Tuned Port, TPI installed

[ZK5]

I just got done, Converting my 87 305 TBI motor to an 87 TPI induction. I rebuilt the entire motor first. Specs are 315ci, 10.54 compression with Wiseco forged flat tops. Moly rings, 1.7 ratio Crane gold race roller self centering rockers, Crane cam, springs,retainers and keepers. ported and polished factory 1987 GM heads with screw in studs and new stainless steel valves. and finaly the entire rotating assemlby was balanced.

My question is this. Before the conversion, the motor began making a ticking noise at 4000rpm and higher sounded like the whole valve train went loose all at the same time. So I tore down the top end to check the valves and guides. The guides were pretty well shot and a few of the valves needed replacing. So it was at this time I decided to go ahead with the rebuild and the TPI conversion. The good news is the TPI conversion was a success. The bad news is that damn tick is still there except it appears at 3000rpms and higher instead of 4000.

Could this noise possibly be realted to poor timing and or cold plugs. I havent quite worked all the bugs out of the TPI conversion yet. But it starts and runs great, except for the ticking noise. I wanna say it's pingin but damn if that aint the loudest ping I've ever heard. sounds more like loose rockers. Do ya think changing to hotter plugs might help? Has anyone had a similar problem?

heres some eye candy for ya.

 

[4X4HIGH]

FIrst off the 1.7 rocker ratio you said you have is too much for s SBC beings that factory is 1.5. Secondly, 10.54:1 compression is way to much for iron heads running pump gas. What injectors are you running? Do you have a chip installed? Is it a MAF or speed density system? Do you have the proper knock sensor installed (it is different from the TBI knock sensor)?

 

[Hossbaby50]

The TPI looks good. I am kinda biased though since I have it in my truck too. I can't help you much with your problem as I am not very up on running high compression with large rockers in a TPI motor.

Looks good though. Congrats on getting it running.

Harley

 

[K5MONSTERCHEV]

Looks good man!! /forums/images/graemlins/waytogo.gif

Does it not run too good? What engine did it come off of? Are they 305 ao r350 injectors? Do you have a custom chip? 10.4 is a bit higher then they came with from the factory. If you have the incorrect knock sensor, or if you tightened it down too much then the timing will be off. But I dont think youd hear pinging because the copm will adjust the timing accordingly, just wount run too good.

 

[ZK5]

4X4HIGH -- Why is 1.7 too much for a sbc? Why can't cast iron heads handle the compression? Yes the factory chip was reburned. this is an 87 MAF setup, speed density was not available till years later and besides that a speed density system could not handle all these engine mods without considerable reprogramming due to the MAP sensor. Besides all that, I said the motor made the same noise when it was stock too. So lets not jump to conclusions. And I agree the compression is a lil high but this motor will run fine on pump gas, 93 octane maybe but still pump gas. FYI Stock compression was 9.4 for the 305 in 1987. These heads have been reworked, screw in studs installed as well as heavier springs along with the higher ratio arms. All the 1.7 did was change the valve lift from .401 to .454 (intake) wich increased torque in my case. Duration is still under 210. This lil 305 makes around 380 ft/lbs. and 310 hp and was professionaly built.

K5MONSTERCHEV, Yes the TPI came off an 87 305 iroc. I will however look into the knock sensor since that is the only common link mentioned in this thread that I havent checked.

 

[supersize75k5]

I dont know jack about these sets up or putting one togther other than it can be a real pain..if you get it together and reliable


you are my hero /forums/images/graemlins/thumb.gif big props to you sir, hopefully it puts a smile on your face after the hard work /forums/images/graemlins/thumb.gif

 

[highrider_44s]

congrats on the new motor /forums/images/graemlins/peace.gif /forums/images/graemlins/peace.gifI was thinking about going tpi in my truck but then the big block came into the picture. /forums/images/graemlins/histerical.gif
my brother put one in his nova recintly IIRC it was a 350 he board it out and put in flat tops and a mild cam upgrade and a chip ran good had lots of bottom end wicked throttle response and sounds mean but it falls flat after 4000 i think its a fuel preassure in the rail but whatever /forums/images/graemlins/dunno.gif
i know with his you can hear the injectors rattle but that might just be at a idle /forums/images/graemlins/thinking.gif /forums/images/graemlins/doah.gif
make sure you update how the motor runs after all the kinks are out /forums/images/graemlins/waytogo.gif
sounds like you got one hot mama /forums/images/graemlins/peace.gif /forums/images/graemlins/peace.gif /forums/images/graemlins/peace.gif

 

[4X4HIGH]

To start off with, the only way you will get away with 1.7 ratio rockers is if someone reworked the valve train geometry on the heads to allow the use of 1.7 ratio. This means altering the valve guide angle, rocker stud angle or both. There was no mention of either one of those being altered.

Cast iron heads cannot dissipate heat fast enough to run the high compression you are running on pump gas. If you had aluminum heads that would be a different story and the compression would not be an issue.

The only reason I ask if it was MAF or speed density is because even though it is from an 87 you could have changed it to a speed density system.

The biggest problem you are having is the knock sensor if it is the original one for a TBI truck and not for the TPI camaro set-up.

If the only thing that was done to the heads was having screw-in studs installed then the rocker arm tip is going to be on the wrong part of the valve tip and you are going to start wearing out valve guides in a hurry unless as I mentioned above someone has corrected the valve train geometry. Yes the 1.7 will give you more effective lift at the valve than a 1.5 ratio would but the geometry will not be correct.

Are you running the factory 305 injectors? If so you may find that you are now running on the lean side and that will increase cylinder temperature which will account for pinging, if you so infact are having a pinging problem. Having an adjustable fuel pressure regulator will help some but you should see about some larger injectors as well.


Your system looks great, i'm not trying to offend you or put you down, i'm just trying to help you out. I did a TPI swap onto a 76 blazer several years ago and I had some similiar problems that I was chasing down as well.

Is your TPI set-up ceramic coated or polished or is that some kind of paint? I have a TPI set-up that someday soon I am going to swap onto my 89 blazer and in the past I painted them with a silver metallic color paint which came out looking pretty good but yours seems to have a shine to it.

I just had another thought. When you timed the engine did you first disconnect the EST wire (brown with white stripe)?

 

[ZK5]

I am going to change the knock sensor today, I also agree the rocker ratio is may cause premature valve guide wear but I can't say it will be in a hurry. Aluminum heads are a planned future purchase. The compression ratio is high but it don't run hot and so far it seems to stay around 185,

The intake and headers are ceramic coated, the plenum and runners I polished, The block and heads were painted with that POR-15 engine paint kit (this is great stuff by the way.)

Again I gotta say, This noise was present when the motor was stock. So this is why I am having a hard time believing that the engine mods are the cause. I will swap the knock sensor and the plugs and possibly the injectors. I am also going to check my cylinder pressure, Cause I'm also not convinced my compression is a shigh as I was told it is. Would a reading of less than 165psi indicate that it should be around 10.1 or less? or is this not an accurate way to measure compression

 

[supersize75k5]

How hot does conneticut get? Just wondering?

Traffic here or lack of cooling will murder a truck down here in a hurry /forums/images/graemlins/doah.gif

 

[Ryan B.]

Sweeet! /forums/images/graemlins/peace.gif

My tpi setup has worked out great. Runs awsome and totally reliable since i put it on about 3,000 miles ago. /forums/images/graemlins/thumb.gif
How long did it take you to polish the runners and plenum? Did you sand em first? Polishing my plenum & runners weren't too bad, but I don't think i will ever sand and polish a manifold again. /forums/images/graemlins/crazy.gif /forums/images/graemlins/rotfl.gif

It sounds like since you tore down the top end, and now the tick is still there... could it be in the bottom end? Piston slap? Rod Bearings? Piston wrist pin? Maybe get a stethascope so you can try to track down where the noise is coming from better? Is it making this tick at all RPMS even at idle? or just under load??
Just thinking out loud..
Good luck man..

 

[ZK5]

I just picked up a new knock sensor for the TPI camaro motor, FYI it is the same exact sensor for the TBI truck motor. I installed it anyway and this did not fix the problem.

And No, it aint the bottom end. The motor is all new and the noise can only be heard from the top end

I will look at it again tomorrow, I gotto go to work. I will check for vacuum leaks and reset the idle and timing tomorrow. Then change the plugs.

 

[4X4HIGH]

[ QUOTE ]
The compression ratio is high but it don't run hot and so far it seems to stay around 185,


[/ QUOTE ]

This is where lots of people get confused. Engine temperature and cylinder temperature and two completely different things. You can have an engine that is running perfect as far as engine temp is concerned but be too hot in the cylinders which will cause a ping.

As far as compression readings indicating static compression ratio, yes and no. The higher the compression reading is the more static compression you have, although there is a way to lower the compression reading even though you may have high compression. The way that is done is by using a cam with lots of overlap which bleeds off low end cylinder pressure. A cam of this nature would not be computer friedly at all though.

 

[Ryan B.]

[ QUOTE ]
I just picked up a new knock sensor for the TPI camaro motor, FYI it is the same exact sensor for the TBI truck motor. I installed it anyway and this did not fix the problem.

[/ QUOTE ]


If i were you i'd double check what ecm you are running and what the part number is on the knock sensor you are running.
I ran into some problems with my tpi swap because the knock sensor I had was # 10456289 and Not # 10456549 which is what I needed to function correctly with my ecm # 122730!


When you jumper the A to B terminal, are you getting any trouble codes?

 

[4X4HIGH]

Ryan, you missed a number in the computer number you listed, its 1227730 and he doesn't have that computer since he is running MAF not SD. /forums/images/graemlins/thumb.gif

 

[dyeager535]

You said it made the noise stock...did that include stock rockers and covers?

Just curious if you are perhaps getting some rubbing in there somewhere that is only apparent at higher RPM's from the additional stress?

 

[ZK5]

I have crane roller rockers, screw in studs and polylocks. And aftermarket tall alluminum valve covers and there is no evidence of them rubbing on the covers. I also just realized that I made a mistake earlier in saying the ratio was 1.7, it is not they are 1.6. /forums/images/graemlins/blush.gif
Anyway, the noise is still there. I am wondering if it's the lifters. Is it possible the lifters arent staying pumped up? My oil pressure is high at around 50 psi at idle. And I wouldnt think it's starving for oil because I don't notice a drop in pressure when I rev it. I have also checked fuel pressure and it is right on the money at a steady 34 psi. I replaced the knock sensor again with another one and replaced the ESC. None of this made any difference one way or the other. I guess I can try larger injectors and an adjustable regulator but I would like to be sure that lack of fuel is the problem before I invest in them. /forums/images/graemlins/1zhelp.gif

Is there a way I can check cylinder temperature?