First thanks to Cold fire for a good system. Just finished the trans, new A&A drum to cure the 3rd gear slip. Went to start it ,fired once then POP. Flipped the upper half of the intake upside down and burned. Hit the fire bottle got out and hit it with a small puff from the garage extinguisher to make sure it was out. The lower intake needs to be welded. Everything cleaned up pretty good with help from my wife. I cant find all the little parts of the intake, so I think I'll pull the heads to check. Can't afford to wreck anymore pieces. I was all set to leave for the Memorial race at Mid Michigan and get my license. Could have been a lot worse.
Doug

Glad it didn't get worse! fast thinking on your part. picture didn't work.

Bummer Doug.... glad it wasnt worse

Really glad it wasn't worse! Couldn't see the picture, how bad did it hurt the car? Send the new one to Bob George and have him fill in the floor and install blow off valves in it so that it doesn't happen again.

Think there wasn't some force,check the throttle cable.

WOW sorry to hear but it looks fixable.I hope from the cam to the carb everything else is ok!

And of coarse there's a fire nozzle in the interior as well.

thank god you got it out quick

Sorry to see that Doug. I know what thats like as I have had 2 of them blow up on me. One was at start up and the other was as I was driving through the pit area to go get teched in!!! Bob George put these blow off valves on my intake and I also put in the inserts in and have not had that issues since then. I know there are plenty of people who have never had an issue like that with these intakes but after having it happen to me twice I had to do something. The Wilson blow off valves also work very good!!!




Russ

YIKES!! this post is scaring the (bleep) out of me.i think mine needs to have those mod's done.

Before this happened to me I would have thought a mechanical issue or driver error. I always turn the pump off before shutting the engine off. Prime the carbs and then turn the pump off until it's running. I think I kicked the throttle 4 times total. The only thing that I see at all is the #7 plug is carbon fouled. Looks like it hasn't been firing, at least on this start up. I will build some type of blow off now.
Doug

Glad you got it out before doing any further damage. Trust me I feel your pain....

ouch ! that sucks hope the rest of the engine is ok, now ya got me thinkin i just put the indy tunnel ram back on mine but i never had it do that ? must have somthing to do with the fuel in that big plenum ??? and a miss fire ??

Wow!! Doug...I am glad it wasn't any worse than that!! Good thinking on your part!

That happened to son Kyle's car....we had a nice little fire going. Pulled all of the bolts out of the bottom, they redrilled and tapped them to a bigger size.

It does have pop off valves on it now! That was enough fun and excitement to fill an evening.

Hate to see that happen to such well put together car – the blow-off valves are a must with that intake – check your carbs now as the explosion usually takes out the part of the casting where the air mixture screws seat into – especially if they are edelbrocks as they are more prone to the problem than the carters.

The big bang probably started with the #7 plug being it was fouled – possibly your lash may have been slightly off or that valve was hanging a little being the engine was cold. It does not take much to set them off.

OUCH! Doug hate to see that man!

We have done it twice as well, Put on a set of those Wilson nitrous blow off valves and you wont have another problem.

Casey

REALLY glad to see you saved it! That could have been catastrophic! Such a beautiful car, hope you get it fixed up soon.

one more valve option, heres my speedtech valve fits nice between carbs, sad this happened hope fix goes well. bob.

OH MY!

Sorry to see this Doug and hope the repair is as painless as possible

Man! Sorry to see this Dave! Def need a blow-off on those manifolds. Glad u had the fire system

The big issue with these manifolds is the flat or depressed areas at the front and back corners(left to right).If you pump fuel from the accelerator pumps before starting or have a float or needle valve issue the raw fuel puddles in these areas and the slightest kick back or backfire ignites the fuel and fumes causing a hard explosion.If you look in the manifold you will see the blackened area where the fuel/fumes ignited.
Indy has an insert(epoxy) that helps but fuel can get behind and under it,it also kills the volume of the intake which makes this intake work so well on large cubic inch engines.We maximize the volume buy welding in small angled ramps at these areas.We also install the Wilson or similar valves for extra insurance.

I decided to go to the Track with my son and leave the problems sit a few days. I'll pull the heads today to check for any pieces that might have made it inside of the ports. Now that I think about it spinning the motor with ignition off probably contributed. Bob, do you have any pictures of the pieces you weld in? I like Rat Patrols blow off valve. Anybody know where to get that style valve/plate? It has a MSD 7al2 box w/crank trigger at 32 degrees. I'll check the carbs as well. In fact as long as the steering linkage off to remove the headers Ill pop the pan for a bearing check as well.
Doug

Man, really sorry 2 c this after all of the beautifull and hard work you put into your car and hopefully you`ll be back up and running soon enuff............

Yep yep that sucks

You are taking it better than I would, I would still be pouting about that intake blowing up

Good luck getting it fixed and going again. still cant wait to see the car

Doug when that happen to us we put longer bolts in and was racing in an hour. I know you want to make sure things are all right but remember it blew out not suck in so everything went out. You will probably not find anything in the heads .

Pulled the heads,found no shrapnel. My theory was if an intake was open the pressure could have sent a piece down the hole. As long as the steering linkage and diaper were off I pulled the pan and checked the rod bearings. I'll put the heads back on tomorrow. Has anyone back fired one of these after the blow off valve install? I can see why it popped the top. Only had 3 threads of engagement of the lid bolts. Total carnage. Melted 2 temp sensor wires,1 vacuum line, 1 accelerator pump(there plastic on Eddelbrocks,throttle cable, fill the fire bottle, distributor rotor (Intake knocked the distributor cap off), very lucky.

I have backfired mine after I had the Bob George made blow off valves on and they worked. I have also seen guys with the Wilson valves backfire and they also work well. And yes the top bolts are short and I replaced all of mine with longer ones. Indy always told me there was no issue with these intakes but said the short bolts are a safeguard in case it did happen The epoxy inserts from Indy also help with the puddling of fuel and I did install them too. If you want I can get a pic of what they look like intsalled.

Just seems like with the big plenum volume backfires will happen and even more so when cold starting. I knew there was always a chance on start up but my 2nd blowup was while driving through the pits so that was different.

Russ