Maximum RPM limits.........?

[david buschur]

I've searched these forums from one end to the other. Cannot find the answer I am looking for so I have to ask one.

I've owned an '87 WE4 for about 7-8 years. Beautiful car, 34,000 miles. I've had nothing but problems with trying to make it go fast. One after another and have never fully tracked it down, until recently.

I've always run race gas in the car. Well not sure what kind of crap I got into but a mixture of water and some type of seriously thick goo finally did the entire fuel system in to the point of no return. Return line was completely plugged shut, couldn't even force 100 psi air through it.

Long story short, I have decided to turn the car into a full TSM car. I don't drive it enough to care.

Doing a 109 engine build. Steel crank, forged rods, lightweight forged pistons, front, rear and center mains, girdle, balanced etc. This is the second one of these I built this way, the first I sold as I lost interest in the car with the problems I couldn't find. We actually machine the tops of the mains perfectly flat to the oil pan rail and then bolt the girdle on, it's bad ass to say the least.

Finally, here is the question. What is the maximum RPM you guys are running on an the fast 109 blocks? One just went 8.90's, it has to take some RPM to run that fast. The stock block in my car now has been to 6100 rpm numerous times. Is 7,000 rpm possible?

Thanks for any input. I'm an RPM freak, guess I'm use to building 10,000+ rpm 4 cylinders making 1,000 HP

David Buschur

 

[ChrisCairns]

I hit 7000 once as recorded on FAST. Not normally though, I had the tranny set to shift at 6500. The 7000 was when I forgot (duh) to shift out of 2nd.

 

[david buschur]

Chris,

Thanks for the input. So you regularly shift the 109 at 6500 rpm? Do you have quite a few passes on it doing this?

David Buschur

 

[psiedv6]

I've searched these forums from one end to the other. Cannot find the answer I am looking for so I have to ask one.

I've owned an '87 WE4 for about 7-8 years. Beautiful car, 34,000 miles. I've had nothing but problems with trying to make it go fast. One after another and have never fully tracked it down, until recently.

I've always run race gas in the car. Well not sure what kind of crap I got into but a mixture of water and some type of seriously thick goo finally did the entire fuel system in to the point of no return. Return line was completely plugged shut, couldn't even force 100 psi air through it.

Long story short, I have decided to turn the car into a full TSM car. I don't drive it enough to care.

Doing a 109 engine build. Steel crank, forged rods, lightweight forged pistons, front, rear and center mains, girdle, balanced etc. This is the second one of these I built this way, the first I sold as I lost interest in the car with the problems I couldn't find. We actually machine the tops of the mains perfectly flat to the oil pan rail and then bolt the girdle on, it's bad ass to say the least.

Finally, here is the question. What is the maximum RPM you guys are running on an the fast 109 blocks? One just went 8.90's, it has to take some RPM to run that fast. The stock block in my car now has been to 6100 rpm numerous times. Is 7,000 rpm possible?

Thanks for any input. I'm an RPM freak, guess I'm use to building 10,000+ rpm 4 cylinders making 1,000 HP

David Buschur

Exturnal balance likes 5000-5500 and inturnal balance likes RPM till you see a power loss. There is no reson to spin a motor at high RPM if it does not flow or make power there. The only time you would need alot of RPM is with stage II heads that flow like crazy and like RPM.

And yes there is a 109 block that when 8.90's but there is more money in that block than a new alumimun TA block. It is called cubic dollors


long story short, look for power not RPM and if it keeps pulling keep letting it rev.

 

[ChrisCairns]

Chris,

Thanks for the input. So you regularly shift the 109 at 6500 rpm? Do you have quite a few passes on it doing this?

David Buschur

A year and a half of low 10's, one high 9. That was a beautiful engine. It would probably still be running if ......and this is your choice....

(a) hadn't run out of AC oil filters and had used a Fram instead....

or

(b) I forgot to tighten the filter.

( Personally I think it was B...:biggrin

The oil seal ring had pushed out to one side and it pumped out most of the oil. It lost oil pressure at over 6000 rpm, then caught on fire while doing over 100mph. I was told the bottom of the car was just a huge fireball. The fire mostly went out by itself once I'd stopped although I had to hit one area under the hood with the extinquisher. Once back in the pits I found the filter loose, (took me a long time to find that,) tightened it, put 3 quarts of oil in it and went racing. Next pass it took out the crank, but not the girdled block. I still have that block and it "just" has a small piece of cylinder skirt missing and a small crack in the same location. Someday I may use it for a stock rebuild.

 

[psiedv6]

A year and a half of low 10's, one high 9. That was a beautiful engine. It would probably still be running if ......and this is your choice....

(a) hadn't run out of AC oil filters and had used a Fram instead....

or

(b) I forgot to tighten the filter.

( Personally I think it was B...:biggrin

The oil seal ring had pushed out to one side and it pumped out most of the oil. It lost oil pressure at over 6000 rpm, then caught on fire while doing over 100mph. I was told the bottom of the car was just a huge fireball. The fire mostly went out by itself once I'd stopped although I had to hit one area under the hood with the extinquisher. Once back in the pits I found the filter loose, (took me a long time to find that,) tightened it, put 3 quarts of oil in it and went racing. Next pass it took out the crank, but not the girdled block. I still have that block and it "just" has a small piece of cylinder skirt missing and a small crack in the same location. Someday I may use it for a stock rebuild.

Chris, that same sh!t happend to me about 12 years ago in my 86 with the Fram fitter but I was at the street races, racing a street bike. There was no fire, you can just say I smoked the street bike (LOL)

Also my brother crashed a 63 427 lightweight Ford Galixie (very rare and alot of $$$$) at the drags from blowing a ring on a Fram filter. Oil went under the rear tires and he hit the gard rail and rolled it 4 and a 1/2 times going about 120 mph half track, it was a low 9 second car worth about 85k, it was scaped :frown:

 

[Dominic]

I spun my internal balance 109 block motor 7500-7700 with stock crank and rods, 2 center billet caps, no girdle and TRW's with JE pins. Motor had about 9.25 compression. It ran for about a year and the block cracked all the way around just below the cylinders. Won't matter what kinda girdle you have when the block breaks up there. If i were to build the same engine again i would use hardblock, a girdle, and aluminum rods. Don't be afraid to put some camshaft and compression to it either.

 

[david buschur]

Thanks Chris and Dominic. I wanted to hear from guys actually do it, those are the only opinions I am looking for.

RPM is HP, please don't tell me not to spin an engine.

7500-7700 rpm is killer. That's a lot of RPM. The break throughs that have been made with the steel caps and girdles are pretty damn amazing.

Really looking forward to getting this all together. Parts are trickling in now so I can start re-assembling some of the car.

Champion fuel rails showed up today, those are some nice pieces.

I'm going to run the car with the Champion CNC'd iron heads I have first and see how fast it goes. I like the weight break for the heads. Guess my goal is 9.50's............see how that goes. The car has been one PITA after another trying to go fast with it. Now that I have the problem found it should get easy. We build enough high HP fast stuff here that I just don't see it being very difficult to make the car go fast.

 

[ChrisCairns]

Doing a 109 engine build. Steel crank, forged rods, lightweight forged pistons, front, rear and center mains, girdle, balanced etc. This is the second one of these I built this way, the first I sold as I lost interest in the car with the problems I couldn't find. We actually machine the tops of the mains perfectly flat to the oil pan rail and then bolt the girdle on, it's bad ass to say the least.

Finally, here is the question. What is the maximum RPM you guys are running on an the fast 109 blocks?
David Buschur

I forgot to say one thing Dave.

I have another block at the machinist's right now. It has a steel stroker crank and forged rods like yours. Plus I'm going to run solid lifters. One of the better Buick engine builders told me I would be able to turn it to 7500 rpm. So I would think you could also if you use solid lifters.

Bob....glad you recited your problems with Fram filters also. Perhaps I can change my vote from "B" to "A" now and stop beating on myself for being an idiot.

 

[bison]

I cant say for sure but id bet the top TSM engines are spinning 7500-8000 rpm. Ive heard of one particular destroked TSM engine revving to over 8000rpm. Some of which have aluminum rods. This is evident assuming gearing in the high 3's and a 29" slick viewing the mph they are laying down. These blocks are typically hand selected out of many blocks for various reasons and then hard blocked half way up the cylinders or more. It has also been noted to me by a highly reputable builder that the cylinders still move around after hard blocking and take another hone after running to get them truly round. These guys dont just settle for what they have on hand. They spend thousands of $ to gain a little advantage. Also keep in mind that they are running non stage 2 heads, so the flow potential is there regardless. If you plan on over 6500 rpm i would build a solid roller engine, steel crank and some billet rods with 9.5-10.0 comp ratio. Run the thinnest oil rings you can. Plan on spending a lot of extra $ on the cylinder heads also. Your pretty much limited on turbo selection so you have to make up for it elsewhere, which is in the cam, head, and intake. Also plan on having a huge air to air intercooler specifically fabbed for your application. There is apparently a lot to be gained with the intercooler. Ive heard reports of 15 degrees over ambient with 26 psi of boost on a TSM engine. That is quite efficient if you think about it. For every ten degrees your looking at a gain or loss of about 1%. 4% on an engine making 800hp is a lot when running in a tough class.

 

[david buschur]

Yes, so it seems from some PM's I have gotten by some of the guys I'd consider the most reputable/knowledgable in this business that 7,000+ rpm is not abnormal from a properly built 109. I was hoping to find this out.

I am using a hydraulic roller. 7,000 rpm should be enough for me, I'd like to keep it lower, just looking for a safety net in my mind

I have a large FMIC on the car already. I will do some datalogging of IAT's once the car is up and running and see just how good it is. I can fab up something else pretty quick if I need to change. This is the largest one from years ago that Charged Air Systems made.

My daily driven EVO has gone 9.97 at 142 mph, the IAT's with 30+psi of boost only raises from 78 degrees to 102 on a pass. This is with a much smaller turbo than I will be running on the Buick. I have a kick butt FMIC core that should transfer over to the Buick. I think I can even use the same end tank design. We use the same core on our EVO that runs 8.95 at 164 mph, that car gains about 29 degrees on a pass but that turbo was a GT4272with a whole buncha boost I think the core would work really well on the Buick.

I'm going nuts waiting on all the parts to show up to assemble the car!

 

[psiedv6]

Bob....glad you recited your problems with Fram filters also. Perhaps I can change my vote from "B" to "A" now and stop beating on myself for being an idiot.

Chris, Don't think you did something wrong with the filter, im sure it was tight, they are just junk.

Is that motor getting machined the 109 block I sent you?

RPM is HP, please don't tell me not to spin an engine.

Wow RPM is house power, if that is the case shift at 11000 with a hydraulic cam and you will do just fine

 

[david buschur]

psiedv6,

There you go again.....call up some F1 teams and talk them out of running higher RPM while you are at it! haha

Of course there are things that limit IF you can run more RPM and make power doing it.

Don't worry, if you stick around long enough and listen you'll learn about the benefits of RPM. I have hope for you.

 

[psiedv6]

long story short, look for power not RPM and if it keeps pulling keep letting it rev.

I see what I said, did you :biggrin:

 

[V6RACER]

I'm going through the traps at 5800 rpm FWIW. It takes more than RPM to make power but a properly built combination will benefit from higher RPMs. Most people aren't going to tell you exactly what they are doing in a heads up class but if you listen to the right people you will learn what you need to buy/build to make it work.


OBTW, I know of a few 8000+ rpm 109s

 

[Dominic]

Run the thinnest oil rings you can. .

I would usualy use a standard tension 3/16 or 7/32 oil ring in a boosted engine, if you get any oil in the combustion chamber at high boost it will lower the octane of the fuel and cause detonation.

just my .02 cents

 

[86brick]

I'm sure Billy Anderson must be turning some serious RPMs with his destroked 209ci 109 TSM motor....

 

[turbo2nr]

You guys research Buscher Racing and their success in racing. If he is going TSM......it's going to be a great year of racing to watch!

 

[david buschur]

Thanks turbo2nr Around here I am just so dumbass asking questions! haha

It will be interesting to see what my car will do. Looks like the iron heads are being judged as the worste part of my combination. My goal is 9.50's, I'm not out to set any records. I'd just like to put the car together make it run reliably. Tired of sitting in the garage not running right.

I have so many parts on order now I am loosing track of what I have coming in and what I don't! haha

I will be open with my combination when it's done whether it works or not, I expect it to work. I guess everyone does. I don't think anyone puts a car together thinking, "Man this is stupid, this combination will never work."

 

[bison]

I would usualy use a standard tension 3/16 or 7/32 oil ring in a boosted engine, if you get any oil in the combustion chamber at high boost it will lower the octane of the fuel and cause detonation.

just my .02 cents

Not when your revving the engine to 7500+rpm. The boost helps the rings seal even better if the bores are round. I meant to include compression rings also on that post. But got ahead of myself.