Low power on a 427
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Teching In
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Ok, got the specs on the motor thanks to Jason at Katech.
12.3cc dish on pistons, piston .005" above deck. So with a bore or 4.125, stroke of 4", headgasket thickness measured at .044" compressed I'm assuming .042"? , Comb chamber 65cc, I come up with a static compression of 11.3:1
Oh and I can't use an LS7 head because the valve reliefs are for 2.100" max intake valve.
So now I'm looking at L92 data and other heads for the bigger bore.
12.3cc dish on pistons, piston .005" above deck. So with a bore or 4.125, stroke of 4", headgasket thickness measured at .044" compressed I'm assuming .042"? , Comb chamber 65cc, I come up with a static compression of 11.3:1
Oh and I can't use an LS7 head because the valve reliefs are for 2.100" max intake valve.
So now I'm looking at L92 data and other heads for the bigger bore.
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Made up my mind and went with some TF 235's from TEA. I'll have them in roughly 10 days and just put the small bore AFR's for sale (looks like I can't sell until 50 posts?).
I've read good things on both the AFR's and TF so it was a tough choice.
I've read good things on both the AFR's and TF so it was a tough choice.
It should be a monster with the 235's. Make sure the fast is ported well and matching up to the heads. You need to run the data on the cam profile and get an idea of the dynamic compression of the engine. A good range for 93 octane would be 8.5-9.0 so timing advance is still strong. There might be a better stick for your needs. The TF's need a roller rocker due to a geometry issue, but I'm sure TEA let you know that. If that doesn't get you nocking on 550whp's door I don't know what to tell ya(depending on cam of course).
I assume the gaskets are Cometic's? I didn't think the oem gaskets were that thin, but I'm not use to 427 stuff damnit. Lots of valvetrain stuff to measure on these so I'd recomend some searching for proper setup of pushrods, lifter preload, rocker shim and pattern, etc. Not like you wouldn't know all of this, but just in case.
I hope you keep working on some ls1 stuff as I'd mutch rather come back to AMS for dyno time rather than some of the other impersonal shops.
Ed
I assume the gaskets are Cometic's? I didn't think the oem gaskets were that thin, but I'm not use to 427 stuff damnit. Lots of valvetrain stuff to measure on these so I'd recomend some searching for proper setup of pushrods, lifter preload, rocker shim and pattern, etc. Not like you wouldn't know all of this, but just in case.
I hope you keep working on some ls1 stuff as I'd mutch rather come back to AMS for dyno time rather than some of the other impersonal shops.
Ed
I highly doubt heads will be worth 80 rwhp in this case. On paper, the one in the car should be making 530 at least.
Did you measure the cam yet? If its a comp grind there should be some numbers on the back of it that will tell you some info.
Louis
PS- Mill them a little more
Did you measure the cam yet? If its a comp grind there should be some numbers on the back of it that will tell you some info.
Louis
PS- Mill them a little more
Louis, I'm just stating what a well running package would put down give or take a few. I realize something is holding the old setup back so if the old AFR's are in good shape I'd think the problem would be cam related. Unless something else is hiding in the mix. If he does the TFS heads everything up top will change (pushrods, rockers, heads, etc) so if that doesn't fix it what would? Let us know if you get the cam out Martin. As Louis said if it's a comp cam it will have two grind numbers on it which you can look up on comps website. It might also state LSA and ICL.
Ok, got the specs on the motor thanks to Jason at Katech.
12.3cc dish on pistons, piston .005" above deck. So with a bore or 4.125, stroke of 4", headgasket thickness measured at .044" compressed I'm assuming .042"? , Comb chamber 65cc, I come up with a static compression of 11.3:1
Oh and I can't use an LS7 head because the valve reliefs are for 2.100" max intake valve.
So now I'm looking at L92 data and other heads for the bigger bore.
12.3cc dish on pistons, piston .005" above deck. So with a bore or 4.125, stroke of 4", headgasket thickness measured at .044" compressed I'm assuming .042"? , Comb chamber 65cc, I come up with a static compression of 11.3:1
Oh and I can't use an LS7 head because the valve reliefs are for 2.100" max intake valve.
So now I'm looking at L92 data and other heads for the bigger bore.
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Teching In
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Pulled the Cam, the cams was installed straight up. It's a Flowtech # I9015-060
I put it on my cam analyzer and this is what I got. I have to double check my geometry but I'm assuming it's right until I finalize everything Rocker Arm Ratio: 1.7 Follower Diameter: .842, Follower roller diameter: .75" Cam base circle: 1.423" Can anyone verify these?
Intake: (I assumed a 110 ICL)
Valve Lift: .621
Duration @ .050" : 242deg
valve events @ .050" IVO: 10.7 BTDC IVC: 51.4 ABDC
Exhaust centerline 113
Valve Lift: .612
Duration @ .050" : 245.7 deg
valve events @ .050" EVO: 55 BBDC EVC: 10.7 ATDC
Overlap @ .50" 21.5 deg
LSA: 111.5
Again I'll check my geometry
I put it on my cam analyzer and this is what I got. I have to double check my geometry but I'm assuming it's right until I finalize everything Rocker Arm Ratio: 1.7 Follower Diameter: .842, Follower roller diameter: .75" Cam base circle: 1.423" Can anyone verify these?
Intake: (I assumed a 110 ICL)
Valve Lift: .621
Duration @ .050" : 242deg
valve events @ .050" IVO: 10.7 BTDC IVC: 51.4 ABDC
Exhaust centerline 113
Valve Lift: .612
Duration @ .050" : 245.7 deg
valve events @ .050" EVO: 55 BBDC EVC: 10.7 ATDC
Overlap @ .50" 21.5 deg
LSA: 111.5
Again I'll check my geometry
Just from a quick look nothing seems out of whack here. Nothing that would hove held the engine back 80 hp at least. Have to see what Louis thinks about the valve events overall. Thats a large cam, but not oversized for a 427. I wouldn't want anything bigger in a driver even though it's a 427.
The 1.7 ratio is right for the rockers and the base circle will be smaller on the aftermarket cams due to lift requirments which will also require longer pushrods than stock unless the block/heads were surfaced and/or a thinner headgasket is used.. Not sure about the lifter diameter/roller diameter.
The 1.7 ratio is right for the rockers and the base circle will be smaller on the aftermarket cams due to lift requirments which will also require longer pushrods than stock unless the block/heads were surfaced and/or a thinner headgasket is used.. Not sure about the lifter diameter/roller diameter.
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Going down to 2.10 in that head would probably get the seat throat smaller than the intake bowl already is, and you dont put material back in the bowl. TFS 235 should really shine, I dont know what bore they are setup for, but should do better than any head setup for 3.90".
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Well here is an update on the car. This year has been super busy with an engine competitions we're doing with Castrol and numerous other competitions. I wound up getting a set of CNC ported Dart heads from Joey Mendelis and a cam from Brett Bauer. Sad news about Joey passing away, I think my set of heads was one of the last set he did. I had some water get into one bore so I just pulled the block out, took it all apart and honed it. Thankfully it cleaned up with just a slight hone on that one bore. Now I'm putting it all back together, putting heads on it and checking everything over. I hope to get it back in the car in the next two weeks.
I also found some serious hack wiring in the car that I've fixed since then, go AZPS!
Also fixing other random stuff like the front sway bar installed upside down, oil cooler zip tied to the cross member, ect. I love fixing stuff after other shops!
I'm still trying to sell those AFR heads I have, I'll take $1700 for the heads or $1950 with the cam.
I also found some serious hack wiring in the car that I've fixed since then, go AZPS!
Also fixing other random stuff like the front sway bar installed upside down, oil cooler zip tied to the cross member, ect. I love fixing stuff after other shops!
I'm still trying to sell those AFR heads I have, I'll take $1700 for the heads or $1950 with the cam.
Well here is an update on the car. This year has been super busy with an engine competitions we're doing with Castrol and numerous other competitions. I wound up getting a set of CNC ported Dart heads from Joey Mendelis and a cam from Brett Bauer. Sad news about Joey passing away, I think my set of heads was one of the last set he did. I had some water get into one bore so I just pulled the block out, took it all apart and honed it. Thankfully it cleaned up with just a slight hone on that one bore. Now I'm putting it all back together, putting heads on it and checking everything over. I hope to get it back in the car in the next two weeks.
I also found some serious hack wiring in the car that I've fixed since then, go AZPS!
Also fixing other random stuff like the front sway bar installed upside down, oil cooler zip tied to the cross member, ect. I love fixing stuff after other shops!
I'm still trying to sell those AFR heads I have, I'll take $1700 for the heads or $1950 with the cam.
I also found some serious hack wiring in the car that I've fixed since then, go AZPS!
Also fixing other random stuff like the front sway bar installed upside down, oil cooler zip tied to the cross member, ect. I love fixing stuff after other shops!
I'm still trying to sell those AFR heads I have, I'll take $1700 for the heads or $1950 with the cam.
I have a set of Joey prepped heads myself. They are great. You will love yours and Bret is the MAN when it comes to cams. Yours will have great power and the driveability will be phenomenal...
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Update!
Well there was a lot of things wrong with the engine and car. Here is a list off the top of my head besides the things I found previously. I had few of the guys here work on this thing to get it running. Even though we don't normally work on these cars it just takes common sense and experienced mechanics to figure out it.
1. Cam bearings scored and showing heavy wear
2. Timing chain worn, way loose & missing guides
3. Electrical & wiring was way screwed, the car would go into limp mode in the rain, after washing, etc (previous owner told me), found that problem and fixed it. Knock sensors wired wrong.
4. A ton of other hacked together stuff that really didn't effect performance but sucked none the less - Zip tied oil cooler hanging on for dear life, front sway bar installed upside down, horrible in-car and under hood wiring.
Good new is everything is fixed and the car is finally running, bad news is it's Chicago and we had 4" of snow yesterday. I'll try to run it on the dyno for a while and do part throttle tuning to put at least a few miles on the motor before changing the oil (block was honed and I re-ringed it) and doing WOT tuning.
I'm really hoping to break 500whp with the combo. Previous was in the mid 460's with all the problems and wrong components so we'll see.
Well there was a lot of things wrong with the engine and car. Here is a list off the top of my head besides the things I found previously. I had few of the guys here work on this thing to get it running. Even though we don't normally work on these cars it just takes common sense and experienced mechanics to figure out it.
1. Cam bearings scored and showing heavy wear
2. Timing chain worn, way loose & missing guides
3. Electrical & wiring was way screwed, the car would go into limp mode in the rain, after washing, etc (previous owner told me), found that problem and fixed it. Knock sensors wired wrong.
4. A ton of other hacked together stuff that really didn't effect performance but sucked none the less - Zip tied oil cooler hanging on for dear life, front sway bar installed upside down, horrible in-car and under hood wiring.
Good new is everything is fixed and the car is finally running, bad news is it's Chicago and we had 4" of snow yesterday. I'll try to run it on the dyno for a while and do part throttle tuning to put at least a few miles on the motor before changing the oil (block was honed and I re-ringed it) and doing WOT tuning.
I'm really hoping to break 500whp with the combo. Previous was in the mid 460's with all the problems and wrong components so we'll see.
good to hear you are getting it sorted out
did Ivan find the cam sensor wiring after calling me last week? sounds as if this was another area of wiring that was hacked out
hope to see some #'s from the car soon
BTW: The wife loves the STI after the tune. THANKS
did Ivan find the cam sensor wiring after calling me last week? sounds as if this was another area of wiring that was hacked out
hope to see some #'s from the car soon
BTW: The wife loves the STI after the tune. THANKS
Wow, glad to hear your problems are fixed.
I've seen and heard on the Cadillac forum this car was the unicorn of all V's...sounds like it was hacked up something fierce before you got it. Sorry to hear about the issues but it looks like you'll have one hell of a car when you get it sorted out and back on the road.
Had my 100% stock V out yesterday driving home in that storm and they actually are really good in the snow believe it or not.
I've seen and heard on the Cadillac forum this car was the unicorn of all V's...sounds like it was hacked up something fierce before you got it. Sorry to hear about the issues but it looks like you'll have one hell of a car when you get it sorted out and back on the road.
Had my 100% stock V out yesterday driving home in that storm and they actually are really good in the snow believe it or not.
Last edited by Racin96ss; Dec 18, 2008 at 03:17 PM.
Any idea what the flow numbers on the heads are and the size of the cam? I hope it runs well for you Martin. If you keep the car you might get addicted to the torque of the bigger cube engines
