eclou

145k miles, 18# boost, 4 track weekends. First impending sign was the bubbling/overflow of the coolant tank getting worse for 5 mos. Coolant never tested positive for carbon, etc. Vacuum was 16-17 idle, 23 coast. Car made great power. Then after the last event, car would sputter slightly at part throttle, and idle vacuum was only 14. Checked all hoses and no leaks. Let the car sit 2 mos and tried to re-tune today. Was back up to 15-16 idle, no sputter, and awesome power again. 2nd time I nailed the gas and "POOF!!!" - lots of smoke, water temp pegged, car running on 2-3 cylinders. Oh well, that's why I already had squirreled away some Raceware studs, and a WF headgasket.

Porsche-O-Phile

Bummer. Well, changing the head gasket on these cars isn't that bad. At least you don't have to do an oil pan gasket!

Ski

Just put it on a trailer, tow it down to Corpus and give it to Jim , he does them in a day after all the practice he's had..

eclou

Hey, looking to confirm a couple things from the Rennlist Hive mind:

1)Raceware stud installation via Songzz:

" Replace headgasket, torque down (RACEWARE) 20lbs, wait overnight then torque to 50 lbs wait 3 hours... finally torque 80lbs and that's it. No need to retorque."


2) I remember a thread about sealing the HG around a water passage in one of the corners since there is no raised boss near a stud. Seemed to be a source of coolant leak. Can't find it via "search"

Thanks

jwl

Raceware specifies a re-torque after one heat cycle. The thinking is that the gasket will compress some during engine warm up. It's a real PITA having to pull the cam tower twice but necessary if you don't what a leaky gasket...I learned the hard way.

BTW, we going to see you at TWS in Feb. ?

eclou

I was planning on being at TWS this month no less. Feb for sure if I can get the HG completed.

Sam Lin

You'll be able to tell the corner to seal when you pull the head, to help your search I believe the pic was posted by TonyG. Not a coolant leak, but keeping coolant off a small bolt so it didn't corrode itself in there. Retorque after a heat cycle or 2, Songzzz' procedure is wrong and useless. Install the studs into the block with Loctite and tension them while it sets.

Sam

eclou

Found it

https://rennlist.com/forums/showthre...0&page=2&pp=15

m42racer

My advise is to inspect the stud lengths before removing the nuts. Is there sufficient threads sticking through nuts. Install studs with no Locktite. Make sure the threaded bores are clean. Wind the studs in by hand with anti seize grease or some pipe sealant. check the heights. Then use a MLS Gasket, not the stock fibre type. The MLS gaskets do not require retorquing. Use standard torque procedures.
Any one telling you the MLS Gaskets do not work, either have other problems or did not install correctly. This way it saves the removal of the Cam Housing again.

pk951

Quote from Mr Gasket

EXCESSIVE bolt loading will cause problems. Many backyard mecanics think that if 50 Ft. lbs of torque is good then 60 is better. In fact dynomometer testing has shown that less is best in most instances. Indeed extra horsepower maybe gotten by being "torque frugal". Why??? The more torque that is applied onto the block the more chance of distortion. This distortion is usually seen at the weakest places at the narrowes point of the bore and at the top of the cylinder. At the top of the cylinder where the compression pressures are always greatest any excess distortion will nullify any benefit of that extra clamping force. Blow-by of gasses will cause premature gasket burn through and less horsepower. "Less maybe best".

Just some food for thought.

HY M8NC

I agree to heat cycle the motor, and re-torque the bolts. That procedure might have worked for Songzz, but I think that's taking a fairly big chance over the cost of time and gaskets. Just my $0.02.

m42racer

pk951,

You are absolutely correct. In fact, I read here about the repair of Blocks (honing) but never the use of a torque Plate. Distorsion of these Blocks is big, in fact the 2.5L Blocks are some of the worse. A huge advantage of the MLS gasket is that it requires less clamping force compared to the fibre type, as it does not crush. This then puts less distorsion into the Block, keeps the bores round and the Piston Ring seal better. Measuring the boires for size and concentricity should be done with a Torque Plate attached. I have been shown where the deck surface actually warps slightly when the Head Bolts are torqued down. The sides of the deck twist more in the center than at each end. This is why the Deck Plate was done and is a good idea. Anything to tie the whole thing together makes alot of sense.

David Floyd

m42racer,
How is that deck plate working ? any new info on your engine build ?

Sorry for the hijack

m42racer

The new engine has run on several occasions, (dyno), in different spec's. The Deck Plate is working very well. Together with the MLS H/G, new Wasted Head Studs, Stepped Head Washers, the package is working very well. More of a engineering upgrade, solving issues that have shown in the past to be a problem.

The new engine has gone thro many changes as the parts were finished and tested. At present the parts are been made to have on the shelf. The above parts are finished, along with the Big Valve Cylinder Heads, and many other parts. I know the new EFI systems took a lot of the time, but the upgrades are well worth it. I have seen the new V5 and the system is really good. Staged Injection will help many with better idle and low end transistions. The new Intake Manifold is almost finished. It has gone thro several changes to get the best possible all round performance, along with keeping pace with the new EFI upgrades. It was (manifold) finished, tested and ready for production, then scraped so that dual Fuel Injectors could be fitted to each port. This is a 4 Butterfly system with a 5th as a race option. As others are working on these systems too, I have been sworn to silence until it is fully finished. I can tell you for those who do not wish to upgrade to a multi butterfly system, there is a new larger single Throttle Body housing been made that will fit to a modified stock Intake Plenum. I know that some other PD engine customers have seen some of the parts in development, as most of us are getting some of them first. It has been a long time, but I can say it will be worth the wait. I have seen first hand how long it takes to get these parts developed and made. I have seen customer Blocks get the Deck Plates fitted, along with the Girdle mod etc. Some customers have had their Heads upgraded also, so some of the parts are getting out there. It seems my engine will be the last, as it is the mule for testing all of these new parts.

eclou

Pics of the pistons - notice each one has been kissed by the valves previously