What RPM? I think dialing the fuel mixture in should bring it up. Plus the tech only wnt to 6300rpms even though it still had more power to go. I think I had more power with the -6/-16* cam timing. Cant really say if it would have much of an advantage because torque is less. The old cam timing was slower at start but rapped out quick at the end of the RPM range. I dunno, but I feel I should have little ways to go. He told me that it definatly had more power to go but didn't want to risk the lean mixture at that point.
He based is Hp rating at the crank at a 22% lose for front wheel drive cars.
So far I havent made any adjustments since I put the new computer in other than take the mini-afc off....after the dyno. It was set to lean out by 4%. I left the afc on even after i swapped out the computer. Should have tried that before i ran it at the dyno.
Oh, to answer your question.....I am running the 13* exhaust retard on the cam timming.
Lol. That's also what I was thinking Steven. I need to get mine on a dyno after the intake. Bob didn't you have the timing 180 degree out on one set of cams before?
[This message has been edited by Emc209i (edited 06-08-2008).]
Yes I did. That is why I may go back to the -6/-16* timming again but set the banks correctly. I was just reading the thread on another forum that sponsored the event and everyone is saying the dyno was averageing 8-10% lower than other locations. I have to assume they are telling the truth because some of these guys were in the Texas Dyno Jam (in Modified Mag in march) and there numbers are lower on this run. Even at 8% off that would put the HP around 239 HP at the wheels. Wishful thinking? Maybe but I cant imagine all this work would only yield 25Hp gain over stock....but if mixture is off who knows. I still have the tunning to do. We will se what happens. I may check with another Dyno shop to see what turns out.
Ricky (gray tt viper ) was there too. He is rated at 1700hpbut they couldn't read that high.
Several people are reading these numbers to the wheels with the new intake. That's not that big of a surprise. You need to find out why you're torque is so low.
If the 13* retard is killing torque like your car, that would certainly explain the up top "pull" feeling the retard is supposed to give. Steven I'm starting to think you were right all along.
Several people are reading these numbers to the wheels with the new intake. That's not that big of a surprise. You need to find out why you're torque is so low.
If the 13* retard is killing torque like your car, that would certainly explain the up top "pull" feeling the retard is supposed to give. Steven I'm starting to think you were right all along.
What is Steven right about? Just trying to clarify which statement.
All I know is -13* exhaust has a lower end compaired to the -6/-16* but the -6/-16* has more power on the top end. However the -13* seems to have a more wider useable power band. But ofcoarse I have to try it with the banks opposed to each other instead at the same time.
I know the large intake reduces torque because velocity is slower at lower RPM's. That's why my old intake had better torque but less HP. But my driving is more high way and that is where the HP comes in more than torque because I'm in the Higher RPM range anyway.
Any ideas are welcome..I'm just trying to figure out the best combination. I knew going to -13* retard would hurt my Hp compaired to -6/-16 setting but for lowend torque is needed. So I'm actually contradicting what I want to do. I know it sounds dumb but I'm looking for a balance to go with.
[This message has been edited by procarnut (edited 06-08-2008).]
I'm curious as to what numbers you'd make with stock belt timing- On a dyno. Very few people have ever dyno'd cam adjustments. The ones who have, have all proven more overlap destroys torque. I am a big fan of the open intake, the motor is designed to pull lots of air. I just think the timing adjustments are all just essentially biasing power towards top end, rather than peaking TQ and HP numbers. I think you can get that power number out of your motor, along with a better torque number, with less cam overlap.
I know it is a comprimise. I really like the high way response. It definately pulls away quick going down the highway. Plus it sticks well with the vettes. I'm a corvette nut also.
I have a program Dyno 2000 to play with so I'll exsperiment with it.
I actually expected the torque to suffer since the intake plenum is a 4" pipe and a 3" throttle body. But according to the link, torque looks about the same as stock. But HP is substantial. Remember I have the fuel mixture to adjust with and that alone will bring the numbers up quite a bit. Hofefully I can get a bettter adjustment with the dyno sheet to refere to...
It that is the case...217.9 + 10% = 239.60HP at the wheels + 15 = 254.6 at crank or +25 (18" wheels and 12.5" brakes) = 264.60 at the crank. Some of the members there were complaining it was running conservative. Hey If it didn't, it would be harder to make more performance sales. But it might not be intentional. They seem like good guys and willing to help too. But anyhow I was wanting something accurate to compair with.
Either way I have stuff to do and I will be looking into another dyno later.
I have a problem. I'm lifting the engine/cradle into my 1988GT for the first time and something is out of wack. This is a picture I lifted from Steven Snyder's build thread (Thanks Steven!).
The green arrow shows how far my engine is shifted rearward. I have the two forward cradle bolts installed and was rotating the rear up for the rear two bolts. The engine just stopped coming up and I found the rear cam cog cover was jammed under the dogbone brace.
Any suggestions?
Neil
------------------ 1988 GT, 5-speed, white, beechwood leather, 3.4 DOHC 6-speed installation in process. Really. I am working on it.
[This message has been edited by sspeedstreet (edited 06-09-2008).]
Lots of people have variation. That end of the motor pivots on mount 01 (in the illustration below), unless you add a fourth mount (04- highly recommended). The tilt on mount 01 is determined by the transmission mounts (02 and 03).
Steven used Dodge mounts with his motor, which also lowers the entire motor about an inch. You could try using a smaller mount on 02 and a larger on 03, to cause the motor to tilt towards the firewall. Or you can trim the dogbone mount back some.
I moved my dogbone mounting point all together, which is why I didn't have to worry about it. But if you move the dogbone, it is essential to add mount 04! I found that out the hard way.
I have a problem. I'm lifting the engine/cradle into my 1988GT for the first time and something is out of wack. This is a picture I lifted from Steven Snyder's build thread (Thanks Steven!).
The green arrow shows how far my engine is shifted rearward. I have the two forward cradle bolts installed and was rotating the rear up for the rear two bolts. The engine just stopped coming up and I found the rear cam cog cover was jammed under the dogbone brace.
Any suggestions?
Neil
As shown in the other pics in my build thread, I trimmed the dogbone brace.
In fact in the end I took that whole bracket off and did something else for the dog bone, just never liked using the ps mounting casting, looked too likely to fail to me (although I know many have used it with no problems).
Thanks for the input. I think you're right on with your diagram, Emc209i. I quit working on it last night in temporary defeat. This morning I got back under the car and found that the gel mount was allowing the motor to rotate rearward. So, back at it after work.
I don't know how I missed seeing people had trimmed the dogbone brace. I thought I'd read every scrap about the swap.
I'm curious as to what numbers you'd make with stock belt timing- On a dyno. Very few people have ever dyno'd cam adjustments. The ones who have, have all proven more overlap destroys torque. I am a big fan of the open intake, the motor is designed to pull lots of air. I just think the timing adjustments are all just essentially biasing power towards top end, rather than peaking TQ and HP numbers. I think you can get that power number out of your motor, along with a better torque number, with less cam overlap.
Well everyone knows more overlap kills vacuum too. Thus that is why most racing cams have a higher idle min. than street cams. Like most cam dynamics, Power bands can move up or down the RPM curve based on early or late timming. I've calculated the power band to peak at about 7200 RPM's which this dyno didn't show since the tech stopped at 6300 RPMs. Which he did me a favor by not letting it lean out. Which is another issue i will correct. As mentioned in the link above once you shift from 1st to 2nd, RPM is dropping from 7K to 5K so that is the power range I'm trying to reach.
Isn't Steven running -13* exhaust timming too? If I go back to -6/-16 the power band will be higher with less overlap but overall torque will suffer more because the powerband will be peaked higher up. Anyway I'll see what happens.
As far as the intake goes, I had alot more torque with the old intake (2.25 ID) but was more restrictive once RPM was cranked up. Now I'm running a 4" OD plenum (pipe or tank) and I have better flow at higher RPM. So that is where the intake is tuned for flow. So naturally a smaller plenum will produce more valocity at lower RPMs thus more torque. But for me this is playing around and having fun.
Originally posted by procarnut: Isn't Steven running -13* exhaust timming too? If I go back to -6/-16 the power band will be higher with less overlap but overall torque will suffer more because the powerband will be peaked higher up. Anyway I'll see what happens.
No I switched back to stock because I didn't like 13* when driving up in the canyons.. there is little usable torque. With a very short final drive and a close ratio box, it might be worth it go to with the tighter, peakier powerband... though it would have to be more like Michael Smith's car than like what is shown in your dyno graph. For some reason you're making only the same peak HP as me, and much less torque.. you're carrying your torque to higher RPMs but making much less of it overall. It's got to be the cam timing. Michael Smith's car was tuned similarly but he was carrying his torque so high he was making 240 whp... but I've driven the car, and its barely driveable.
More usable power. My (now) personal opinion: I believe the power band shift isn't beneficial for street use. Why? Only the power band shifts. Overlap has never proven to provide more power. I don't find this beneficial considering the massive torque loss resultant of overlap.
Results thus far: my car feels just as strong as before, even at high rpm's. The difference; it just pulls harder below 3000 rpms, the above power isn't as emphasized as before because the bottom end follows suite. The car will of course breath better with the addition of the new intake. In all cases, short runner intakes increase torque as well on the LQ1- there is no trade off when only intake parameters are improved. I plan on retaining stock timing after the upgrade. Keep in mind, a month ago, I would have never agreed to the above. All of this information is basically what Steven has taught me, which becomes more obviously true each day.
Steven just beat me to the punch about Michael Smith's car.
Procarnut.. I'm not suggesting I woul abandon the exhaust retard right away in your situation.. my experience is from 13* retard and whatever Michael Smith's timing was. I think it's too extreme. I think with your intake you might be good with just a bit of exhaust cam retard; maybe 7*, maybe less.. I'm not sure what retarding the intake is doing, but it would be cool to vary that separately and see what it does.
[This message has been edited by Steven Snyder (edited 06-11-2008).]
I've been playing with a program to see what each change would show. Ofcoarse it's a database and not real life. However the graph is exstreamly close to my dyno sheet except showing higher on the scale. Now with everyone saying their dyno was 10% low, I should have more power than what was printed. Who knows? 218 + 21 = 239HP? and lean? plus not to full rpm range on the dyno. When I was deciding on the cam timing, I ran several combinations and finally chose the -6/-16 for the Hp out put. Approxamitly 300HP. I had alot more power than I have now but since i was 180* out on one bank it destroyed several belts and one chain. Durability is worth more than I thought. I might just go back to stock but I ran the numbers and the power is substantially lower by the program. I'm may consider going back to stock since gas is more exspensive.
Just curious....Have you seen any difference with Fuel consuption going back to stock cam timming? I may end up driving my car more and fuel is an issue.
So far my best milage has been 32mpg but actually averaged around 23 to 26 mpg with the 13* retard exhaust cam. It varries because by driving changes, habbits and road conditions. The 32 MPG was all highway with a tail wind all the way.
Just curious....Have you seen any difference with Fuel consuption going back to stock cam timming? I may end up driving my car more and fuel is an issue.
So far my best milage has been 32mpg but actually averaged around 23 to 26 mpg with the 13* retard exhaust cam. It varries because by driving changes, habbits and road conditions. The 32 MPG was all highway with a tail wind all the way.
I've managed to get 30 mpg with the 13* exhaust cam setting and a 4.10 4 speed but thats being very careful to not be leadfooted which is hard to do
I am going to be putting a 3.4 DOHC into my Ferrari replica project and I just got off the phone with a fellow that is not too far away from Calgary that has a brand new 91-93 3.4 DOHC crate engine never been in a car that has a broken bolt hole on one head. He said he got tha pile of engines that were frieght damage so items on the outside of the engines are damaged or missing so he got them cheap so he is selling cheap. I originally called him about a 3.4 pushrod I want to replace a bum engine in my other Fiero with after swapping in the Fiero accessories and he said he had a DOHC as well that he was having trouble getting rid of.
I already have a '95 DOHC from SourMug (Nolan) in parts in my garage so rather than building up the current one at a quoted price of $3500.00 if I had someone else do it, I was wondering if I could swap the damaged head from the new motor with the head I have in the garage.
So, asking a little more concisely, will a '95 head fit on a 91-93 block? If yes, do I need to swap out both heads or just the one?
No but I got water in my basement and have had to shop vac several times ..I am sooo sick of this rain..its keeping me from getting anything done! Thats were my wiring harness shop is. Hopefully the rain is over so we can get a breather ..
[This message has been edited by Erik (edited 06-14-2008).]
So, asking a little more concisely, will a '95 head fit on a 91-93 block? If yes, do I need to swap out both heads or just the one?
Thanks much Don
Of course it will. The cam gears are a bit different (In a good way) with the 94-95 heads. They have a different locking mechanism, and are the desired cam setup.
Swap the heads and cam carriers onto the new motor with fresh seals and you're in good shape. I highly recommend a head deck and rebuild while you're at it.
[This message has been edited by Emc209i (edited 06-15-2008).]
The past two weeks have been a bit rough. I took the time 2 weeks ago to pull the engine to do the timing belt and pullies. As well as fix the leak at the oil filter manifold, which I am convinced was invented by the devil. I put the engine back in and was happy with the way things were going. I vacuumed and charged the A/C and it worked beautifully even in 106 degree weather. I took the car around the block and noticed a new noise coming from the engine. After listening for a little while I pulled off the accessory belt, and then the timing cover. The noise didn't go away. This is what it sounded like.
I removed the timing components because that is where the sound seemed to be coming from, as well as the fact that they were the newest parts to be put on the motor. To my dissapointment, They too were fine.
So... I had to pull the engine again. I was particularly annoyed that I would most likley have to disconnect the A/C Compressor to do it. But I managed to get the engine out by floating the compressor off the engine and hanging it with a piece of welding rod. It was just barely doable.
And its out!
I tore through the engine to find the sourse of the noise I pulled the cam carriers off, the oil pan, the upper intake...
I found NOTHING wrong with the internals of the engine, the bearings looked great, the lifters floated freely. The oil pan was pretty clean, nothing notable in the bottom of it. Actually, I think I built a really good engine.
After more thiking about the noise I decided to look at the timing components a little more. I think I might have wasted a lot of time pulling the engine.
I guess I will replace some gaskets, put it all back to gether and stick it back in the car. Man this is frusterating.
Oh MAN I feel your pain!...I was about to suggest checking the timming belt. Some timming belts had round notches and some squared notches. One of the many problems I got snagged on. 95-96 had a transition between the two types not notched timming belts.
I have a crate engine that is a 96, my engine in the car is a 94. They do have two different types of timing belts. The older ones have square belt teeth, the 96-97 engines have round teeth, probably did this change for noise. I will admit the timing belt is a bit noisy, even when it is in perfect shape.
I just wonder if this noise which I believe is the tensioner sliding in and out on the pivot bolt is a common issue amongst the 3.4 DOHC's. Anyone ever heard of this?
Yeah, I have on other motors (DOHC- 3000GT's, Jetta's, etc) Dude, that sucks that you tore your block apart. Wow.
My Dad overheated his Stealth four months ago because of a broken heater line. Both heads warped and resulted in a huge mess. We rebuilt the entire top end and ordered new heads, as the old heads were warped beyond repair. The first night Mike and Dad cranked it, there was a noise like yours. They trouble shot the entire setup, couldn't find the problem, even with a stethoscope. So they replaced everything on the outside: Belts, pulleys, wp, oil pump, cam bearings, crank bearings, rod bearings... everything except the rods and pistons. It turned out to be a piston. =|
Be happy you found it I guess. You'll know next time eh?
[This message has been edited by Emc209i (edited 06-16-2008).]
On the bright side, I didn't pull the heads off, I didn't take the timing cover off, I don't need to replace any bearings. In all, its not so bad. It is getting a new oil pump though. I just hope that what I found is actually the noise that was driving me up a wall. If I put the engine back in, and it still makes this noise, I will flip my lid. I am going to grind down the idler insert so it fits with far less play then it had. The old components didn't have this much play.
I do have another question though...
The tensioner can only be tightened untill it strikes the mounting bracket behind it. This ocurrs when you get the square nub to about the 4 O'Clock position. Am I supposed to tighten it this far? I always hear apply 12-20 lb-ft. on the square nub to tension the belt. It hits the mounting bracket when this much force is applied.
Could it be possible you may have the wrong belt? Not only is there a diff. between the square and round teeth on the belt, one has more teeth! If you take the two belts the length is the same but the teeth gap is slightly different! I found this out because I wanted to get a GAtorback belt and they didn't have one for my application. Ofcoarse now that I said they have the same length, may not change tentioner clocking position.
If you get the "timming belt kit" everything should match. I think that is why they change everything with kits. Correct me if I'm wrong.....but one kit had the belt, tentioner, cogs, idler pulley's, everything for the belt drive. I would check to make sure. The tensioner in your video shouldn't have that kind of slack.
I think that is why they went to round teeth for noise reduction (vibration reduction).
If i remember correctly....I might not...I had to change a few things around. I have a 94 block and cams and 96 heads and intakes. So the cogs didn't exactly match. I had a loud groan from the belt. I ended up using lower or upper cogs for the belt to fit right.
I know I have the right ones, For reference this is the difference:
Yep, more teeth and rounded.
Can't imagine the engine running for more then a few seconds with both types of cogs The timing would wander out pretty quickly. You should have noticed that the teeth didn't line up at all when installing the belt, I find it hard to believe you could make that mistake.
The belt kit was made by ContiTech. It's $200. It included a belt, two idlers with bolts and a tensioner pulley (but no bolt?) My problem was that the pivot sleeve was significantly longer then the bore in the tensioner, so the tensioner would vibrate with the belts tension. I took the excess metal down, and It can't make any noise, but can still rotate as free as it is supposed to. It'll be a couple of days before the engine goes back in to see if its all better.
I still think the design for the 3.4 DOHC is a crap. It only makes up for it with performance, potential for so much more perfornance, and of course, the tune the engine sings when it hits the powerband.
Well I did the belt change in the car. I never thought there was a diff. between them since everything else was the same. However I only ran it on initial test crank....fortunatly before I put everything back.
I still think the design for the 3.4 DOHC is a crap. It only makes up for it with performance, potential for so much more perfornance, and of course, the tune the engine sings when it hits the powerband.
Look familiar? Its a timing diagram for a 3.4 liter, 90degree V8, Ferrari 348 timing belt setup. It is a 60 hour replacement item, at $100 an hour. Still, hundreds of people appreciate that. It makes their car more expensive feeling. A common problem with their setup is that the drive belt also handles the water pump on the 348. Which also has the tendency to lock up and throw the belt if its driven past the service date.
Why does the tensioner have a lot of oil in it? everyone says it's "Hydraulic" which is total BS. There is no piston, there is no seal. It cannot retract except when removed and manually retracted. So, whats the deal with the oil? It just leaks out anyway. It seems like grease is more appropriate.
My quad 4 on the other hand, used the oil pressure from the main galley to push a piston that would sinch up the chain tensioner.
No but I got water in my basement and have had to shop vac several times ..I am sooo sick of this rain..its keeping me from getting anything done! Thats were my wiring harness shop is. Hopefully the rain is over so we can get a breather ..
Sounds like you need a sump pump. They are not hard to put in yourself. Just find the lowest corner of your basement and cut a hole in the floor the right size for the pump. Install the pump and put a grate over it. Then it will automatically pump water out of your basement every time water goes into the hole and it will keep your basement dry. Here is a $50 pump that you can use for this purpose:
You can also go into even more complex basement drainage plans by cutting channels into your basement floor going to the sump pump and then covering the channels with either concrete strips or long thin grates.
[This message has been edited by Doug85GT (edited 06-17-2008).]
The timing would wander out pretty quickly. You should have noticed that the teeth didn't line up at all when installing the belt, I find it hard to believe you could make that mistake.
