I need a 1.8mm MHG. Will a 1.4mm be ok?

icey756 · 08-17-2012, 11:43 PM

I plan on getting a 1.4mm MHG made by titan motor sports. After I got everything back from the machine shop I added up the numbers and It came out to me needing a 1.8mm HG. Will a 1.4mm be ok or will that be too close? I want the Titan MHG because I read that its more forgiving than an HKS or Greddy. Please get back to me quickly if possible. Want to get it ordered asap. Thanks.

icey756 · 08-18-2012, 03:05 PM

Will someone please let me know. I dont want my valves to be hitting my pistons. I know it raises the compression ratio but i dont want it to raise it too much that something goes wrong

btwilson86 · 08-18-2012, 06:25 PM

In stock configuration, these are non-interference engines; you can have a valve fully open and the piston at the top of its stroke, and there will be no contact. Even in an interference engine, the timing would have to be off a considerable amount in order for pistons and valves to make contact. I can't say for sure, but I'm fairly confident that .4 mm will not be enough of a difference to cause contact between the pistons and valves (especially if it is timed properly).

cre · 08-18-2012, 07:28 PM

No it's not enough to turn the engine into an interference motor.

The real concern is the increase in the static compression ratio. If you can't find anyone with a thicker Titan MLS HG then get a Cometic MLS HG (Titan's HG appears to be a rebranded Cometic HG, by the way). If you're thinking that going with a Titan HG will let you get away with running on a still less than perfect block and/or head I've got bad news for you though.... While they're both more forgiving they're still not going to live long on a warped, pitted, scratched or coarse deck.

I would look for either a 1.8mm or a 2mm Cometic.

icey756 · 08-19-2012, 12:24 AM

I found a site that had cometic gasket and when i was reading their little article I saw that they recamend going .5mm over your bore size even on stock bore sizes. Is that really suppose to be safer? heres the link. It says this stuff at the bottom. http://www.raceeng.com/techsheets/cometic.pdf

cre · 08-19-2012, 03:24 AM

The HG is always bored out a little higher than the cylinder... even new. Going too big isn't good though either. Has you block been bored? If not 84mm is what you want.

icey756 · 10-15-2012, 02:15 AM

No my block is not bored. I found this one on ebay. Let me know what you think.

http://www.ebay.com/itm/270890709376...84.m1423.l2649

CanadianBak'inSupra · 10-17-2012, 12:23 PM

i payed 240$ for a 1.3mm mls cometic recently.
add up the shipping to the cost it may be worth it to just get it from a local auto parts store.

907mge · 10-19-2012, 01:36 AM

Supra store has the titan 1.4mm MHG for $119. If what cre says is true it should be the same as a cometic.

cre · 10-19-2012, 04:33 AM

Has anyone dealt with Suprastore in the past five years? I'd like to see some actual feedback to know if they've cleaned up their act or not.

Cometic and Titan are visually the same. I've spoken to two store owners who would neither confirm or deny that the two are the same but both agreed that "yes they seem the same". I think the Titan are shipped in bulk packaging where the Cometic have a branded package. The Cometic are available in more sizes, IIRC.

08-17-2012, 11:43 PM	#1
icey756 3" Exhaust Join Date: Jun 2011 Location: Wisconsin Posts: 177	I need a 1.8mm MHG. Will a 1.4mm be ok? I plan on getting a 1.4mm MHG made by titan motor sports. After I got everything back from the machine shop I added up the numbers and It came out to me needing a 1.8mm HG. Will a 1.4mm be ok or will that be too close? I want the Titan MHG because I read that its more forgiving than an HKS or Greddy. Please get back to me quickly if possible. Want to get it ordered asap. Thanks. __________________ 1988 7M-GTE Manual Turbo, Godspeed IC, Stock HG Torque to 90FP W/ Arp bolts, Silicon water hose kit, silicon vacuum hoses, Godspeed radiator, 2 12" electric fans.

08-18-2012, 03:05 PM	#2
icey756 3" Exhaust Join Date: Jun 2011 Location: Wisconsin Posts: 177	Will someone please let me know. I dont want my valves to be hitting my pistons. I know it raises the compression ratio but i dont want it to raise it too much that something goes wrong __________________ 1988 7M-GTE Manual Turbo, Godspeed IC, Stock HG Torque to 90FP W/ Arp bolts, Silicon water hose kit, silicon vacuum hoses, Godspeed radiator, 2 12" electric fans.

08-18-2012, 06:25 PM	#3
btwilson86 Super Moderator Join Date: May 2007 Location: Billings, Montana Posts: 1,034	In stock configuration, these are non-interference engines; you can have a valve fully open and the piston at the top of its stroke, and there will be no contact. Even in an interference engine, the timing would have to be off a considerable amount in order for pistons and valves to make contact. I can't say for sure, but I'm fairly confident that .4 mm will not be enough of a difference to cause contact between the pistons and valves (especially if it is timed properly). __________________ 1989 7MGTE R154 Targa Top White Package w/Blue Interior Driftmotion 57trim CT26, Upgraded Intercooler, 2.25" Hard Pipes, 3" Turbo Back Exhaust with Test Pipe, HKS VPC w/GM 3 bar MAP sensor, APEXi S-AFC, Walbro 255lph fuel pump, ProSport EVO Series Boost / Fuel Pressure / AFR gauges, Lotek a Pillar Gauge Pod, HKS Type 0 Turbo Timer, Eibach Lowering Springs, Tokico Illumina II TEMS struts, custom powder coated Motegi Racing TrakLite wheels

08-18-2012, 07:28 PM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	No it's not enough to turn the engine into an interference motor. The real concern is the increase in the static compression ratio. If you can't find anyone with a thicker Titan MLS HG then get a Cometic MLS HG (Titan's HG appears to be a rebranded Cometic HG, by the way). If you're thinking that going with a Titan HG will let you get away with running on a still less than perfect block and/or head I've got bad news for you though.... While they're both more forgiving they're still not going to live long on a warped, pitted, scratched or coarse deck. I would look for either a 1.8mm or a 2mm Cometic. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

08-19-2012, 12:24 AM	#5
icey756 3" Exhaust Join Date: Jun 2011 Location: Wisconsin Posts: 177	I found a site that had cometic gasket and when i was reading their little article I saw that they recamend going .5mm over your bore size even on stock bore sizes. Is that really suppose to be safer? heres the link. It says this stuff at the bottom. http://www.raceeng.com/techsheets/cometic.pdf __________________ 1988 7M-GTE Manual Turbo, Godspeed IC, Stock HG Torque to 90FP W/ Arp bolts, Silicon water hose kit, silicon vacuum hoses, Godspeed radiator, 2 12" electric fans.

08-19-2012, 03:24 AM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The HG is always bored out a little higher than the cylinder... even new. Going too big isn't good though either. Has you block been bored? If not 84mm is what you want. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

10-15-2012, 02:15 AM	#7
icey756 3" Exhaust Join Date: Jun 2011 Location: Wisconsin Posts: 177	No my block is not bored. I found this one on ebay. Let me know what you think. http://www.ebay.com/itm/270890709376...84.m1423.l2649 __________________ 1988 7M-GTE Manual Turbo, Godspeed IC, Stock HG Torque to 90FP W/ Arp bolts, Silicon water hose kit, silicon vacuum hoses, Godspeed radiator, 2 12" electric fans.

10-17-2012, 12:23 PM	#8
CanadianBak'inSupra Official hall monitor / search nazi - NO SOUP FOR YOU! Join Date: Oct 2009 Location: Canada, BC Posts: 837	i payed 240$ for a 1.3mm mls cometic recently. add up the shipping to the cost it may be worth it to just get it from a local auto parts store. __________________ 1984 supra - 1uzfe - w58 - 4.10 - 1 piece aluminum shaft.

10-19-2012, 01:36 AM	#9
907mge 20psi boost Join Date: Dec 2009 Location: Harrisburg Posts: 759	Supra store has the titan 1.4mm MHG for $119. If what cre says is true it should be the same as a cometic.

10-19-2012, 04:33 AM	#10
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Has anyone dealt with Suprastore in the past five years? I'd like to see some actual feedback to know if they've cleaned up their act or not. Cometic and Titan are visually the same. I've spoken to two store owners who would neither confirm or deny that the two are the same but both agreed that "yes they seem the same". I think the Titan are shipped in bulk packaging where the Cometic have a branded package. The Cometic are available in more sizes, IIRC. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->