graph of hp/tq vs rpm? for all we know your NA engine makes power from 6-9k rpm, completely useless on the street, thats assuming that you arent making chit up like all the other times. supercharged junk? lmao its always like an idiot to try and tear down things he doesnt understand
05-15-2016, 04:11 PM
#29
Thread Starter
Join Date: Aug 2015
Location: California
Posts: 20
Its a daily driver not track car. I will correct the pistons. I dont want to do race fuel or change heads. Supercharger will come after piston correction. What do you think about temporarily using octane booster from OReilly or Autozone??
05-15-2016, 08:12 PM
#30
5th Gear Member
Join Date: Mar 2008
Location: wisconsin
Posts: 2,260
"no need to lie"? yet you still manage to lie and spout bull$hit misinformation at every turn
Last edited by jwog666; 05-15-2016 at 08:14 PM.
