I am planing a 700-800hp supercharged LT1 engine. If I have the block half filled, how will it effect cooling? Also, how much will this cut down on bottom end flex under high load? Is this something for a "race only" car, or will it be safe for a daily driver with the ocasional long trip?

 

A search is always good
http://web.camaross.com/forums/showt...threadid=23473
http://web.camaross.com/forums/showt...threadid=57959

 

My block is filled with Devcon all the way up to or just below the knock sensor hole. Never seen a problem when the motor was 383ci n/a overheating. I had a 383 LT1 with ATI Dominator blower setup from Modern Musclecar and that block was not filled to best of my knowledge but that motor always seemed to run hot when in the summer getting in to the boost both the water pump was changed thermastat,fans where OK both of them. The only thing I didn't try was going to a different radiator say like a big Griffin.

You shouldn't have any problems but then again you might be running a ton of boost! Those intercoolers are worth there weight in gold!

Good Luck!

 

Just curious why you feel block fill is necessary at that HP level?

 

The engine builder at the time of the buildup for the 383ci n/a had some experiance in the past with seening other 396ci LT1 engines have problems sometimes with cracking into the water jackets and up along the bore. This was mainly occuring in the very lower portion of the bore and areas of the block that where clearenced for the increased stroke or rod.

I should have been more clear regarding the motor. The motor was originaly being mocked up as 396ci with 3.875 stroke using 5.875 rod. The rods at the time where profiled for stroker combination from the manufacture but with any stroker there always is extra clearancing to the LT1 block that must be done.

The motor was filled with Devcon to help bore shift and help with deck stiffness not mention aid in the thin areas of lower portion of the bore that had been clearenced. So for that reason the builder filled the block.

Really the motor was intended to see alot of nitrous assistance. The majority of the time the motor was ran n/a. The car wasn't a daily driver but really a weekend hot rod. Issues with the crank manufacture regarding machining errors and time delays I got tired of waiting and I had a 3.750 stroke crank laying around so I said lets use this until the other manufacture can get there act together and build a crank that will be machined correctly. I figure for $1200.00 I want what I paid for. So that is how the 383ci comes into play. If it wasn't for the high cylinder psi the motor was to see there should be no reason why a block normally should see block filler with under 383ci assuming a person isn't trying to come up with some wild rod stroke ratio using crazy long rods. Per my engine builder. The Devcon didn't hurt performance or the cooling aspect of it but was a good precaustion to take with either high output nitrous or blown setup. If it didn't effect cooling I didn't care.

I asked Wade at ARE about the block having this in it because he is doing a new motor for me this year which is over 396ci and compression is also above 13.1 he said I wouldn't have any problems with it being there and it wasn't a bad idea considering the amount of nitrous the motor will see.

My be some guys get by without using it and thats great but seeing I don't build or come up with the combinations, far be it from me to argue with the experts. All I want is the max. power they can pull out of the motor within its limits and what I know how to tune or work with, in this case I know nitrous very well!

Injuneer, I visited your web site and I really must say that's a very nice car you built! I was wondering about your dry system, does the Motec system ECM control timing either by adding or subtracting timing based off your O2 sensor when in closed loop mode? Also will that system add fuel at the injector if need be say if the O2 sensor starts to log a lien AF ratio when the nitrous is engaged? Don't know to many people that have or can afford the Motec systems not to mention to be able to afford the tech help if needing guidence. I thought I had money in my car's until I seen yours. LOL! Nice to enjoy the fruits of our labor.

Happy Motoring,
Jim

 

My question about "why the fill" was purely educational. I have only really seen two real high HP LT1 buildups real close.... both Vortech blowers on 383's.... one about 1,000HP and the other 1,125HP. Niether used block fill. The higher HP block was sold and is being reused in an 1,100HP nitrous motor. Testing revealed it was still sound. I have also seen some cooling issues with blocks that were overfilled. But I have no real knowledge about when to "fill".... I'm just trying to learn.

My MoTeC was a bargain... $1,500 used. The IEX 8-channel ignition driver and the tuning/logging software and cable were "extra" at MoTeC prices.

The system operates open loop at all times..... wideband closed loop operation is a $1,300 "option". Timing and fuel tables, both base maps and "nitrous offsets" were developed with approx 24 engine dyno pulls, and verified by numerous chassis dyno pulls. The original tune actually had a 3 step hierarchy.... NA on 94 octane, a 135-shot on 100 octane and the full 275-shot on C16. But eventually it was converted to a single stage 300-shot, and the base tune is mearly to "get it to the line".... if I wanted to drive for extended periods of time NA I would have to swap programs.

At the beginning of each season, I have the tune updated to reflect any changesover the winter, and this year $$$ have been a little short, so I have yet to get the tune verified or run it. Hopefully I am about a month away from experiencing the full potential of coming off the line under full nitrous power .

Fred

 

FWIW I added more Devcon this year. Not sure it's needed, but approaching the 1K hp level it seemed like a good idea.

Rich Krause

 

Thanks guys, I think I will be using a 1/2 fill on my build up. I have not heard of a cooling problem when using filler on the street with only a 1/2 fill. If it will make the factory block stronger, then for the $50 or so it will cost me to do it , its worth it to me.

 

I filled my old 401 about 1/3 the way up, and it ran hotter. It was very hard to keep cool enough road racing.. around town it was ok, but in the summer traffic it would get pretty toasty.

 

One other thing to note when you fill a block. Block fill is a little heavier than water! Front end weight is the main reason that I don't fill my race blocks. I also am making no where near the HP stated in the above posts.

Daren

 

I am looking for specs on how much people have filled there blocks. I am planning on a nasty little combo. should be close to 800RWHP in the first stage. First stage is stock PCM. and 250 N2O.

Second stage is after market ECM and 8,000 shift points and 300+ N2O.

Out of the box my heads flow 320+ before porting started

 

Just a caution: with the additional fill it does run hot. Not suitable for urban stop and go at this point. Water temps will pretty quickly exceed 235 degrees and keep climbing unless the car is moving even though I have the fans coming on at 160 degrees and a 160 degree thermostat. Cruising, I see 185-210 degrees I suppose this implies that better fans would help.

Rich Krause

 

Rich how much do you have in yours? I am looking for more info like yours from people running it. After all I do drive the car in the 2nd worst traffic in the USA

I have heard fill it to the Knock sensor or bottom of the water plugs. Where is your at?

 

Mine is now to the bottom of the freeze plugs, and the high temps are noticibly worse than when it was just an inch or so of fill.

Rich Krause