1966 Barracuda "car ****"
Hi again... It's been pretty much one year since my last post: I lost much time, hair and nerves with some engine trouble, so I decided to come back, as soon as this obstacle is solved.
Had a water leak between block and head. Finding the cause for this, was not easy and time consuming. I suppose, it was a combination of not having machined the required rough average on the surfaces in combination with the Cometic MLS gaskets. These are custom made (part #H2594SP9051S - the 51 stands for .051 thickness) with the correct bore of 3.700" and fit a 273 small block HiPo engine. If we compare this gasket with Cometics standard product (part #C5622-051 4.080 MLS HEAD GASKET - that has not the correct bore size) we notice, that the standards have much more embossed areas around water- and oil-holes, but none around the bolt-holes. In the custom-made Gasket it is the other way round. So the standard gasket allows much more pressure to the water holes to keep the sealed. The outer bridle on the custom gasket doesn’t help, if there is water protruding from the inside. This is my personal opinion. I had contact with cometic, but they do not seem to be really interested.
Cometic custom gasket (see embossements around plug holes)
Well, at least I decided to put on Fel-Pro 521SD Heavy Duty gaskets (the one with the blue stripes). They provide enough thickness and seal that engine properly. At this point I don't care about compression loss anymore...
But before I got to this point, I noticed that there was a crack in one of the new valves. Since I didn't know how deep and serious it was I decided to bring it back to the shop. They ordered new parts but wrong valves arrived from U.S. --> waiting again.
Me and my brother Ben fired that engine few days ago outside the car. I built a small test stand and could check a few data. We were able to adjust the carter carb.
2500 r.p.m. 47° advance (idle hot - with vacuum ported)
750 r.p.m. 10° advance (without vacuum)
750 r.p.m. 20° advance (with vacuum ported)
vacuum idle hot at 750 r.p.m. 500 Millibar (14.7 inhg)
oil pressure 5.3 bar (approx. 76 psi) snapshot...don't know what r.p.m.
But check out the video-clip:
Hi again... It's been pretty much one year since my last post: I lost much time, hair and nerves with some engine trouble, so I decided to come back, as soon as this obstacle is solved.
Had a water leak between block and head. Finding the cause for this, was not easy and time consuming. I suppose, it was a combination of not having machined the required rough average on the surfaces in combination with the Cometic MLS gaskets. These are custom made (part #H2594SP9051S - the 51 stands for .051 thickness) with the correct bore of 3.700" and fit a 273 small block HiPo engine. If we compare this gasket with Cometics standard product (part #C5622-051 4.080 MLS HEAD GASKET - that has not the correct bore size) we notice, that the standards have much more embossed areas around water- and oil-holes, but none around the bolt-holes. In the custom-made Gasket it is the other way round. So the standard gasket allows much more pressure to the water holes to keep the sealed. The outer bridle on the custom gasket doesn’t help, if there is water protruding from the inside. This is my personal opinion. I had contact with cometic, but they do not seem to be really interested.
Cometic custom gasket (see embossements around plug holes)
Well, at least I decided to put on Fel-Pro 521SD Heavy Duty gaskets (the one with the blue stripes). They provide enough thickness and seal that engine properly. At this point I don't care about compression loss anymore...
But before I got to this point, I noticed that there was a crack in one of the new valves. Since I didn't know how deep and serious it was I decided to bring it back to the shop. They ordered new parts but wrong valves arrived from U.S. --> waiting again.
Me and my brother Ben fired that engine few days ago outside the car. I built a small test stand and could check a few data. We were able to adjust the carter carb.
2500 r.p.m. 47° advance (idle hot - with vacuum ported)
750 r.p.m. 10° advance (without vacuum)
750 r.p.m. 20° advance (with vacuum ported)
vacuum idle hot at 750 r.p.m. 500 Millibar (14.7 inhg)
oil pressure 5.3 bar (approx. 76 psi) snapshot...don't know what r.p.m.
But check out the video-clip: